MoonLake Immunotherapeutics (MLTX) 10-Q7 Nov 242024 Q3 Quarterly reportFinancial data

Company Profile

Cover

Cover - shares	9 Months Ended
Cover - shares	Sep. 30, 2024	Nov. 01, 2024
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2024
Document Transition Report	false
Entity File Number	001-39630
Entity Registrant Name	MOONLAKE IMMUNOTHERAPEUTICS
Entity Incorporation, State or Country Code	E9
Entity Tax Identification Number	98-1711963
Entity Address, Address Line One	Dorfstrasse 29
Entity Address, Postal Zip Code	6300
Entity Address, City or Town	Zug
Entity Address, Country	CH
City Area Code	41
Local Phone Number	415108022
Title of 12(b) Security	Class A ordinary share, par value $0.0001 per share
Trading Symbol	MLTX
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Amendment Flag	false
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--12-31
Entity Central Index Key	0001821586
Common Class A
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		63,063,929
Common Class C
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		841,269

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($)	Sep. 30, 2024	Dec. 31, 2023
Current assets
Cash and cash equivalents	$ 375,656,291	$ 451,169,337
Short-term marketable debt securities	118,268,400	59,838,900
Other receivables	2,407,062	1,056,862
Prepaid expenses - current	15,984,425	2,102,203
Total current assets	512,316,178	514,167,302
Non-current assets
Operating lease right-of-use assets	3,251,197	3,628,480
Property and equipment, net	581,378	320,865
Prepaid expenses - non-current	2,064,575	8,423,468
Total non-current assets	5,897,150	12,372,813
Total assets	518,213,328	526,540,115
Current liabilities
Trade and other payables	10,710,603	1,837,684
Short-term portion of operating lease liabilities	1,444,893	1,197,876
Accrued expenses and other current liabilities	7,925,524	6,930,120
Total current liabilities	20,081,020	9,965,680
Non-current liabilities
Long-term portion of operating lease liabilities	1,935,709	2,499,990
Pension liability	694,959	583,426
Total non-current liabilities	2,630,668	3,083,416
Total liabilities	22,711,688	13,049,096
Commitments and contingencies (Note 15)
Equity
Additional paid-in capital	675,343,443	609,969,236
Accumulated deficit	(189,988,477)	(116,657,472)
Accumulated other comprehensive income	2,833,970	2,357,621
Total shareholders’ equity	488,195,325	495,675,683
Noncontrolling interests	7,306,315	17,815,336
Total equity	495,501,640	513,491,019
Total liabilities and equity	518,213,328	526,540,115
Common Class A
Equity
Common shares	6,305	6,047
Common Class C
Equity
Common shares	$ 84	$ 251

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Sep. 30, 2024	Dec. 31, 2023
Common Class A
Common shares, par value (USD per share)	$ 0.0001	$ 0.0001
Common shares, shares authorized (in shares)	500,000,000	500,000,000
Common shares, shares issued (in shares)	63,046,025	60,466,453
Common shares, shares outstanding (in shares)	63,046,025	60,466,453
Common Class C
Common shares, par value (USD per share)	$ 0.0001	$ 0.0001
Common shares, shares authorized (in shares)	100,000,000	100,000,000
Common shares, shares issued (in shares)	841,269	2,505,476
Common shares, shares outstanding (in shares)	841,269	2,505,476

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Operating expenses
Research and development	$ (35,735,514)	$ (7,585,136)	$ (72,411,709)	$ (23,704,087)
General and administrative	(7,376,495)	(5,391,607)	(21,099,001)	(15,390,117)
Total operating expenses	(43,112,009)	(12,976,743)	(93,510,710)	(39,094,204)
Operating loss	(43,112,009)	(12,976,743)	(93,510,710)	(39,094,204)
Other income, net	7,089,691	1,386,313	18,903,070	2,952,557
Loss before income tax	(36,022,318)	(11,590,430)	(74,607,640)	(36,141,647)
Income tax expense	(92,106)	(28,923)	(241,059)	(50,080)
Net loss	(36,114,424)	(11,619,353)	(74,848,699)	(36,191,727)
Of which: net loss attributable to controlling interests shareholders	(35,390,337)	(9,426,049)	(73,331,005)	(28,570,184)
Of which: net loss attributable to noncontrolling interests shareholders	(724,087)	(2,193,304)	(1,517,694)	(7,621,543)
Net unrealized gain (loss) on marketable securities and short term investments	(325,510)	3,437,291	508,860	3,046,538
Actuarial gain (loss) on employee benefit plans	(115,629)	39,157	(110,878)	(19,323)
Other comprehensive income (loss)	(441,139)	3,476,448	397,982	3,027,215
Comprehensive loss	(36,555,563)	(8,142,905)	(74,450,717)	(33,164,512)
Comprehensive loss attributable to controlling interests shareholders	(35,822,526)	(6,590,259)	(72,941,435)	(26,095,926)
Comprehensive loss attributable to noncontrolling interests	$ (733,037)	$ (1,552,646)	$ (1,509,282)	$ (7,068,586)
Weighted-average number of shares, basic (in shares)	62,896,782	53,517,655	62,803,220	45,485,650
Weighted-average number of shares, diluted (in shares)	62,896,782	53,517,655	62,803,220	45,485,650
Basic net loss per share attributable to controlling interest shareholders (USD per share)	$ (0.56)	$ (0.18)	$ (1.17)	$ (0.63)
Diluted net loss per share attributable to controlling interest shareholders (USD per share)	$ (0.56)	$ (0.18)	$ (1.17)	$ (0.63)
Common Class A
Operating expenses
Weighted-average number of shares, basic (in shares)	62,896,782	53,517,655	62,803,220	45,485,650
Weighted-average number of shares, diluted (in shares)	62,896,782	53,517,655	62,803,220	45,485,650
Basic net loss per share attributable to controlling interest shareholders (USD per share)	$ (0.56)	$ (0.18)	$ (1.17)	$ (0.63)
Diluted net loss per share attributable to controlling interest shareholders (USD per share)	$ (0.56)	$ (0.18)	$ (1.17)	$ (0.63)

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($)	Total	Common Class A	Common Class C	Total Shareholders' Equity	Common Stock Common Class A	Common Stock Common Class C	Additional Paid-In Capital	Accumulated Deficit	Accumulated Other Comprehensive Income	Noncontrolling Interests
Common stock, beginning balance (in shares) at Dec. 31, 2022					38,977,600	13,723,511
Equity, beginning balance at Dec. 31, 2022	$ 68,766,698			$ 48,898,296	$ 3,898	$ 1,373	$ 129,192,291	$ (80,650,212)	$ 350,946	$ 19,868,402
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation under the ESPP, ESOP, Equity Incentive Plan and reverse vesting of Restricted Founder Shares	2,577,187			1,875,992			1,875,992			701,195
Refund of stamp duty fees	4,923			3,517			3,517			1,406
Net loss	(12,218,987)			(9,004,856)				(9,004,856)		(3,214,131)
Other comprehensive income (loss)	(17,672)			(12,625)					(12,625)	(5,047)
Conversion and transfer of shares between classes (in shares)					176,603	(176,603)
Conversion of MoonLake Class C Ordinary Shares into Class A Ordinary Shares	0			238,836	$ 18	$ (18)	237,049		1,787	(238,836)
Common stock, ending balance (in shares) at Mar. 31, 2023					39,154,203	13,546,908
Equity, end balance at Mar. 31, 2023	59,112,149			41,999,160	$ 3,916	$ 1,355	131,308,849	(89,655,068)	340,108	17,112,989
Common stock, beginning balance (in shares) at Dec. 31, 2022					38,977,600	13,723,511
Equity, beginning balance at Dec. 31, 2022	68,766,698			48,898,296	$ 3,898	$ 1,373	129,192,291	(80,650,212)	350,946	19,868,402
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(36,191,727)
Other comprehensive income (loss)	3,027,215
Common stock, ending balance (in shares) at Sep. 30, 2023					53,561,488	8,884,517
Equity, end balance at Sep. 30, 2023	489,642,186			424,933,000	$ 5,356	$ 889	531,271,953	(109,220,396)	2,875,198	64,709,186
Common stock, beginning balance (in shares) at Mar. 31, 2023					39,154,203	13,546,908
Equity, beginning balance at Mar. 31, 2023	59,112,149			41,999,160	$ 3,916	$ 1,355	131,308,849	(89,655,068)	340,108	17,112,989
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation under the ESPP, ESOP, Equity Incentive Plan and reverse vesting of Restricted Founder Shares	1,497,661			1,247,416			1,247,416			250,245
Net loss	(12,353,387)			(10,139,279)				(10,139,279)		(2,214,108)
Other comprehensive income (loss)	(431,561)			(348,906)					(348,906)	(82,655)
Conversion and transfer of shares between classes (in shares)					4,587,713	(4,587,713)
Conversion of MoonLake Class C Ordinary Shares into Class A Ordinary Shares	0			5,753,517	$ 459	$ (459)	5,709,595		43,922	(5,753,517)
Issuance of Class A Ordinary Shares, net of transaction costs (in shares)					9,744,894
Issuance of Class A Ordinary Shares, net of transaction costs (Note 11)	451,285,093			451,285,093	$ 974		451,284,119
Common stock, ending balance (in shares) at Jun. 30, 2023					53,486,810	8,959,195
Equity, end balance at Jun. 30, 2023	499,109,955			489,797,001	$ 5,349	$ 896	589,549,979	(99,794,347)	35,124	9,312,954
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation under the ESPP, ESOP, Equity Incentive Plan and reverse vesting of Restricted Founder Shares	1,425,651			1,238,144			1,238,144			187,507
Net loss	(11,619,353)			(9,426,049)				(9,426,049)		(2,193,304)
Other comprehensive income (loss)	3,476,448			2,835,790					2,835,790	640,658
Conversion and transfer of shares between classes (in shares)					74,678	(74,678)
Conversion of MoonLake Class C Ordinary Shares into Class A Ordinary Shares	0			548,740	$ 7	$ (7)	545,591		3,149	(548,740)
Capital injection from MoonLake to MoonLake AG (Note 11)	(2,750,515)			(60,060,626)			(60,061,761)		1,135	57,310,111
Common stock, ending balance (in shares) at Sep. 30, 2023					53,561,488	8,884,517
Equity, end balance at Sep. 30, 2023	489,642,186			424,933,000	$ 5,356	$ 889	531,271,953	(109,220,396)	2,875,198	64,709,186
Common stock, beginning balance (in shares) at Dec. 31, 2023		60,466,453	2,505,476		60,466,453	2,505,476
Equity, beginning balance at Dec. 31, 2023	513,491,019			495,675,683	$ 6,047	$ 251	609,969,236	(116,657,472)	2,357,621	17,815,336
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation under the ESPP, ESOP, Equity Incentive Plan and reverse vesting of Restricted Founder Shares	1,677,208			1,693,101			1,693,101			(15,893)
Net loss	(13,975,521)			(13,673,656)				(13,673,656)		(301,865)
Other comprehensive income (loss)	263,503			257,949					257,949	5,554
Conversion and transfer of shares between classes (in shares)					1,493,356	(1,493,356)
Conversion of MoonLake Class C Ordinary Shares into Class A Ordinary Shares	0			10,613,583	$ 149	$ (149)	10,536,980		76,603	(10,613,583)
Buyback of unvested MoonLake AG Common Shares by MoonLake AG into treasury following an employee contract termination (Note 11)	(50)			114,058			113,154		904	(114,108)
Capital injection from MoonLake to MoonLake AG (Note 11)	$ (1,609,961)			(4,667,177)			(4,667,196)		19	3,057,216
Cancellation of Class C shares following an employee contract termination in MoonLake AG (in shares)	(16,853)					(16,853)
Cancellation of MoonLake Class C Ordinary Shares following an employee contract termination in MoonLake AG (Note 11)	$ 0					$ (2)	2
Issuance of Class A Ordinary Shares, net of transaction costs (in shares)	914,828				914,828
Issuance of Class A Ordinary Shares, net of transaction costs (Note 11)	$ 52,540,190			52,540,190	$ 91		52,540,099
Common stock, ending balance (in shares) at Mar. 31, 2024					62,874,637	995,267
Equity, end balance at Mar. 31, 2024	552,386,388			542,553,731	$ 6,287	$ 100	670,185,376	(130,331,128)	2,693,096	9,832,657
Common stock, beginning balance (in shares) at Dec. 31, 2023		60,466,453	2,505,476		60,466,453	2,505,476
Equity, beginning balance at Dec. 31, 2023	513,491,019			495,675,683	$ 6,047	$ 251	609,969,236	(116,657,472)	2,357,621	17,815,336
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(74,848,699)
Other comprehensive income (loss)	397,982
Common stock, ending balance (in shares) at Sep. 30, 2024		63,046,025	841,269		63,046,025	841,269
Equity, end balance at Sep. 30, 2024	495,501,640			488,195,325	$ 6,305	$ 84	675,343,443	(189,988,477)	2,833,970	7,306,315
Common stock, beginning balance (in shares) at Mar. 31, 2024					62,874,637	995,267
Equity, beginning balance at Mar. 31, 2024	552,386,388			542,553,731	$ 6,287	$ 100	670,185,376	(130,331,128)	2,693,096	9,832,657
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation under the ESPP, ESOP, Equity Incentive Plan and reverse vesting of Restricted Founder Shares	1,828,245			1,813,207			1,813,207			15,038
Net loss	(24,758,754)			(24,267,012)				(24,267,012)		(491,742)
Other comprehensive income (loss)	575,618			563,811					563,811	11,807
Common stock, ending balance (in shares) at Jun. 30, 2024					62,874,637	995,267
Equity, end balance at Jun. 30, 2024	530,031,497			520,663,737	$ 6,287	$ 100	671,998,583	(154,598,140)	3,256,907	9,367,760
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation under the ESPP, ESOP, Equity Incentive Plan and reverse vesting of Restricted Founder Shares	1,842,609			1,827,571			1,827,571			15,038
Refund of stamp duty fees	91,799			89,915			89,915			1,884
Net loss	(36,114,424)			(35,390,337)				(35,390,337)		(724,087)
Other comprehensive income (loss)	$ (441,139)			(432,189)					(432,189)	(8,950)
Stock options exercised (in shares)	17,390				17,390
Options exercised under the Equity Incentive Plan (Note 11)	$ 91,298			91,298	$ 2		91,296
Conversion and transfer of shares between classes (in shares)					153,998	(153,998)
Conversion of MoonLake Class C Ordinary Shares into Class A Ordinary Shares	0			1,345,330	$ 16	$ (16)	1,336,078		9,252	(1,345,330)
Common stock, ending balance (in shares) at Sep. 30, 2024		63,046,025	841,269		63,046,025	841,269
Equity, end balance at Sep. 30, 2024	$ 495,501,640			$ 488,195,325	$ 6,305	$ 84	$ 675,343,443	$ (189,988,477)	$ 2,833,970	$ 7,306,315

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	9 Months Ended
CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	Sep. 30, 2024	Sep. 30, 2023
Cash flow from operating activities
Net loss	$ (74,848,699)	$ (36,191,727)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	83,440	9,869
Share-based compensation expense	5,348,062	5,500,499
Net periodic pension benefit (gain) cost for the qualified pension plan	(2,678)	(50,740)
Other non-cash items	1,189,056	96,364
Changes in operating assets and liabilities:
Other receivables	(1,350,200)	(503,626)
Operating lease right-of-use assets	(5,443)	0
Prepaid expenses	(7,523,329)	869,187
Trade and other payables	8,872,919	3,149,756
Operating lease liabilities	(872,121)	(117,832)
Accrued expenses and other current liabilities	995,404	(3,195,591)
Net cash flow used in operating activities	(68,113,589)	(30,433,841)
Cash flow from investing activities
Purchase of short-term marketable debt securities	(203,334,691)	(175,732,711)
Proceeds from maturities of short-term marketable debt securities	145,414,050	33,681,688
Purchase of property and equipment	(343,953)	0
Net cash flow used in investing activities	(58,264,594)	(142,051,023)
Cash flow from financing activities
Issuance of Class A Ordinary Shares, net of transaction costs	52,540,190	451,285,093
Stamp duty on capital injection from MoonLake to MoonLake AG	(1,470,436)	0
Proceeds from options exercised under the Equity Incentive Plan	91,298	0
Buyback of unvested MoonLake AG Common Shares by MoonLake AG following an employee contract termination	(50)	0
Net cash flow provided by financing activities	51,161,002	451,285,093
Effect of movements in exchange rates on cash held	(295,865)	(140,047)
Net change in cash and cash equivalents	(75,513,046)	278,660,182
Cash and cash equivalents, beginning of period	451,169,337	39,505,627
Cash and cash equivalents, end of period	375,656,291	318,165,809
Supplementary disclosure of cash flow information:
Non-cash operating lease right-of-use assets obtained in exchange for lease obligations	$ 554,857	$ 0

Overview of the Company

Overview of the Company	9 Months Ended
Overview of the Company	Sep. 30, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Overview of the Company	Overview of the Company Corporate Information MoonLake Immunotherapeutics is a clinical stage biotechnology company advancing therapies to address significant unmet needs in inflammatory skin and joint diseases. MoonLake Immunotherapeutics is currently a single asset company focused on the development of Sonelokimab (“SLK”), a novel tri-specific IL-17A and IL-17F inhibiting Nanobody that has the potential, based on response levels seen in clinical trials, to drive disease modification in dermatology and rheumatology patients. Unless the context otherwise requires, “MoonLake” and the “Company” refer to the combined company following the Business Combination (as defined in Note 2 — Business Combination Agreement with Helix and Recapitalization

Basis of Presentation and Signi

Basis of Presentation and Significant Accounting Policies	9 Months Ended
Basis of Presentation and Significant Accounting Policies	Sep. 30, 2024
Accounting Policies [Abstract]
Basis of Presentation and Significant Accounting Policies	Basis of Presentation and Significant Accounting Policies Basis of Presentation The accompanying unaudited condensed consolidated financial statements include those of the Company and its subsidiaries, MoonLake Immunotherapeutics AG, a Swiss stock corporation (Aktiengesellschaft) registered with the commercial register of the Canton of Zug, Switzerland under the number CHE-433.093.536 (“MoonLake AG”), MoonLake Immunotherapeutics Ltd., a private limited company incorporated in the United Kingdom, and MNLK Immunotherapeutics, Unipessoal Lda ("MNLK PT"), a private limited company incorporated in Portugal, after elimination of all intercompany accounts and transactions. The accompanying unaudited condensed consolidated financial statements and notes hereto have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) as set forth by the Financial Accounting Standards Board (“FASB”) and in conformity with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X for interim financial reporting. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete financial statements. Any reference in these notes to applicable guidance is meant to refer to the authoritative U.S. GAAP as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Updates (“ASU”) of the FASB. In the opinion of management, all material adjustments necessary for a fair presentation of the financial information, which are of a normal and recurring nature, have been made for the interim periods reported. Results of operations for the three and nine months ended September 30, 2024 are not necessarily indicative of the results for the entire fiscal year or any other period. The unaudited condensed consolidated financial information for the three and nine months ended September 30, 2024 and 2023 have been prepared on the same basis as and should be read in conjunction with MoonLake’s audited financial statements and notes thereto for the year ended December 31, 2023 included in the Annual Report. All amounts are presented in U.S. Dollar (“$”), unless otherwise indicated. The term “Swiss franc” and “CHF” refer to the legal currency of Switzerland, "GBP" refers to the legal currency of the United Kingdom, and “€” and "Euro" refer to the legal currency of Portugal. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires the Company to make judgments, estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements and the reported amounts of expenses. The significant judgments, estimates and assumptions relevant to the Company relate to: • determining whether the in-process research and development expenditure (“IPR&D”) has an alternative future use; • determining assumptions used in estimating the fair value of share-based compensation; • estimating the recoverability of the deferred tax asset; and • estimating the amount of accruals in connection with the completion of clinical trial milestones. The Company bases its judgments and estimates on various factors and information, which may include, but are not limited to, the Company’s forecasts and future plans, current economic conditions and observable market-based transactions of its own shares, the results of which form the basis for making judgments about the carrying value of assets and liabilities and recorded amounts of expenses that are not readily apparent from other sources. To the extent there are material differences between the Company’s estimates and the actual results, the Company’s future results of operation may be affected. Cash and Cash Equivalents The Company considers all highly liquid investments with an original maturity of three months or less at the date of purchase to be cash equivalents. Cash and cash equivalents are recorded at cost, which approximates fair value. As of September 30, 2024, the Company considers $59.8 million of short-term marketable debt securities in the form of eurocommercial papers and certificates of deposit to be cash equivalents. As of December 31, 2023, the Company considered $129.4 million of short-term marketable debt securities in the form of eurocommercial papers and certificates of deposit to be cash equivalents. Marketable securities and short-term investments The Company invests in short-term marketable securities in the form of debt securities. At the time of purchase, the Company assesses whether such debt security should be classified as held-to-maturity or available-for-sale debt securities. Debt securities are classified as held-to-maturity when the Company has the positive intent and ability to hold the securities to maturity. Held-to-maturity debt securities are carried at amortized cost, adjusted for accretion of discounts or amortization of premiums to maturity computed under the effective interest method. Such accretion or amortization is included in “Interest and dividend income”. Marketable debt securities not classified as held-to-maturity are classified as available-for-sale and reported at fair value. Net unrealized gains and losses on available-for-sale debt securities are excluded from the determination of earnings and are instead recognized in the “Accumulated other comprehensive income” component of equity until realized. Realized gains and losses on available-for-sale debt securities are computed based upon the historical cost of these securities, using the specific identification method. A decline in the fair value of any security below cost that is deemed other than temporary results in a charge to earnings and the corresponding establishment of a new cost basis for the security. Dividend and interest income are recognized when earned. Realized gains and losses are included in "Other income" and the cost of securities sold is determined using the specific-identification method. Marketable debt securities are classified as either “Cash and cash equivalents” or “Short‑term marketable debt securities” according to their original maturity at the time of acquisition. Changes in unrealized gains and losses pertaining to cash equivalent securities are added back into the consolidated statements of cash flows as those are excluded from the determination of earnings but impact the cash and cash equivalents position. Concentration of Credit Risk Financial instruments that potentially subject the Company to concentration of credit risk consist of cash accounts in large financial institutions which, at times, may exceed the CHF 100,000 deposit protection limit in Switzerland, the $250,000 Federal Deposit Insurance Corporation deposit insurance coverage limit in the United States, the GBP 85,000 Financial Services Compensation Scheme deposit protection limit in the United Kingdom, or the €100,000 Fundo de Garantia de Depósitos deposit protection limit in Portugal. The Company believes it is not exposed to significant credit risk due to the financial strength of the depository institutions in which the cash and cash equivalents are held. Additionally, the Company ensures further protection against credit risk by diversifying its cash holdings across a variety of credit institutions, thereby minimizing the potential impact of any adverse events on a single institution. Further, the Company's investment strategy for cash (in excess of current business requirements) is set to invest in short-term marketable debt securities. Management actively monitors credit risk in the investment portfolio. Credit risk exposures are controlled in accordance with policies approved by the board of directors to identify, measure, monitor and control credit risks. Fair Value Measurements The Company follows the guidance included in ASC 820, Fair Value Measurement . Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. There are three levels of inputs to fair value measurements: • Level 1, meaning the use of quoted prices for identical instruments in active markets; • Level 2, meaning the use of quoted prices for similar instruments in active markets or quoted prices for identical or similar instruments in markets that are not active or are directly or indirectly observable; and • Level 3, meaning the use of unobservable inputs. Observable market data is used when available. Transfers between Levels 1, 2 or 3 within the fair value hierarchy are recognized at the end of the reporting period when the respective transaction occurred. Segment Information The Company operates as a single operating segment. The Company’s chief operating decision maker, its Chief Executive Officer, manages the Company’s operations on a stand-alone basis for the purposes of allocating resources and assessing financial performance. Property and Equipment Property and equipment, net is stated at cost, net of accumulated depreciation. Depreciation is computed using the straight-line method based on the estimated useful lives of three Research and Development Contract Costs and Accruals Research and development expenses include employee payroll, consulting, contract research and contract manufacturing costs attributable to research and development activities and are expensed as incurred. Upfront payments and milestone payments made for the licensing of technology are expensed as research and development expenses in the period in which it is probable that a liability has been incurred. Advance payments for goods or services to be received in the future for use in research and development activities are recorded as prepaid expenses. The prepaid amounts are expensed as the related goods are delivered or the services are performed. The Company has entered into various research and development contracts with companies both inside and outside of the United States. These agreements are generally cancellable, and related payments are recorded as research and development expenses as incurred. The Company records accruals for estimated ongoing research costs. When evaluating the adequacy of the accrued liabilities, the Company analyzes progress of the studies or trials, including the phase or completion of events, invoices received and contracted costs. Significant judgments and estimates are made in determining the accrued balances at the end of any reporting period. Actual results could differ from the Company’s estimates. The Company’s historical accrual estimates have not been materially different from the actual costs. Share-Based Compensation The Company recognizes compensation expense based on estimated fair values for all stock-based payment awards made to eligible employees, members of the board of directors and independent contractors that are expected to vest. The valuation of stock option awards is determined at the date of grant using the Black-Scholes option pricing model. The Black-Scholes option pricing model requires the Company to make assumptions and judgements about the inputs used in the calculations, such as the fair value of the common stock, expected term, expected volatility of the Company’s common stock, risk-free interest rate and expected dividend yield. The valuation of restricted stock awards is measured by the fair value of the Company’s common stock on the date of the grant. Share-based compensation ) has historically been estimated by management with reference to the market-based transaction with its Series A investors, as there was no public market for the common stock. Share-based payment arrangements are accounted for under the fair value method. Total compensation is measured at grant date, based on the fair value of the award at that date, and recorded in earnings over the period the employees are required to render service. The Company recognizes compensation cost only for those awards expected to meet the service conditions on a straight-line basis over the requisite service period of the award. Foreign Currency The functional currency of the Company and its subsidiaries is the U.S. dollar. Balances and transactions denominated in foreign currencies are converted as follows: monetary assets and liabilities are translated using exchange rates in effect at the balance sheet dates and non-monetary assets and liabilities are translated at historical exchange rates. Revenue and expenses are translated at the daily exchange rate on the respective accounting date. Gains or losses from foreign currency translation are included in the consolidated statements of operations and comprehensive loss in "other income, net". The Company recognized foreign currency transaction loss of $26,746 and $125,581 for the three and nine months ended September 30, 2024, respectively, and a foreign currency transaction loss of $557,144 and $276,491 for three and nine months ended September 30, 2023, respectively. Income Taxes The Company accounts for income taxes by using the asset and liability method of accounting for income taxes. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. A valuation allowance is recorded to the extent it is more likely than not that all or a portion of the Company's deferred tax assets will not be realized. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in operations in the period that includes the enactment date. Net Loss per Class A Ordinary Shares Basic net loss per Class A Ordinary Share is calculated using the two-class method under which earnings are allocated to both Class A Ordinary Shares and participating securities. Basic net loss per share is calculated by dividing the net loss attributable to Class A Ordinary Shares by the weighted-average number of Class A Ordinary Shares outstanding for the period. The diluted net loss per Class A Ordinary Share is computed by dividing the net loss using the weighted-average number of Class A Ordinary Shares and, if dilutive, potential Class A Ordinary Shares outstanding during the period. In periods in which the Company reports a net loss attributable to shareholders of Class A Ordinary Shares, diluted net loss per share attributable to shareholders of Class A Ordinary Shares is the same as basic net loss per share attributable to shareholders of Class A Ordinary Shares, since dilutive Class A Ordinary Shares are not assumed to be outstanding if their effect is anti-dilutive. Acquisitions The Company evaluates acquisitions of assets and other similar transactions to assess whether or not the transaction should be accounted for as a business combination or asset acquisition by first assessing whether substantially all of the fair value of the gross assets acquired is concentrated in a single identifiable asset or group of similar identifiable assets. On April 29, 2021, MoonLake AG entered into an in-licensing agreement (the “In-License Agreement”) with Merck Healthcare KGaA, Darmstadt, Germany (“MHKDG”) to acquire the Sonelokimab program (the “SLK Program”) and determined that substantially all of the fair value of the gross assets acquired related to IPR&D of SLK. Therefore, this transaction was accounted for as an asset acquisition. IPR&D represents incomplete technologies that the Company acquires, which at the time of acquisition, are still under development and have no alternative future use. The fair value of such technologies is expensed upon acquisition. A technology is considered to have an alternative future use if it is probable that the Company will use the asset in its current, incomplete state as it existed at the acquisition date, in another research and development project that has not yet commenced, and economic benefit is anticipated from that use. If a technology is determined to have an alternative future use, then the fair value of the program would be recorded as an asset on the balance sheet rather than expensed. Contingent consideration payments (for example milestone payments due upon the occurrence of a specific event) in asset acquisitions are recognized in the period in which it is probable that a liability has been incurred (unless the contingent consideration meets the definition of a derivative, in which case the amount becomes part of the cost in the asset acquired). Upon recognition of the contingent consideration payment, the amount is expensed if it relates to IPR&D or capitalized if it relates to a developed product which is generally considered to be when clinical trials have been completed and regulatory approval obtained. Future royalty payments due on net sales will be recognized in cost of goods sold when net sales are recognized. Pension Accounting The Company accounts for pension assets and liabilities in accordance with ASC 715, Compensation – Retirement Benefits , which requires the recognition of the funded status of pension plans in the Company’s consolidated balance sheet. The liability in respect to defined benefit pension plans is the projected benefit obligation calculated annually by independent actuaries using the projected unit credit method. The projected benefit obligation as of September 30, 2024 represents the actuarial present value of the estimated future payments required to settle the obligation that is attributable to employee services rendered before that date. Service costs for such pension plans, represented in the net periodic pension benefit cost, are included in the personnel expenses of the various functions where the employees are engaged. The other components of net benefit cost are included in the consolidated statements of operations and comprehensive loss separately from the service cost component, in “other income, net.” Plan assets are recorded at their fair value. Gains or losses arising from plan curtailments or settlements are accounted for at the time they occur. Any net pension asset is limited to the present value of the future economic benefits available to the Company in the form of refunds from the plan or expected reductions in future contributions to the plan. Actuarial gains and losses arising from differences between the actual and the expected return on plan assets are recognized in accumulated other comprehensive income. Leases The Company determines if an arrangement is or contains a lease at contract inception. For these arrangements, it is evaluated if the arrangement involves an identified asset that is physically distinct or whether the Company has the right to substantially all of the capacity of an identified asset that is not physically distinct. In arrangements that involve an identified asset, there is also judgment in evaluating if the Company has the right to direct the use of that asset. MoonLake does not have any finance leases. As of September 30, 2024, the Company has five operating leases related to the office spaces located in (i) Dorfstrasse 29, 6300, Zug, Switzerland (comprised of two leases), (ii) 95 Regent Street, CB2 1AW, Cambridge, England, United Kingdom, and (iii) Rua Manuel Pinto de Azedevo 860, 4150-335, Porto, Portugal (comprised of two leases). The operating leases are recognized on a straight-line basis over the lease term commencing on the date the Company has the right to use the leased property. Right-of-use assets and lease liabilities are measured at the lease commencement date based on the present value of the remaining lease payments over the lease term, determined using the discount rate for the lease at the commencement date. Because the rate implicit in the leases is not readily determinable, the Company uses the incremental borrowing rate as the discount rate, which approximates the interest rate at which the Company could borrow on a collateralized basis with similar terms and payments and in similar economic environments. Leases with an initial term of 12 months or less that do not have the option to purchase the underlying asset are not recorded on the balance sheet, with lease expense for these leases recognized on a straight-line basis over the lease term commencing on the date the Company has the right to use the leased property. Recently Issued Accounting Pronouncements not yet Adopted In November 2023, the FASB issued ASU 2023-07, Segment reporting — Improvements to Reportable Segment Disclosures. This new standard requires public entities to disclose significant segment expenses and additional segment items annually and to provide all reported segment profit or loss and assets disclosures currently required annually on an interim basis. The standard also requires disclosure of the Chief Operating Decision Maker's title and position. The standard does not change the manner in which public entities identify their operating segments, aggregate them, or apply the quantitative thresholds for determining their reportable segments. It is effective for fiscal years beginning after December 15, 2023 and interim periods in fiscal years beginning after December 15, 2024, with early adoption permitted. The Company has determined it operates as a single segment, therefore, we do not anticipate this ASU to materially impact our consolidated financial statements and related disclosures. In December 2023, the FASB issued ASU 2023-09, Income taxes — Improvements to Income Taxes Disclosure. The purpose of this guidance is to enhance the transparency and usefulness of income tax disclosures and provide comprehensive income tax information, particularly in relation to rate reconciliation and income taxes paid in the U.S and foreign jurisdictions. It is effective for fiscal years beginning after December 15, 2024 and interim periods in fiscal years beginning after December 15, 2024, with early adoption permitted. This ASU will result in the required additional disclosures being included in our consolidated financial statements, once adopted.

Risks and Liquidity

Risks and Liquidity	9 Months Ended
Risks and Liquidity	Sep. 30, 2024
Risks and Uncertainties [Abstract]
Risks and Liquidity	Risks and Liquidity Going Concern, Liquidity and Capital Resources MoonLake is subject to risks common to companies in the biopharmaceutical industry, and the Company believes that changes in any of the following areas could have a material adverse effect on the Company's future financial position or results of operations: ability to obtain future financing, regulatory approval and market acceptance of, and reimbursement for, product candidates, performance of third-party contract research organizations and manufacturers upon which the Company relies, protection of the Company's intellectual property, litigation or claims against the Company based on intellectual property, patent, product, regulatory, clinical or other factors, and the Company's ability to attract and retain employees necessary to support its growth. The Company is dependent on third-party manufacturers to supply products for research and development activities in its programs. In particular, the Company relies and expects to continue to rely on a small number of manufacturers to supply the Company with its requirements for the active pharmaceutical ingredients and formulated drugs related to these programs. These programs could be adversely affected by a significant interruption in the supply of active pharmaceutical ingredients and formulated drugs. The Company's ability to generate revenue sufficient to achieve profitability will depend on the successful development and eventual commercialization of SLK in one or more indications, which is expected to take a number of years. The Company expects to continue to incur significant expenses and operating losses for at least the next three years as the Company continues the development of SLK and prepares for commercial launches. It is expected that operating losses will fluctuate significantly from year to year depending on the timing of the Company's planned clinical development programs and efforts to achieve regulatory approval. The Company incurred a loss of $74.8 million for the nine months ended September 30, 2024. As of September 30, 2024, the Company’s current assets exceeded its current liabilities by $492.2 million.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
Fair Value Measurements	Sep. 30, 2024
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The following table presents information about the Company's short-term marketable debt securities measured at fair value on a recurring basis and indicate the level in the fair value hierarchy in which the Company classifies the fair value measurement: September 30, 2024 December 31, 2023 Level 2 Total Level 2 Total Eurocommercial Papers $ 89,072,100 $ 89,072,100 $ 109,608,915 $ 109,608,915 Certificates of Deposit 88,991,100 88,991,100 79,626,727 79,626,727 Total $ 178,063,200 $ 178,063,200 $ 189,235,642 $ 189,235,642 Cash and accounts payable approximate their fair values as of September 30, 2024 and December 31, 2023, due to their short-term nature. Pension plan assets fair value is determined based on Level 2 inputs.

Investments

Investments	9 Months Ended
Investments	Sep. 30, 2024
Investments, Debt and Equity Securities [Abstract]
Investments	Investments The fair value and amortized cost of investments in short-term marketable debt securities by major security type as of September 30, 2024 are as follows: Amortized cost Gross unrealized gains Gross unrealized losses Fair value Eurocommercial Papers $ 87,231,307 $ 1,840,793 $ — $ 89,072,100 Certificates of Deposit 87,602,179 1,388,921 — 88,991,100 Total $ 174,833,486 $ 3,229,714 $ — $ 178,063,200 Of which classified within cash and cash equivalents 59,212,123 582,677 — 59,794,800 Of which classified within short-term marketable debt securities 115,621,363 2,647,037 — 118,268,400 The following table presents the changes in fair values of the Company’s short-term marketable debt securities, classified as Level 2 financial assets, and recognized in accumulated other comprehensive income: Beginning balance, January 1, 2024 $ 2,720,854 Other comprehensive income before reclassifications 13,000,645 Amounts reclassified from accumulated other comprehensive income (12,491,785) Ending balance, September 30, 2024 $ 3,229,714 As of September 30, 2024, the Company’s marketable debt securities maturities are all due within one year.

Prepaid Expenses

Prepaid Expenses	9 Months Ended
Prepaid Expenses	Sep. 30, 2024
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid Expenses	Prepaid Expenses Prepaid expenses - current September 30, 2024 December 31, 2023 Non-clinical research and clinical development services $ 7,381,811 $ 842,729 Supply and manufacturing services 6,358,892 1,205 Insurance 1,496,521 1,077,478 Other prepayments 747,201 180,791 Total $ 15,984,425 $ 2,102,203 Prepaid expenses - non-current September 30, 2024 December 31, 2023 Supply and manufacturing services $ 2,064,575 $ 8,423,468 Total $ 2,064,575 $ 8,423,468 Supply and manufacturing services, current and non-current, relate to advance payments made to a contract manufacturing organization pursuant to a manufacturing run reservation agreement for the commercial-scale manufacturing of SLK in 2025.

Trade and Other Payables

Trade and Other Payables	9 Months Ended
Trade and Other Payables	Sep. 30, 2024
Payables and Accruals [Abstract]
Trade and Other Payables	Trade and Other Payables September 30, 2024 December 31, 2023 Research and development services and license fees $ 7,113,098 $ 911,454 Supply and manufacturing fees payable 3,044,237 553,459 Consulting and advisory services 307,581 80,695 Legal advisory fees payable 104,317 47,095 Other payables 141,370 244,981 Total $ 10,710,603 $ 1,837,684 September 30, 2024 December 31, 2023 Research and development services and license fees $ 3,253,581 $ 1,226,281 Bonuses and related employees compensation expenses 2,922,982 2,780,219 Supply and manufacturing services 894,894 1,603,739 Tax liabilities 484,482 367,976 Consultant and other fees 351,774 853,905 Legal fees 17,811 98,000 Total $ 7,925,524 $ 6,930,120

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	9 Months Ended
Accrued Expenses and Other Current Liabilities	Sep. 30, 2024
Payables and Accruals [Abstract]
Accrued Expenses and Other Current Liabilities	Trade and Other Payables September 30, 2024 December 31, 2023 Research and development services and license fees $ 7,113,098 $ 911,454 Supply and manufacturing fees payable 3,044,237 553,459 Consulting and advisory services 307,581 80,695 Legal advisory fees payable 104,317 47,095 Other payables 141,370 244,981 Total $ 10,710,603 $ 1,837,684 September 30, 2024 December 31, 2023 Research and development services and license fees $ 3,253,581 $ 1,226,281 Bonuses and related employees compensation expenses 2,922,982 2,780,219 Supply and manufacturing services 894,894 1,603,739 Tax liabilities 484,482 367,976 Consultant and other fees 351,774 853,905 Legal fees 17,811 98,000 Total $ 7,925,524 $ 6,930,120

Leases

Leases	9 Months Ended
Leases	Sep. 30, 2024
Leases [Abstract]
Leases	Leases In August 2021, the Company entered into an open-ended office lease agreement, effective November 1, 2021, to lease approximately 2,300 square feet of space on the last two floors of the building located at Dorfstrasse 29, 6300 Zug, Switzerland. The Company estimated the effective duration of the lease at inception and determined a period of 3 years, with expected expiration in November 2024. In December 2023, the contract was extended, leading to a new estimated effective duration of the lease period of 3 years, with expected expiration in January 2027. On October 9, 2023, the Company entered into an office lease agreement, effective as of October 9, 2023, to lease approximately 3,900 square feet of office space on the fifth floor of the building located at Rua Manuel Pinto de Azedevo 860, 4150-335, Porto, Portugal. This lease has a 3-year initial term, with two extendable periods of 3 years each. It is expected to be extended once until October 2029. On October 13, 2023, the Company entered into an office lease agreement, effective as of October 16, 2023, to lease approximately 6,000 square feet of office space on the first floor of the building located at 95 Regent Street, CB2 1AW, Cambridge, England, United Kingdom. This lease has a 3-year term agreement and is set to expire in October 2026. On December 12, 2023, the Company entered into an open-ended office lease agreement, effective as of January 15, 2024, to lease approximately 1,700 square feet of additional office space at its existing corporate headquarters located at Dorfstrasse 29, 6300 Zug, Switzerland. The Company estimated the duration of the lease at inception and determined a 3-year term. On August 14, 2024, the Company entered into an office lease agreement, effective as of September 8, 2024, to lease approximately 2,000 square feet of additional office space at its existing office located at Rua Manuel Pinto de Azevodo 860, 4150-335, Porto, Portugal. This lease has a 2-year initial term, with two extendable periods of 3 years each. The Company currently expects that it will be extended until October 2029. The weighted average remaining lease term and weighted average discount rate for the operating leases as of September 30, 2024 and December 31, 2023 were as follows: September 30, 2024 December 31, 2023 Weighted average remaining lease term (in months) 32 39 Weighted average discount rate 4.7 % 4.9 % The maturities of the Company's operating lease liabilities as of September 30, 2024 are as follows: Year ending December 31, Amount Remainder of fiscal 2024 $ 386,519 2025 1,571,589 2026 1,242,550 2027 140,313 2028 140,313 Thereafter 95,627 Total lease payments 3,576,911 Less imputed interest (196,309) Total lease liability 3,380,602 Less current portion of lease liability (1,444,893) Long-term portion operating lease liability $ 1,935,709 Operating cash outflows for amounts included in the measurement of lease liabilities was $1,101,661 and $78,270 for the nine months ended September 30, 2024 and September 30, 2023, respectively. The Company recorded the following lease and variable lease expenses for the three and nine months ended September 30, 2024 and September 30, 2023: Three Months Ended September 30, 2024 Three Months Ended September 30, 2023 Nine Months Ended September 30, 2024 Nine Months Ended September 30, 2023 Operating lease expense $ 358,583 $ 39,562 $ 1,061,029 $ 117,832 Variable lease expense 1 5,398 — 5,398 — Total lease expense $ 363,981 $ 39,562 $ 1,066,427 $ 117,832

Employee Benefit Plans

Employee Benefit Plans	9 Months Ended
Employee Benefit Plans	Sep. 30, 2024
Retirement Benefits [Abstract]
Employee Benefit Plans	Employee Benefit Plans The Company operates a defined benefit pension plan in Switzerland (the "Plan”) and a defined contribution pension plan in the United Kingdom, in accordance with local regulations and practices. As of September 30, 2024, the Plan covers the Company’s employees in Switzerland with benefits in the event of death, disability, retirement, or termination of employment. Components of Net Periodic Benefit Cost under the Plan Three Months Ended September 30, 2024 Three Months Ended September 30, 2023 Nine Months Ended September 30, 2024 Nine Months Ended September 30, 2023 Service cost $ 71,107 $ 31,175 $ 210,387 $ 91,596 Interest cost 8,387 7,784 24,814 22,872 Expected return on plan assets (15,338) (9,280) (45,380) (27,265) Amortization of unrecognized loss 2,609 — 7,717 — Prior service credit recognized in current year (2,582) — (7,639) — Total net periodic benefit cost $ 64,183 $ 29,679 $ 189,899 $ 87,203 The components of net periodic benefit cost other than the service cost component are included in general and administrative expense in the Company's unaudited condensed consolidated statements of operations and comprehensive loss. Employer Contributions under the Plan For the nine months ended September 30, 2024, contributions of $192,563 (CHF 169,455) were made to the Plan. The Company presently anticipates contributing an additional estimated amount of $64,188 (CHF 56,485) to fund the Plan in 2024 for a total of $256,751 (CHF 225,940).

Shareholders_ Equity

Shareholders’ Equity	9 Months Ended
Shareholders’ Equity	Sep. 30, 2024
Equity [Abstract]
Shareholders’ Equity	Shareholders’ Equity Class A Ordinary Shares (1) Class C Ordinary Shares (1) Total Number of Ordinary Shares Authorized Issued Authorized Issued Authorized Issued and Outstanding Balance at January 1, 2024 500,000,000 60,466,453 100,000,000 2,505,476 600,000,000 62,971,929 Conversion of Class C Ordinary Shares into Class A Ordinary Shares — 1,493,356 — (1,493,356) — — Issuance of Class A Ordinary Shares under the ATM facility — 914,828 — — — 914,828 Cancellation of Class C shares following an employee contract termination in MoonLake AG — — — (16,853) — (16,853) Balance at March 31, 2024 500,000,000 62,874,637 100,000,000 995,267 600,000,000 63,869,904 Balance at June 30, 2024 500,000,000 62,874,637 100,000,000 995,267 600,000,000 63,869,904 Conversion of Class C Ordinary Shares into Class A Ordinary Shares — 153,998 — (153,998) — — Options exercised under the Equity Incentive Plan — 17,390 — — — 17,390 Balance at September 30, 2024 500,000,000 63,046,025 100,000,000 841,269 600,000,000 63,887,294 (1) Fully paid-in registered shares with a par value of $0.0001 Class A Ordinary Shares On April 6, 2022, the Company's Class A Ordinary Shares began trading on The Nasdaq Capital Market ("Nasdaq") under the symbol “MLTX”. As of September 30, 2024, there were 63,046,025 Class A Ordinary Shares issued and outstanding. The Company is authorized to issue up to 500,000,000 Class A Ordinary Shares, par value $0.0001 per share. Holders of Class A Ordinary Shares are entitled to one vote per share. Class C Ordinary Shares As of September 30, 2024, there were 841,269 Class C Ordinary Shares issued and outstanding. The Company is authorized to issue up to 100,000,000 Class C Ordinary Shares, with a par value $0.0001 per share. Each Class C Ordinary Share entitles the holders thereof to one vote per share, but carries no economic rights. At the closing of the Business Combination, MoonLake, MoonLake AG and ML Party (as defined in Note 2 — Business Combination Agreement with Helix and Recapitalization , included in MoonLake's audited financial statements and notes thereto for the year ended December 31, 2023 included in the Annual Report) entered into a Restated and Amended Shareholders' Agreement (the “A&R Shareholders' Agreement”). With the intent to approximate the rights, obligations and restrictions that an ML Party would enjoy if it were a holder of Class A Ordinary Shares, the A&R Shareholders’ Agreement (i) imposes certain transfer and other restrictions on the ML Parties, (ii) provides for the waiver of certain statutory rights and (iii) establishes certain mechanics whereby MoonLake and each of the ML Parties are able to effect the conversion of MoonLake AG Common Shares and Class C Ordinary Shares into a number of Class A Ordinary Shares equal to the Exchange Ratio of 33.638698 (as defined in Note 3 — Basis of Presentation , included in MoonLake's audited financial statements and notes thereto for the year ended December 31, 2023 included in the Annual Report). On September 9 and September 25, 2024, pursuant to the A&R Shareholders’ Agreement, certain holders of Class C Ordinary Shares submitted exchange notices to the Company, pursuant to which such holders of Class C Ordinary Shares effected the conversion of 4,578 MoonLake AG Common Shares and 153,998 Class C Ordinary Shares into 153,998 Class A Ordinary Shares using the Exchange Ratio. The foregoing description of the A&R Shareholders' Agreement is not complete and is qualified in its entirety by reference to, and should be read in connection with, the full text of the A&R Shareholders' Agreement filed as an exhibit on the Company's Current Report on Form 8-K filed with the SEC on April 11, 2022. Equity Offerings At-the-Market Offering On May 11, 2023, the Company entered into a Sales Agreement (the “May 2023 Sales Agreement”) with Leerink Partners LLC (formerly known as SVB Securities LLC) (“Leerink Partners”), through which the Company could issue and sell up to $200,000,000 of its Class A Ordinary Shares (the “May 2023 ATM Shares”), through Leerink Partners as its sales agent. The May 2023 ATM Shares to be sold under the May 2023 Sales Agreement, if any, would be issued and sold pursuant to the Company's shelf registration statement on Form S-3 (File No. 333-271546), which was declared effective by the SEC on May 9, 2023, and a prospectus supplement thereto filed with the SEC on May 11, 2023. On June 27, 2023, the Company reduced the maximum aggregate offering amount of its Class A Ordinary Shares that could be issued and sold under the May 2023 Sales Agreement to $0 and no longer intends to sell Class A Ordinary Shares under the May 2023 Sales Agreement unless the Company files a further prospectus supplement indicating an amount of shares proposed to be sold. On August 31, 2023, the Company entered into a Sales Agreement with Leerink Partners (the “August 2023 Sales Agreement” and together with the May 2023 Sales Agreement, the “Sales Agreements”), through which the Company could issue and sell up to $350,000,000 of its Class A Ordinary Shares (the “August 2023 ATM Shares”), through Leerink Partners as its sales agent. The August 2023 ATM Shares to be sold under the August 2023 Sales Agreement, if any, would be issued and sold pursuant to the Company’s shelf registration statement on Form S-3 (File No. 333-274286), which was declared effective by the SEC on September 11, 2023, and a prospectus supplement thereto filed with the SEC on August 31, 2023. During the three months ended March 31, 2024, the Company sold 914,828 Class A Ordinary Shares under the August 2023 Sales Agreement at a weighted average share price of $58.31, for aggregate net proceeds of approximately $52.5 million, after deducting sales agent's commissions and transaction costs. During the three months ended June 30, 2024 and the three months ended September 30, 2024, there were no sales under the August 2023 Sales Agreement. Public Offering of Class A Ordinary Shares On June 27, 2023, the Company entered into an underwriting agreement with SVB Securities LLC and Guggenheim Securities LLC as the representatives of the underwriters named therein, to issue and sell 8,000,000 Class A Ordinary Shares at a public offering price of $50.00 per share (the “Offering”). In addition, the Company granted the underwriters an option for a period of 30 days to purchase up to an additional 1,200,000 Class A Ordinary Shares at the public offering price less the underwriting discounts and commissions (the “Option”), and such Option was exercised in full by the underwriters. The Offering closed on June 30, 2023, and net proceeds from the Offering, including proceeds from the exercise in full by the underwriters of the Option, were $436.7 million, after deducting the underwriting discounts and commissions and the offering expenses in the amount of $23.3 million. Following the completion of the Offering, the Company opted to direct a substantial portion of the net proceeds to MoonLake AG. This was executed as a two-step process: (i) the Company acquired the remaining 22,756 MoonLake AG Common Shares held in treasury through a share purchase and assignment agreement formally executed on July 9, 2023 ($38.9 million) and (ii) the Company contributed additional funds to MoonLake AG’s capital reserves through a cash contribution agreement formally executed on July 10, 2023 ($275 million). A stamp duty tax of $2.8 million was levied on the aforementioned capital contribution which the Company has classified as cash flows from financing activities in order to correctly mirror the underlying nature of the transaction. On March 8, 2024, the Company executed a similar transaction as a two-step process: (i) the Company acquired 501 MoonLake AG Common Shares held in treasury through a share purchase and assignment agreement ($0.8 million) and (ii) the Company contributed an additional $150.0 million of funds to MoonLake AG's capital reserves through a cash contribution. A stamp duty tax of $1.6 million was levied on the capital contribution which the Company has classified as cash flows from financing activities in order to correctly mirror the underlying nature of the transaction. The aforementioned increase in treasury shares occurred during the three months ended March 31, 2024 as a result of an employee termination entitling MoonLake AG to repurchase such employee's unvested shares (501 MoonLake AG Common Shares and 16,853 Class C Ordinary Shares) previously awarded as part of a share-based compensation program. Since the shares were subsequently sold to MoonLake, the corresponding Class C Ordinary Shares were canceled. Options Exercised under the Equity Incentive Plan

Net Loss per Share

Net Loss per Share	9 Months Ended
Net Loss per Share	Sep. 30, 2024
Earnings Per Share [Abstract]
Net Loss per Share	Net Loss per Share The following table sets forth the loss per share calculations for the three and nine months ended September 30, 2024 compared to the three and nine months ended September 30, 2023: Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Numerator Net loss attributable to controlling interests shareholders $ (35,390,337) $ (9,426,049) $ (73,331,005) $ (28,570,184) Denominator Total weighted average number of outstanding shares 62,896,782 53,517,655 62,803,220 45,485,650 Net loss per share – basic and diluted $ (0.56) $ (0.18) $ (1.17) $ (0.63) The weighted average number of shares used to calculate the net loss per share – basic for the nine months ended September 30, 2024 excludes Class C Ordinary Shares as they do not carry economic rights. If the ML Parties elected to convert all of their MoonLake AG Common Shares into Class A Ordinary Shares as of January 1, 2024, the weighted average number of shares outstanding would have been 63,881,246 and 63,809,450 for the three and nine months ended September 30, 2024, respectively, resulting in a net loss per share of $0.57 and $1.17, respectively. Upon conversion, all Class C Ordinary Shares would be forfeited and there would no longer be any noncontrolling interests.

Share-Based Compensation

Share-Based Compensation	9 Months Ended
Share-Based Compensation	Sep. 30, 2024
Share-Based Payment Arrangement [Abstract]
Share-Based Compensation	Share-Based Compensation As of September 30, 2024, the Company had the following share-based compensation arrangements: a. Restricted Founder Shares (as defined below) – created in April 2021 by MoonLake AG (fully vested as of April 2023); b. The Employee Share Participation Plan (“ESPP”) – created in July 2021 by MoonLake AG; c. The Employee Stock Option Plan (“ESOP”) – created in July 2021 by MoonLake AG (fully vested as of January 2024); d. MoonLake Immunotherapeutics 2022 Equity Incentive Plan ("Equity Incentive Plan") – created in April 2022 by MoonLake Immunotherapeutics. The purpose of the arrangements is to attract and retain the best available personnel and to provide participants with additional incentive to increase their efforts on behalf and in the best interest of the Company and its subsidiaries. The reference to “Common Shares” refers to shares in MoonLake AG. MoonLake AG's compensation plans are settled with its Common Shares and with a number of Class C Ordinary Shares of the Company, determined by multiplying the number of Common Shares by the Exchange Ratio. The owners of Common Shares have the right to exchange their Common Shares for a number of Class A Ordinary Shares derived using the Exchange Ratio. In the event MoonLake AG shareholders elect to exchange their Common Shares, such MoonLake AG shareholder forfeits a number of Class C Ordinary Shares equal to the number of Class A Ordinary Shares issued (refer to Note 11 — Shareholders’ Equity - Class C Ordinary Shares ). As of January 1, 2024, the Company executed the conversion of the majority of the outstanding ESOP awards into an equivalent number of Equity Incentive Plan option awards that are settled with Class A Ordinary Shares, thereby eliminating the intermediary right to the exchange step noted above. From an accounting perspective, there is no underlying modification to the economic, control or legal rights of the awards, including vesting terms and conditions, exercise price and accounting classification. This is purely an administrative change as opposed to an accounting modification whereby the plan issuer is amended from MoonLake AG to MoonLake Immunotherapeutics. Consequently, there is no incremental fair value generated following the conversion and therefore no incremental expense recorded. Any remaining unvested compensation expense will be recorded over the remaining vesting period of the original awards, thereby resulting in no change to the consolidated financial statements. As a result of this administrative conversion, the two main plans which remain active as of September 30, 2024 are the ESPP and Equity Incentive Plan, whereas the Restricted Founder Shares and ESOP are fully vested as of April 2023 and January 2024, respectively. For the three and nine months ended September 30, 2024, the Company has recognized an increase in equity in the condensed consolidated balance sheet, and share-based compensation expense in the condensed consolidated statements of operations and comprehensive loss of $1.8 million and $5.3 million, respectively. The share-based compensation expense was driven by the aforementioned two main active share-based compensation plans and programs: Compensation Plan Three Months Ended September 30, 2024 Three Months Ended September 30, 2023 Nine Months Ended September 30, 2024 Nine Months Ended September 30, 2023 MoonLake AG Restricted Founder Shares $ — $ — $ — $ 1,574,299 ESPP 741,154 762,309 2,191,557 2,590,576 ESOP — 255,171 — 614,469 Equity Incentive Plan 1,101,455 408,171 3,156,505 721,155 Total share-based compensation expense $ 1,842,609 $ 1,425,651 $ 5,348,062 $ 5,500,499 Of which: included in research and development expense 508,697 262,717 1,446,049 1,150,815 Of which: included in general and administrative expense 1,333,912 1,162,934 3,902,013 4,349,684 We expect that all future employee awards will be made under the Equity Incentive Plan. As of September 30, 2024, 3,281,755 Class A Ordinary Shares from the authorized pool of 4,353,948 Class A Ordinary Shares remain available for future grants, and 973,800 and 98,393 Class A Ordinary Shares are reserved for issuance upon exercise of stock options granted under the Equity Incentive Plan and ESOP, respectively. The latter relate to awards not yet subjected to the conversion described above. MoonLake AG - Restricted Founder Shares On April 28, 2021, the shareholders’ agreement between the co-founders, the Series A investors and MoonLake AG imposed a reverse vesting condition on 90% of the total 110,000 Common Shares (the equivalent of 3,700,257 Class C Ordinary Shares) held by each of the three co-founders. Therefore, 99,000 Common Shares (the equivalent of 3,330,231 Class C Ordinary Shares) held by each of the co-founders were subject to these restrictions and considered unvested (the “Restricted Founder Shares”). The Restricted Founder Shares vested on the 28th of each month at a rate of 4.166% over a period of two years until April 28, 2023. In the event of termination of the contractual relationship of the relevant co-founder before the end of the vesting period, MoonLake AG in first priority, or any third party designated by it, and the other shareholders in second priority pro rata to their shareholdings, had an option to purchase all or a pro rata portion of the leaver shares that remained unvested on the effective day of the termination at nominal value of CHF 0.10. Grants awarded Restricted Founder Shares Number of Shares Awards unvested as of January 1, 2023 1,110,078 Awards vested for the nine months ended September 30, 2023 (1,110,078) Awards unvested as of September 30, 2023 — Employee Share Participation Plan (ESPP) 2021-2025 - MoonLake AG The ESPP grants will vest 25% on each anniversary of the grant date. In the event of a termination of contractual relationship between the Company and the entitled employee, the awards can be deemed forfeited by MoonLake AG if certain conditions are met. Awards feature an accelerated vesting condition linked to a “Change of Control”, defined as any transfer of shares that results in the proposed acquirer holding more than 50% of the then issued share capital of MoonLake AG or the Company, as the case may be, where all the outstanding awards (whether currently outstanding or granted in the future) will be deemed fully vested. Grants awarded ESPP Number of Shares Awards issued as of January 1 and September 30, 2023 2,237,915 Awards vested as of September 30, 2023 1,525,582 Awards issued as of January 1, 2024 2,237,915 Awards forfeited for the nine months ended September 30, 2024 2 (16,853) Awards issued as of September 30, 2024 2,221,062 Awards vested as of September 30, 2024 1,827,826 As of September 30, 2024, MoonLake AG had $3.8 million of total unrecognized compensation expense related to the ESPP that will be recognized over the weighted average period of 1.30 years. Employee Stock Option Plan (ESOP) 2021-2025 - MoonLake AG The ESOP grants will vest 25% on each anniversary of the grant date. In the event of a termination of the contractual relationship between the Company and the entitled employee, options can be deemed forfeited by MoonLake AG if certain conditions are met. Awards feature an accelerated vesting condition linked to a “Change of Control”, defined as any transfer of shares that results in the proposed acquirer holding more than 50% of the then issued share capital of MoonLake AG or the Company, as the case may be, where all the outstanding awards (whether currently outstanding or granted in the future) will be deemed fully vested. Grants awarded ESOP Number of Options Awards outstanding as of January 1, 2023 466,770 Awards granted for the nine months ended September 30, 2023 133,444 Awards outstanding as of September 30, 2023 600,214 Awards exercisable as of September 30, 2023 186,593 Awards outstanding as of January 1, 2024 585,078 Awards converted from ESOP to Equity Incentive Plan for the nine months ended September 30, 2024 (486,685) Awards outstanding as of September 30, 2024 98,393 Awards exercisable as of September 30, 2024 98,393 MoonLake Immunotherapeutics 2022 Equity Incentive Plan On April 5, 2022 (the “Effective Date”), the Company created the Equity Incentive Plan to promote and closely align the interests of employees, officers, non-employee directors and other service providers of MoonLake Immunotherapeutics and its shareholders by providing share-based compensation and other performance-based compensation. The Equity Incentive Plan provides for the grant of options, stock appreciation rights, restricted stock units, restricted stock and other share-based awards and for incentive bonuses, which may be paid in cash, Common Shares or a combination thereof, as determined by the compensation committee of the board of directors or such other committee as designated by the board of directors to administer the Equity Incentive Plan. The Equity Incentive Plan shall remain available for the grant of awards until the 10th anniversary of the Effective Date. Grants awarded Equity Incentive Plan Number of Options Awards outstanding as of January 1, 2023 180,000 Awards granted for the nine months ended September 30, 2023 56,485 Awards outstanding as of September 30, 2023 236,485 Awards exercisable as of September 30, 2023 60,000 Awards outstanding as of January 1, 2024 312,400 Awards granted for the nine months ended September 30, 2024 241,820 Awards exercised for the nine months ended September 30, 2024 (17,390) Awards converted from ESOP to Equity Incentive Plan for the nine months ended September 30, 2024 486,685 Awards forfeited for the nine months ended September 30, 2024 (49,715) Awards outstanding as of September 30, 2024 973,800 Awards exercisable as of September 30, 2024 368,910 Weighted average assumptions for the awards issued during the nine months ended September 30, 2024 Estimated fair value of the option on the grant date using Black-Scholes model ($) 31.31 Exercise price ($) 45.63 Expected term of the award on the grant date (years) (1) 6 Expected volatility of the share price (2) 75% Risk-free interest rate (3) 4.3% Expected dividend rate —% (1) The expected term represents the period that share-based awards are expected to be outstanding. (2) The expected volatility was derived from the historical stock volatilities of comparable peer public companies within the Company’s industry. (3) The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the measurement date with maturities approximately equal to the expected term. As of September 30, 2024, the Company had $11.2 million of total unrecognized compensation expense related to the Equity Incentive Plan that will be recognized over the weighted average period of 1.96 years.

Income Taxes

Income Taxes	9 Months Ended
Income Taxes	Sep. 30, 2024
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company's effective tax rate (“ETR”) was 0.3% and 0.3% for the three and nine months ended September 30, 2024, respectively, and 0.2% and 0.1% for the three and nine months ended September 30, 2023, respectively. The Company is not aware of any items that would cause the quarterly ETR to be significantly different from the Company's annual ETR. The difference between the income tax provision that would be derived by applying the statutory rate to the Company's loss before income taxes and the income tax provision recorded was primarily attributable to the change in the valuation allowance. The Company continues to incur losses for the entities domiciled in the Cayman Island and Switzerland, and its ability to utilize the deferred tax asset related to the tax losses is not considered more likely than not. A full valuation allowance has been recorded against the deferred tax asset.

Commitment and Contingencies

Commitment and Contingencies	9 Months Ended
Commitment and Contingencies	Sep. 30, 2024
Commitments and Contingencies Disclosure [Abstract]
Commitment and Contingencies	Commitments and Contingencies Commitments The Company has entered into agreements as of September 30, 2024 primarily in regards to the clinical and non-clinical development services with contract research organizations ("CROs"), as well as supply and logistics services with contract manufacturing organizations ("CMOs"), for the advancement of SLK. As of September 30, 2024, the total committed expense under these agreements amounted to $145.1 million, of which $8.0 million are recognized under Prepaid expenses - current, $2.1 million are recognized under Prepaid expenses - non-current, and the rest remain unrecognized. The Company's In-License Agreement with MHKDG includes contractual milestone payments related to the achievement of pre-specified research, development, regulatory and commercialization events and indemnification provisions, which are common in such agreements. Pursuant to the agreements, the Company is obligated to make research and development and regulatory milestone payments upon the occurrence of certain events. Subject to the terms of the license, additional milestone payments of up to €299.6 million ($335.2 million using a September 30, 2024 exchange rate) are potentially payable upon satisfying specific milestones related to regulatory filing acceptance, first commercial sales, and aggregate annual net sales. The milestone payments are payable in cash. Milestone payments due prior to obtaining regulatory approval will be recorded as research and development expense upon determination that a milestone payment is probable to occur. Milestone payments due after obtaining regulatory approval will be capitalized when and if incurred. The Company will use commercially reasonable efforts to cause the milestones to occur. However, if the Company reasonably determines that a technical failure or commercial failure has occurred with respect to all or a part of the SLK Program, the Company, at its sole discretion, can terminate all or part of the SLK Program. As of September 30, 2024, the Company made a total of €7.5 million ($8.1 million using the then applicable exchange rates) in additional milestone payments. In addition, on May 12, 2023, MoonLake AG entered into an agreement with Research Cooperation Technologies, Inc. (“RCT”) and MHKDG, effective as of June 1, 2023, pursuant to which the Company was granted a royalty-bearing, nonexclusive, sublicensable right and license under RCT’s patents and know-how related to a manufacturing process using an underlying yeast strain, Pichia pastoris, to develop, manufacture, use, sell, offer for sale, and import and otherwise commercialize SLK on a world-wide basis, subject to certain restrictions. This agreement replaces the Company’s sublicense for similar rights under the In-License Agreement. In the aggregate, the Company is required to pay royalties within the range of low to mid-teen percent of net sales under the aforementioned agreements with MHKDG and RCT. Royalties will be recognized in the consolidated statements of operations and comprehensive loss when net sales are recognized.

Segment Information and Geograp

Segment Information and Geographic Data	9 Months Ended
Segment Information and Geographic Data	Sep. 30, 2024
Segment Reporting [Abstract]
Segment Information and Geographic Data	Segment Information and Geographic Data The Company operates as a single operating segment. Long-lived assets, consisting of property and equipment, net, and operating lease right-of-use assets by geographical area as of September 30, 2024 are as follows: Country September 30, 2024 December 31, 2023 Switzerland $ 680,946 $ 507,392 United Kingdom 2,012,806 2,704,555 Portugal 1,138,823 737,398 Total $ 3,832,575 $ 3,949,345

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($)	3 Months Ended		9 Months Ended
Pay vs Performance Disclosure - USD ($)	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Pay vs Performance Disclosure
Net Income (Loss)	$ (35,390,337)	$ (9,426,049)	$ (73,331,005)	$ (28,570,184)

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
Insider Trading Arrangements	Sep. 30, 2024
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Basis of Presentation and Sig_2

Basis of Presentation and Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2024
Accounting Policies [Abstract]
Basis of Presentation	The accompanying unaudited condensed consolidated financial statements include those of the Company and its subsidiaries, MoonLake Immunotherapeutics AG, a Swiss stock corporation (Aktiengesellschaft) registered with the commercial register of the Canton of Zug, Switzerland under the number CHE-433.093.536 (“MoonLake AG”), MoonLake Immunotherapeutics Ltd., a private limited company incorporated in the United Kingdom, and MNLK Immunotherapeutics, Unipessoal Lda ("MNLK PT"), a private limited company incorporated in Portugal, after elimination of all intercompany accounts and transactions. The accompanying unaudited condensed consolidated financial statements and notes hereto have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) as set forth by the Financial Accounting Standards Board (“FASB”) and in conformity with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X for interim financial reporting. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete financial statements. Any reference in these notes to applicable guidance is meant to refer to the authoritative U.S. GAAP as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Updates (“ASU”) of the FASB. In the opinion of management, all material adjustments necessary for a fair presentation of the financial information, which are of a normal and recurring nature, have been made for the interim periods reported. Results of operations for the three and nine months ended September 30, 2024 are not necessarily indicative of the results for the entire fiscal year or any other period. The unaudited condensed consolidated financial information for the three and nine months ended September 30, 2024 and 2023 have been prepared on the same basis as and should be read in conjunction with MoonLake’s audited financial statements and notes thereto for the year ended December 31, 2023 included in the Annual Report. All amounts are presented in U.S. Dollar (“$”), unless otherwise indicated. The term “Swiss franc” and “CHF” refer to the legal currency of Switzerland, "GBP" refers to the legal currency of the United Kingdom, and “€” and "Euro" refer to the legal currency of Portugal.
Use of Estimates	The preparation of financial statements in conformity with U.S. GAAP requires the Company to make judgments, estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements and the reported amounts of expenses. The significant judgments, estimates and assumptions relevant to the Company relate to: • determining whether the in-process research and development expenditure (“IPR&D”) has an alternative future use; • determining assumptions used in estimating the fair value of share-based compensation; • estimating the recoverability of the deferred tax asset; and • estimating the amount of accruals in connection with the completion of clinical trial milestones. The Company bases its judgments and estimates on various factors and information, which may include, but are not limited to, the Company’s forecasts and future plans, current economic conditions and observable market-based transactions of its own shares, the results of which form the basis for making judgments about the carrying value of assets and liabilities and recorded amounts of expenses that are not readily apparent from other sources. To the extent there are material differences between the Company’s estimates and the actual results, the Company’s future results of operation may be affected.
Cash and Cash Equivalents	The Company considers all highly liquid investments with an original maturity of three months or less at the date of purchase to be cash equivalents. Cash and cash equivalents are recorded at cost, which approximates fair value.
Marketable securities and short-term investments	The Company invests in short-term marketable securities in the form of debt securities. At the time of purchase, the Company assesses whether such debt security should be classified as held-to-maturity or available-for-sale debt securities. Debt securities are classified as held-to-maturity when the Company has the positive intent and ability to hold the securities to maturity. Held-to-maturity debt securities are carried at amortized cost, adjusted for accretion of discounts or amortization of premiums to maturity computed under the effective interest method. Such accretion or amortization is included in “Interest and dividend income”. Marketable debt securities not classified as held-to-maturity are classified as available-for-sale and reported at fair value. Net unrealized gains and losses on available-for-sale debt securities are excluded from the determination of earnings and are instead recognized in the “Accumulated other comprehensive income” component of equity until realized. Realized gains and losses on available-for-sale debt securities are computed based upon the historical cost of these securities, using the specific identification method. A decline in the fair value of any security below cost that is deemed other than temporary results in a charge to earnings and the corresponding establishment of a new cost basis for the security. Dividend and interest income are recognized when earned. Realized gains and losses are included in "Other income" and the cost of securities sold is determined using the specific-identification method. Marketable debt securities are classified as either “Cash and cash equivalents” or “Short‑term marketable debt securities” according to their original maturity at the time of acquisition. Changes in unrealized gains and losses pertaining to cash equivalent securities are added back into the consolidated statements of cash flows as those are excluded from the determination of earnings but impact the cash and cash equivalents position.
Concentration of Credit Risk	Financial instruments that potentially subject the Company to concentration of credit risk consist of cash accounts in large financial institutions which, at times, may exceed the CHF 100,000 deposit protection limit in Switzerland, the $250,000 Federal Deposit Insurance Corporation deposit insurance coverage limit in the United States, the GBP 85,000 Financial Services Compensation Scheme deposit protection limit in the United Kingdom, or the €100,000 Fundo de Garantia de Depósitos deposit protection limit in Portugal. The Company believes it is not exposed to significant credit risk due to the financial strength of the depository institutions in which the cash and cash equivalents are held. Additionally, the Company ensures further protection against credit risk by diversifying its cash holdings across a variety of credit institutions, thereby minimizing the potential impact of any adverse events on a single institution. Further, the Company's investment strategy for cash (in excess of current business requirements) is set to invest in short-term marketable debt securities. Management actively monitors credit risk in the investment portfolio. Credit risk exposures are controlled in accordance with policies approved by the board of directors to identify, measure, monitor and control credit risks.
Fair Value Measurements	The Company follows the guidance included in ASC 820, Fair Value Measurement . Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. There are three levels of inputs to fair value measurements: • Level 1, meaning the use of quoted prices for identical instruments in active markets; • Level 2, meaning the use of quoted prices for similar instruments in active markets or quoted prices for identical or similar instruments in markets that are not active or are directly or indirectly observable; and • Level 3, meaning the use of unobservable inputs. Observable market data is used when available.
Segment Information	The Company operates as a single operating segment. The Company’s chief operating decision maker, its Chief Executive Officer, manages the Company’s operations on a stand-alone basis for the purposes of allocating resources and assessing financial performance.
Property and Equipment	Property and equipment, net is stated at cost, net of accumulated depreciation. Depreciation is computed using the straight-line method based on the estimated useful lives of three
Research and Development Contract Costs and Accruals	Research and development expenses include employee payroll, consulting, contract research and contract manufacturing costs attributable to research and development activities and are expensed as incurred. Upfront payments and milestone payments made for the licensing of technology are expensed as research and development expenses in the period in which it is probable that a liability has been incurred. Advance payments for goods or services to be received in the future for use in research and development activities are recorded as prepaid expenses. The prepaid amounts are expensed as the related goods are delivered or the services are performed. The Company has entered into various research and development contracts with companies both inside and outside of the United States. These agreements are generally cancellable, and related payments are recorded as research and development expenses as incurred. The Company records accruals for estimated ongoing research costs. When evaluating the adequacy of the accrued liabilities, the Company analyzes progress of the studies or trials, including the phase or completion of events, invoices received and contracted costs. Significant judgments and estimates are made in determining the accrued balances at the end of any reporting period. Actual results could differ from the Company’s estimates. The Company’s historical accrual estimates have not been materially different from the actual costs.
Share-Based Compensation	Share-Based Compensation The Company recognizes compensation expense based on estimated fair values for all stock-based payment awards made to eligible employees, members of the board of directors and independent contractors that are expected to vest. The valuation of stock option awards is determined at the date of grant using the Black-Scholes option pricing model. The Black-Scholes option pricing model requires the Company to make assumptions and judgements about the inputs used in the calculations, such as the fair value of the common stock, expected term, expected volatility of the Company’s common stock, risk-free interest rate and expected dividend yield. The valuation of restricted stock awards is measured by the fair value of the Company’s common stock on the date of the grant. Share-based compensation ) has historically been estimated by management with reference to the market-based transaction with its Series A investors, as there was no public market for the common stock. Share-based payment arrangements are accounted for under the fair value method. Total compensation is measured at grant date, based on the fair value of the award at that date, and recorded in earnings over the period the employees are required to render service. The Company recognizes compensation cost only for those awards expected to meet the service conditions on a straight-line basis over the requisite service period of the award.
Foreign Currency	The functional currency of the Company and its subsidiaries is the U.S. dollar. Balances and transactions denominated in foreign currencies are converted as follows: monetary assets and liabilities are translated using exchange rates in effect at the balance sheet dates and non-monetary assets and liabilities are translated at historical exchange rates. Revenue and expenses are translated at the daily exchange rate on the respective accounting date.
Income Taxes	The Company accounts for income taxes by using the asset and liability method of accounting for income taxes. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. A valuation allowance is recorded to the extent it is more likely than not that all or a portion of the Company's deferred tax assets will not be realized. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in operations in the period that includes the enactment date.
Net Loss per Class A Ordinary Shares	Basic net loss per Class A Ordinary Share is calculated using the two-class method under which earnings are allocated to both Class A Ordinary Shares and participating securities. Basic net loss per share is calculated by dividing the net loss attributable to Class A Ordinary Shares by the weighted-average number of Class A Ordinary Shares outstanding for the period. The diluted net loss per Class A Ordinary Share is computed by dividing the net loss using the weighted-average number of Class A Ordinary Shares and, if dilutive, potential Class A Ordinary Shares outstanding during the period.
Acquisitions	The Company evaluates acquisitions of assets and other similar transactions to assess whether or not the transaction should be accounted for as a business combination or asset acquisition by first assessing whether substantially all of the fair value of the gross assets acquired is concentrated in a single identifiable asset or group of similar identifiable assets. On April 29, 2021, MoonLake AG entered into an in-licensing agreement (the “In-License Agreement”) with Merck Healthcare KGaA, Darmstadt, Germany (“MHKDG”) to acquire the Sonelokimab program (the “SLK Program”) and determined that substantially all of the fair value of the gross assets acquired related to IPR&D of SLK. Therefore, this transaction was accounted for as an asset acquisition. IPR&D represents incomplete technologies that the Company acquires, which at the time of acquisition, are still under development and have no alternative future use. The fair value of such technologies is expensed upon acquisition. A technology is considered to have an alternative future use if it is probable that the Company will use the asset in its current, incomplete state as it existed at the acquisition date, in another research and development project that has not yet commenced, and economic benefit is anticipated from that use. If a technology is determined to have an alternative future use, then the fair value of the program would be recorded as an asset on the balance sheet rather than expensed. Contingent consideration payments (for example milestone payments due upon the occurrence of a specific event) in asset acquisitions are recognized in the period in which it is probable that a liability has been incurred (unless the contingent consideration meets the definition of a derivative, in which case the amount becomes part of the cost in the asset acquired). Upon recognition of the contingent consideration payment, the amount is expensed if it relates to IPR&D or capitalized if it relates to a developed product which is generally considered to be when clinical trials have been completed and regulatory approval obtained. Future royalty payments due on net sales will be recognized in cost of goods sold when net sales are recognized.
Pension Accounting	The Company accounts for pension assets and liabilities in accordance with ASC 715, Compensation – Retirement Benefits , which requires the recognition of the funded status of pension plans in the Company’s consolidated balance sheet. The liability in respect to defined benefit pension plans is the projected benefit obligation calculated annually by independent actuaries using the projected unit credit method. The projected benefit obligation as of September 30, 2024 represents the actuarial present value of the estimated future payments required to settle the obligation that is attributable to employee services rendered before that date. Service costs for such pension plans, represented in the net periodic pension benefit cost, are included in the personnel expenses of the various functions where the employees are engaged. The other components of net benefit cost are included in the consolidated statements of operations and comprehensive loss separately from the service cost component, in “other income, net.” Plan assets are recorded at their fair value.
Leases	The Company determines if an arrangement is or contains a lease at contract inception. For these arrangements, it is evaluated if the arrangement involves an identified asset that is physically distinct or whether the Company has the right to substantially all of the capacity of an identified asset that is not physically distinct. In arrangements that involve an identified asset, there is also judgment in evaluating if the Company has the right to direct the use of that asset. MoonLake does not have any finance leases. As of September 30, 2024, the Company has five operating leases related to the office spaces located in (i) Dorfstrasse 29, 6300, Zug, Switzerland (comprised of two leases), (ii) 95 Regent Street, CB2 1AW, Cambridge, England, United Kingdom, and (iii) Rua Manuel Pinto de Azedevo 860, 4150-335, Porto, Portugal (comprised of two leases). The operating leases are recognized on a straight-line basis over the lease term commencing on the date the Company has the right to use the leased property. Right-of-use assets and lease liabilities are measured at the lease commencement date based on the present value of the remaining lease payments over the lease term, determined using the discount rate for the lease at the commencement date. Because the rate implicit in the leases is not readily determinable, the Company uses the incremental borrowing rate as the discount rate, which approximates the interest rate at which the Company could borrow on a collateralized basis with similar terms and payments and in similar economic environments. Leases with an initial term of 12 months or less that do not have the option to purchase the underlying asset are not recorded on the balance sheet, with lease expense for these leases recognized on a straight-line basis over the lease term commencing on the date the Company has the right to use the leased property.
Recently Issued Accounting Pronouncements not yet Adopted	In November 2023, the FASB issued ASU 2023-07, Segment reporting — Improvements to Reportable Segment Disclosures. This new standard requires public entities to disclose significant segment expenses and additional segment items annually and to provide all reported segment profit or loss and assets disclosures currently required annually on an interim basis. The standard also requires disclosure of the Chief Operating Decision Maker's title and position. The standard does not change the manner in which public entities identify their operating segments, aggregate them, or apply the quantitative thresholds for determining their reportable segments. It is effective for fiscal years beginning after December 15, 2023 and interim periods in fiscal years beginning after December 15, 2024, with early adoption permitted. The Company has determined it operates as a single segment, therefore, we do not anticipate this ASU to materially impact our consolidated financial statements and related disclosures. In December 2023, the FASB issued ASU 2023-09, Income taxes — Improvements to Income Taxes Disclosure. The purpose of this guidance is to enhance the transparency and usefulness of income tax disclosures and provide comprehensive income tax information, particularly in relation to rate reconciliation and income taxes paid in the U.S and foreign jurisdictions. It is effective for fiscal years beginning after December 15, 2024 and interim periods in fiscal years beginning after December 15, 2024, with early adoption permitted. This ASU will result in the required additional disclosures being included in our consolidated financial statements, once adopted.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
Fair Value Measurements (Tables)	Sep. 30, 2024
Fair Value Disclosures [Abstract]
Schedule of debt securities by level within the fair value hierarchy	The following table presents information about the Company's short-term marketable debt securities measured at fair value on a recurring basis and indicate the level in the fair value hierarchy in which the Company classifies the fair value measurement: September 30, 2024 December 31, 2023 Level 2 Total Level 2 Total Eurocommercial Papers $ 89,072,100 $ 89,072,100 $ 109,608,915 $ 109,608,915 Certificates of Deposit 88,991,100 88,991,100 79,626,727 79,626,727 Total $ 178,063,200 $ 178,063,200 $ 189,235,642 $ 189,235,642

Investments (Tables)

Investments (Tables)	9 Months Ended
Investments (Tables)	Sep. 30, 2024
Investments, Debt and Equity Securities [Abstract]
Schedule of investments in short-term marketable debt securities	The fair value and amortized cost of investments in short-term marketable debt securities by major security type as of September 30, 2024 are as follows: Amortized cost Gross unrealized gains Gross unrealized losses Fair value Eurocommercial Papers $ 87,231,307 $ 1,840,793 $ — $ 89,072,100 Certificates of Deposit 87,602,179 1,388,921 — 88,991,100 Total $ 174,833,486 $ 3,229,714 $ — $ 178,063,200 Of which classified within cash and cash equivalents 59,212,123 582,677 — 59,794,800 Of which classified within short-term marketable debt securities 115,621,363 2,647,037 — 118,268,400
Schedule of fair value changes of marketable securities	The following table presents the changes in fair values of the Company’s short-term marketable debt securities, classified as Level 2 financial assets, and recognized in accumulated other comprehensive income: Beginning balance, January 1, 2024 $ 2,720,854 Other comprehensive income before reclassifications 13,000,645 Amounts reclassified from accumulated other comprehensive income (12,491,785) Ending balance, September 30, 2024 $ 3,229,714

Prepaid Expenses (Tables)

Prepaid Expenses (Tables)	9 Months Ended
Prepaid Expenses (Tables)	Sep. 30, 2024
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Schedule of prepaid expenses	Prepaid expenses - current September 30, 2024 December 31, 2023 Non-clinical research and clinical development services $ 7,381,811 $ 842,729 Supply and manufacturing services 6,358,892 1,205 Insurance 1,496,521 1,077,478 Other prepayments 747,201 180,791 Total $ 15,984,425 $ 2,102,203 Prepaid expenses - non-current September 30, 2024 December 31, 2023 Supply and manufacturing services $ 2,064,575 $ 8,423,468 Total $ 2,064,575 $ 8,423,468

Trade and Other Payables (Table

Trade and Other Payables (Tables)	9 Months Ended
Trade and Other Payables (Tables)	Sep. 30, 2024
Payables and Accruals [Abstract]
Trade and other payables, current	September 30, 2024 December 31, 2023 Research and development services and license fees $ 7,113,098 $ 911,454 Supply and manufacturing fees payable 3,044,237 553,459 Consulting and advisory services 307,581 80,695 Legal advisory fees payable 104,317 47,095 Other payables 141,370 244,981 Total $ 10,710,603 $ 1,837,684

Accrued Expenses and Other Cu_2

Accrued Expenses and Other Current Liabilities (Tables)	9 Months Ended
Accrued Expenses and Other Current Liabilities (Tables)	Sep. 30, 2024
Payables and Accruals [Abstract]
Schedule of accrued expenses and other current liabilities	September 30, 2024 December 31, 2023 Research and development services and license fees $ 3,253,581 $ 1,226,281 Bonuses and related employees compensation expenses 2,922,982 2,780,219 Supply and manufacturing services 894,894 1,603,739 Tax liabilities 484,482 367,976 Consultant and other fees 351,774 853,905 Legal fees 17,811 98,000 Total $ 7,925,524 $ 6,930,120

Leases (Tables)

Leases (Tables)	9 Months Ended
Leases (Tables)	Sep. 30, 2024
Leases [Abstract]
Lease, Cost	The weighted average remaining lease term and weighted average discount rate for the operating leases as of September 30, 2024 and December 31, 2023 were as follows: September 30, 2024 December 31, 2023 Weighted average remaining lease term (in months) 32 39 Weighted average discount rate 4.7 % 4.9 % The Company recorded the following lease and variable lease expenses for the three and nine months ended September 30, 2024 and September 30, 2023: Three Months Ended September 30, 2024 Three Months Ended September 30, 2023 Nine Months Ended September 30, 2024 Nine Months Ended September 30, 2023 Operating lease expense $ 358,583 $ 39,562 $ 1,061,029 $ 117,832 Variable lease expense 1 5,398 — 5,398 — Total lease expense $ 363,981 $ 39,562 $ 1,066,427 $ 117,832
Schedule of Future Lease Payments	The maturities of the Company's operating lease liabilities as of September 30, 2024 are as follows: Year ending December 31, Amount Remainder of fiscal 2024 $ 386,519 2025 1,571,589 2026 1,242,550 2027 140,313 2028 140,313 Thereafter 95,627 Total lease payments 3,576,911 Less imputed interest (196,309) Total lease liability 3,380,602 Less current portion of lease liability (1,444,893) Long-term portion operating lease liability $ 1,935,709

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	9 Months Ended
Employee Benefit Plans (Tables)	Sep. 30, 2024
Retirement Benefits [Abstract]
Components of net periodic benefit cost under the plan	Components of Net Periodic Benefit Cost under the Plan Three Months Ended September 30, 2024 Three Months Ended September 30, 2023 Nine Months Ended September 30, 2024 Nine Months Ended September 30, 2023 Service cost $ 71,107 $ 31,175 $ 210,387 $ 91,596 Interest cost 8,387 7,784 24,814 22,872 Expected return on plan assets (15,338) (9,280) (45,380) (27,265) Amortization of unrecognized loss 2,609 — 7,717 — Prior service credit recognized in current year (2,582) — (7,639) — Total net periodic benefit cost $ 64,183 $ 29,679 $ 189,899 $ 87,203

Shareholders_ Equity (Tables)

Shareholders’ Equity (Tables)	9 Months Ended
Shareholders’ Equity (Tables)	Sep. 30, 2024
Equity [Abstract]
Schedule of stock authorized and issued	Class A Ordinary Shares (1) Class C Ordinary Shares (1) Total Number of Ordinary Shares Authorized Issued Authorized Issued Authorized Issued and Outstanding Balance at January 1, 2024 500,000,000 60,466,453 100,000,000 2,505,476 600,000,000 62,971,929 Conversion of Class C Ordinary Shares into Class A Ordinary Shares — 1,493,356 — (1,493,356) — — Issuance of Class A Ordinary Shares under the ATM facility — 914,828 — — — 914,828 Cancellation of Class C shares following an employee contract termination in MoonLake AG — — — (16,853) — (16,853) Balance at March 31, 2024 500,000,000 62,874,637 100,000,000 995,267 600,000,000 63,869,904 Balance at June 30, 2024 500,000,000 62,874,637 100,000,000 995,267 600,000,000 63,869,904 Conversion of Class C Ordinary Shares into Class A Ordinary Shares — 153,998 — (153,998) — — Options exercised under the Equity Incentive Plan — 17,390 — — — 17,390 Balance at September 30, 2024 500,000,000 63,046,025 100,000,000 841,269 600,000,000 63,887,294 (1)

Net Loss per Share (Tables)

Net Loss per Share (Tables)	9 Months Ended
Net Loss per Share (Tables)	Sep. 30, 2024
Earnings Per Share [Abstract]
Schedule of earnings per share, basic and diluted	The following table sets forth the loss per share calculations for the three and nine months ended September 30, 2024 compared to the three and nine months ended September 30, 2023: Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Numerator Net loss attributable to controlling interests shareholders $ (35,390,337) $ (9,426,049) $ (73,331,005) $ (28,570,184) Denominator Total weighted average number of outstanding shares 62,896,782 53,517,655 62,803,220 45,485,650 Net loss per share – basic and diluted $ (0.56) $ (0.18) $ (1.17) $ (0.63)

Share-Based Compensation (Table

Share-Based Compensation (Tables)	9 Months Ended
Share-Based Compensation (Tables)	Sep. 30, 2024
Share-Based Payment Arrangement [Abstract]
Schedule of share-based compensation expense driven by share-based compensation plans and programs	The share-based compensation expense was driven by the aforementioned two main active share-based compensation plans and programs: Compensation Plan Three Months Ended September 30, 2024 Three Months Ended September 30, 2023 Nine Months Ended September 30, 2024 Nine Months Ended September 30, 2023 MoonLake AG Restricted Founder Shares $ — $ — $ — $ 1,574,299 ESPP 741,154 762,309 2,191,557 2,590,576 ESOP — 255,171 — 614,469 Equity Incentive Plan 1,101,455 408,171 3,156,505 721,155 Total share-based compensation expense $ 1,842,609 $ 1,425,651 $ 5,348,062 $ 5,500,499 Of which: included in research and development expense 508,697 262,717 1,446,049 1,150,815 Of which: included in general and administrative expense 1,333,912 1,162,934 3,902,013 4,349,684
Summary of nonvested restricted stock shares activity	Grants awarded Restricted Founder Shares Number of Shares Awards unvested as of January 1, 2023 1,110,078 Awards vested for the nine months ended September 30, 2023 (1,110,078) Awards unvested as of September 30, 2023 —
Schedule of nonvested share activity	Grants awarded ESPP Number of Shares Awards issued as of January 1 and September 30, 2023 2,237,915 Awards vested as of September 30, 2023 1,525,582 Awards issued as of January 1, 2024 2,237,915 Awards forfeited for the nine months ended September 30, 2024 2 (16,853) Awards issued as of September 30, 2024 2,221,062 Awards vested as of September 30, 2024 1,827,826
Summary of weighted average assumptions for awards issued	Weighted average assumptions for the awards issued during the nine months ended September 30, 2024 Estimated fair value of the option on the grant date using Black-Scholes model ($) 31.31 Exercise price ($) 45.63 Expected term of the award on the grant date (years) (1) 6 Expected volatility of the share price (2) 75% Risk-free interest rate (3) 4.3% Expected dividend rate —% (1) The expected term represents the period that share-based awards are expected to be outstanding. (2) The expected volatility was derived from the historical stock volatilities of comparable peer public companies within the Company’s industry. (3) The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the measurement date with maturities approximately equal to the expected term.
Schedule of option activity for share-based payment arrangement	Grants awarded ESOP Number of Options Awards outstanding as of January 1, 2023 466,770 Awards granted for the nine months ended September 30, 2023 133,444 Awards outstanding as of September 30, 2023 600,214 Awards exercisable as of September 30, 2023 186,593 Awards outstanding as of January 1, 2024 585,078 Awards converted from ESOP to Equity Incentive Plan for the nine months ended September 30, 2024 (486,685) Awards outstanding as of September 30, 2024 98,393 Awards exercisable as of September 30, 2024 98,393 Grants awarded Equity Incentive Plan Number of Options Awards outstanding as of January 1, 2023 180,000 Awards granted for the nine months ended September 30, 2023 56,485 Awards outstanding as of September 30, 2023 236,485 Awards exercisable as of September 30, 2023 60,000 Awards outstanding as of January 1, 2024 312,400 Awards granted for the nine months ended September 30, 2024 241,820 Awards exercised for the nine months ended September 30, 2024 (17,390) Awards converted from ESOP to Equity Incentive Plan for the nine months ended September 30, 2024 486,685 Awards forfeited for the nine months ended September 30, 2024 (49,715) Awards outstanding as of September 30, 2024 973,800 Awards exercisable as of September 30, 2024 368,910

Segment Information and Geogr_2

Segment Information and Geographic Data (Tables)	9 Months Ended
Segment Information and Geographic Data (Tables)	Sep. 30, 2024
Segment Reporting [Abstract]
Long-Lived Assets by Geographic Areas	Long-lived assets, consisting of property and equipment, net, and operating lease right-of-use assets by geographical area as of September 30, 2024 are as follows: Country September 30, 2024 December 31, 2023 Switzerland $ 680,946 $ 507,392 United Kingdom 2,012,806 2,704,555 Portugal 1,138,823 737,398 Total $ 3,832,575 $ 3,949,345

Basis of Presentation and Sig_3

Basis of Presentation and Significant Accounting Policies (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2024 USD ($) lease_contract	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($) segment lease_contract lease	Sep. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)
Class of Stock [Line Items]
Cash and cash equivalents	$ 375,656,291		$ 375,656,291		$ 451,169,337
Foreign currency transaction gain (loss), realized	$ (26,746)	$ (557,144)	$ (125,581)	$ (276,491)
Number of operating leases \| lease			5
Number of lease contracts \| lease_contract	2		2
Number of operating segments \| segment			1
Commercial Paper and Certificates of Deposit
Class of Stock [Line Items]
Cash and cash equivalents	$ 59,800,000		$ 59,800,000		$ 129,400,000
Minimum
Class of Stock [Line Items]
Property and equipment, useful life	3 years		3 years
Maximum
Class of Stock [Line Items]
Property and equipment, useful life	5 years		5 years

Risks and Liquidity (Details)

Risks and Liquidity (Details) - USD ($)	3 Months Ended						9 Months Ended
Risks and Liquidity (Details) - USD ($)	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2024	Sep. 30, 2023
Risks and Uncertainties [Abstract]
Net loss	$ (36,114,424)	$ (24,758,754)	$ (13,975,521)	$ (11,619,353)	$ (12,353,387)	$ (12,218,987)	$ (74,848,699)	$ (36,191,727)
Excess of current assets less current liabilities	492,200,000						492,200,000
Unrestricted cash	$ 375,700,000						$ 375,700,000

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($)	Sep. 30, 2024	Dec. 31, 2023
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]
Short-term marketable debt securities	$ 118,268,400	$ 59,838,900
Fair Value, Recurring
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]
Total	178,063,200	189,235,642
Eurocommercial Papers \| Fair Value, Recurring
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]
Short-term marketable debt securities	89,072,100	109,608,915
Certificates of Deposit \| Fair Value, Recurring
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]
Short-term marketable debt securities	88,991,100	79,626,727
Level 2 \| Fair Value, Recurring
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]
Total	178,063,200	189,235,642
Level 2 \| Eurocommercial Papers \| Fair Value, Recurring
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]
Short-term marketable debt securities	89,072,100	109,608,915
Level 2 \| Certificates of Deposit \| Fair Value, Recurring
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]
Short-term marketable debt securities	$ 88,991,100	$ 79,626,727

Investments - Schedule of Fair

Investments - Schedule of Fair Value and Amortized Cost of Investments in Short-Term Marketable Debt (Details)	Sep. 30, 2024 USD ($)
Debt Securities, Available-for-Sale [Line Items]
Amortized cost	$ 174,833,486
Gross unrealized gains	3,229,714
Gross unrealized losses	0
Fair value	178,063,200
Cash and Cash Equivalents
Debt Securities, Available-for-Sale [Line Items]
Amortized cost	59,212,123
Gross unrealized gains	582,677
Gross unrealized losses	0
Fair value	59,794,800
Debt Securities
Debt Securities, Available-for-Sale [Line Items]
Amortized cost	115,621,363
Gross unrealized gains	2,647,037
Gross unrealized losses	0
Fair value	118,268,400
Eurocommercial Papers
Debt Securities, Available-for-Sale [Line Items]
Amortized cost	87,231,307
Gross unrealized gains	1,840,793
Gross unrealized losses	0
Fair value	89,072,100
Certificates of Deposit
Debt Securities, Available-for-Sale [Line Items]
Amortized cost	87,602,179
Gross unrealized gains	1,388,921
Gross unrealized losses	0
Fair value	$ 88,991,100

Investments - Schedule of Chang

Investments - Schedule of Changes in Fair Value of Short-Term Marketable Securities (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain (Loss) [Roll Forward]
Other comprehensive income before reclassifications	$ 325,510	$ (3,437,291)	$ (508,860)	$ (3,046,538)
Level 2
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain (Loss) [Roll Forward]
Gross unrealized gain (loss), beginning balance			2,720,854
Other comprehensive income before reclassifications			13,000,645
Amounts reclassified from accumulated other comprehensive income			(12,491,785)
Gross unrealized gain (loss), ending balance	$ 3,229,714		$ 3,229,714

Prepaid Expenses (Details)

Prepaid Expenses (Details) - USD ($)	Sep. 30, 2024	Dec. 31, 2023
Prepaid expenses - current
Non-clinical research and clinical development services	$ 7,381,811	$ 842,729
Supply and manufacturing services	6,358,892	1,205
Insurance	1,496,521	1,077,478
Other prepayments	747,201	180,791
Total	15,984,425	2,102,203
Prepaid expenses - non-current
Supply and manufacturing services	2,064,575	8,423,468
Total	$ 2,064,575	$ 8,423,468

Trade and Other Payables (Detai

Trade and Other Payables (Details) - USD ($)	Sep. 30, 2024	Dec. 31, 2023
Payables and Accruals [Abstract]
Research and development services and license fees	$ 7,113,098	$ 911,454
Supply and manufacturing fees payable	3,044,237	553,459
Consulting and advisory services	307,581	80,695
Legal advisory fees payable	104,317	47,095
Other payables	141,370	244,981
Total	$ 10,710,603	$ 1,837,684

Accrued Expenses and Other Cu_3

Accrued Expenses and Other Current Liabilities (Details) - USD ($)	Sep. 30, 2024	Dec. 31, 2023
Payables and Accruals [Abstract]
Research and development services and license fees	$ 3,253,581	$ 1,226,281
Bonuses and related employees compensation expenses	2,922,982	2,780,219
Supply and manufacturing services	894,894	1,603,739
Tax liabilities	484,482	367,976
Consultant and other fees	351,774	853,905
Legal fees	17,811	98,000
Total	$ 7,925,524	$ 6,930,120

Leases - Additional Information

Leases - Additional Information (Details)					1 Months Ended	9 Months Ended
Leases - Additional Information (Details)	Aug. 14, 2024 ft² period	Dec. 12, 2023 ft²	Oct. 13, 2023 ft²	Oct. 09, 2023 ft² period	Aug. 31, 2021 ft²	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Dec. 31, 2023
Lessee, Lease, Description [Line Items]
Lessee, operating lease, number of renewal options \| period	2			2
Operating lease, payments \| $						$ 1,101,661	$ 78,270
Switzerland Office
Lessee, Lease, Description [Line Items]
Square foot of leased space (in square feet)					2,300
Lessee, operating lease, term of contract		3 years			3 years			3 years
Operating lease, additional area of leased space		1,700
Porto Office
Lessee, Lease, Description [Line Items]
Square foot of leased space (in square feet)	2,000			3,900
Lessee, operating lease, renewal term	3 years			3 years
Porto Office \| Building
Lessee, Lease, Description [Line Items]
Lessee, operating lease, term of contract	2 years			3 years
Cambridge Office
Lessee, Lease, Description [Line Items]
Square foot of leased space (in square feet)			6,000
Cambridge Office \| Building
Lessee, Lease, Description [Line Items]
Lessee, operating lease, term of contract			3 years

Leases - Weighted Average Remai

Leases - Weighted Average Remaining Lease Term and Discount Rate (Details)	Sep. 30, 2024	Dec. 31, 2023
Leases [Abstract]
Weighted average remaining lease term (in months)	32 months	39 months
Weighted average discount rate	4.70%	4.90%

Leases - Future Lease Payments

Leases - Future Lease Payments (Details) - USD ($)	Sep. 30, 2024	Dec. 31, 2023
Leases [Abstract]
Remainder of fiscal 2024	$ 386,519
2025	1,571,589
2026	1,242,550
2027	140,313
2028	140,313
Thereafter	95,627
Total lease payments	3,576,911
Less imputed interest	(196,309)
Total lease liability	3,380,602
Less current portion of lease liability	(1,444,893)	$ (1,197,876)
Long-term portion of operating lease liabilities	$ 1,935,709	$ 2,499,990

Leases - Total Lease Expense (D

Leases - Total Lease Expense (Details) - USD ($)	3 Months Ended		9 Months Ended
Leases - Total Lease Expense (Details) - USD ($)	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Leases [Abstract]
Operating lease expense	$ 358,583	$ 39,562	$ 1,061,029	$ 117,832
Variable lease expense	5,398	0	5,398	0
Total lease expense	$ 363,981	$ 39,562	$ 1,066,427	$ 117,832

Employee Benefit Plans (Details

Employee Benefit Plans (Details) - USD ($)	3 Months Ended		9 Months Ended
Employee Benefit Plans (Details) - USD ($)	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Retirement Benefits [Abstract]
Service cost	$ 71,107	$ 31,175	$ 210,387	$ 91,596
Interest cost	8,387	7,784	24,814	22,872
Expected return on plan assets	(15,338)	(9,280)	(45,380)	(27,265)
Amortization of unrecognized loss	2,609	0	7,717	0
Prior service credit recognized in current year	(2,582)	0	(7,639)	0
Total net periodic benefit cost	$ 64,183	$ 29,679	$ 189,899	$ 87,203

Employee Benefit Plans - Narrat

Employee Benefit Plans - Narrative (Details)	3 Months Ended		9 Months Ended
Employee Benefit Plans - Narrative (Details)	Dec. 31, 2024 USD ($)	Dec. 31, 2024 CHF (SFr)	Sep. 30, 2024 USD ($)	Sep. 30, 2024 CHF (SFr)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contributions made to plan			$ 192,563	SFr 169,455
Forecast
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contributions made to plan	$ 256,751	SFr 225,940
Defined contribution plan, increase (decrease), cost	$ 64,188	SFr 56,485

Shareholders_ Equity - Schedule

Shareholders’ Equity - Schedule of Stock Authorized and Issued (Details) - $ / shares	1 Months Ended	3 Months Ended					9 Months Ended
	Sep. 25, 2024	Sep. 30, 2024	Mar. 31, 2024	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2024	Dec. 31, 2023
Common Shares
Stock options exercised (in shares)		17,390
Issuance of shares under the ATM facility (in shares)			914,828
Cancellation of Class C shares following an employee contract termination in MoonLake AG (in shares)			16,853
Total Number of Ordinary Shares
Authorized, beginning balance (in shares)		600,000,000	600,000,000				600,000,000
Shares issued, beginning balance (in shares)		63,869,904	62,971,929				62,971,929
Number of shares issued (in shares)			914,828
Cancellation of Class C shares following an employee contract termination in MoonLake AG (in shares)			16,853
Authorized, ending balance (in shares)		600,000,000	600,000,000				600,000,000
Shares issued, ending balance (in shares)		63,887,294	63,869,904				63,887,294
Common Class A
Common Shares
Authorized, beginning balance (in shares)			500,000,000				500,000,000
Issued, beginning balance (in shares)			60,466,453				60,466,453
Authorized, ending balance (in shares)		500,000,000					500,000,000
Issued, ending balance (in shares)		63,046,025					63,046,025
Total Number of Ordinary Shares
Common stock, par value (CHF/USD per share)		$ 0.0001					$ 0.0001	$ 0.0001
Common Class C
Common Shares
Authorized, beginning balance (in shares)			100,000,000				100,000,000
Issued, beginning balance (in shares)			2,505,476				2,505,476
Authorized, ending balance (in shares)		100,000,000					100,000,000
Issued, ending balance (in shares)		841,269					841,269
Total Number of Ordinary Shares
Common stock, par value (CHF/USD per share)		$ 0.0001					$ 0.0001	$ 0.0001
Common Stock \| Common Class A
Common Shares
Authorized, beginning balance (in shares)		500,000,000	500,000,000				500,000,000
Issued, beginning balance (in shares)		62,874,637	60,466,453				60,466,453
Conversion of Class C Ordinary Shares into Class A Ordinary Shares (in shares)	153,998	153,998	1,493,356	74,678	4,587,713	176,603
Stock options exercised (in shares)		17,390
Issuance of shares under the ATM facility (in shares)			914,828		9,744,894
Authorized, ending balance (in shares)		500,000,000	500,000,000				500,000,000
Issued, ending balance (in shares)		63,046,025	62,874,637				63,046,025
Total Number of Ordinary Shares
Number of shares issued (in shares)			914,828		9,744,894
Common stock, par value (CHF/USD per share)		$ 0.0001					$ 0.0001
Common Stock \| Common Class A \| Conversion Of Class C into Class A
Common Shares
Conversion of Class C Ordinary Shares into Class A Ordinary Shares (in shares)		153,998	1,493,356
Common Stock \| Common Class C
Common Shares
Authorized, beginning balance (in shares)		100,000,000	100,000,000				100,000,000
Issued, beginning balance (in shares)		995,267	2,505,476				2,505,476
Conversion of Class C Ordinary Shares into Class A Ordinary Shares (in shares)	153,998	(153,998)	(1,493,356)	(74,678)	(4,587,713)	(176,603)
Cancellation of Class C shares following an employee contract termination in MoonLake AG (in shares)			16,853
Authorized, ending balance (in shares)		100,000,000	100,000,000				100,000,000
Issued, ending balance (in shares)		841,269	995,267				841,269
Total Number of Ordinary Shares
Cancellation of Class C shares following an employee contract termination in MoonLake AG (in shares)			16,853
Common stock, par value (CHF/USD per share)		$ 0.0001					$ 0.0001
Common Stock \| Common Class C \| Conversion Of Class C into Class A
Common Shares
Conversion of Class C Ordinary Shares into Class A Ordinary Shares (in shares)		(153,998)	(1,493,356)

Shareholders_ Equity - Narrativ

Shareholders’ Equity - Narrative (Details)						1 Months Ended	3 Months Ended						9 Months Ended
Shareholders’ Equity - Narrative (Details)	Mar. 08, 2024 USD ($) shares	Jul. 10, 2023 USD ($)	Jul. 09, 2023 USD ($) shares	Jun. 30, 2023 USD ($) shares	Jun. 27, 2023 USD ($) $ / shares shares	Sep. 25, 2024 shares	Sep. 30, 2024 USD ($) vote $ / shares shares	Jun. 30, 2024 USD ($) shares	Mar. 31, 2024 USD ($) $ / shares shares	Sep. 30, 2023 shares	Jun. 30, 2023 shares	Mar. 31, 2023 shares	Sep. 30, 2024 vote $ / shares shares	Dec. 31, 2023 $ / shares shares	Aug. 31, 2023 USD ($)	May 11, 2023 USD ($)	Dec. 31, 2022 shares	Apr. 28, 2021 shares
Class of Stock [Line Items]
Sale of stock, stamp duty tax \| $	$ 1,600,000	$ 2,800,000
Stock options exercised (in shares)							17,390
Common stock, conversion ratio (in shares)							33.638698						33.638698
May 2023 Sales Agreement \| ATM Shares
Class of Stock [Line Items]
Sale of stock, authorized amount (in shares) \| $																$ 200,000,000
Sale of stock, remaining authorized repurchase amount \| $					$ 0
May 2023 And August 2023 Sales Agreement \| ATM Shares
Class of Stock [Line Items]
Sale of stock, authorized amount (in shares) \| $															$ 350,000,000
Equity Incentive Plan
Class of Stock [Line Items]
Stock options exercised (in shares)							17,390						17,390
MoonLake AG
Class of Stock [Line Items]
Common shares, shares outstanding (in shares)																		110,000
MoonLake AG \| MoonLake Immunotherapeutics
Class of Stock [Line Items]
Net proceeds from the business combination \| $	800,000		$ 38,900,000
Proceeds from contributions from parent \| $	$ 150,000,000	$ 275,000,000
Underwriting Agreement
Class of Stock [Line Items]
Sale of stock (in shares)					8,000,000
Issuance price per share (USD per share) \| $ / shares					$ 50
Net proceeds from the business combination \| $				$ 436,700,000
Payments of stock issuance costs \| $				$ 23,300,000
Underwriting Agreement \| MoonLake AG \| MoonLake Immunotherapeutics
Class of Stock [Line Items]
Sale of stock (in shares)	501		22,756
Over-Allotment Option
Class of Stock [Line Items]
Sale of stock (in shares)					1,200,000
Sale of stock, option to purchase, term					30 days
August 2023 Sales Agreement
Class of Stock [Line Items]
Sale of stock (in shares)									914,828
Issuance price per share (USD per share) \| $ / shares									$ 58.31
Net proceeds from the business combination \| $							$ 0	$ 0	$ 52,500,000
Common Stock \| MoonLake AG
Class of Stock [Line Items]
Treasury stock, shares, acquired (in shares)	501
Common Class A
Class of Stock [Line Items]
Common shares, shares issued (in shares)							63,046,025						63,046,025	60,466,453
Common shares, shares outstanding (in shares)							63,046,025						63,046,025	60,466,453
Common shares, shares authorized (in shares)							500,000,000						500,000,000	500,000,000
Common shares, par value (USD per share) \| $ / shares							$ 0.0001						$ 0.0001	$ 0.0001
Common Class A \| Common Stock
Class of Stock [Line Items]
Common shares, shares issued (in shares)							63,046,025	62,874,637	62,874,637				63,046,025	60,466,453
Common shares, shares outstanding (in shares)				53,486,810			63,046,025	62,874,637	62,874,637	53,561,488	53,486,810	39,154,203	63,046,025	60,466,453			38,977,600
Common shares, shares authorized (in shares)							500,000,000	500,000,000	500,000,000				500,000,000	500,000,000
Common shares, par value (USD per share) \| $ / shares							$ 0.0001						$ 0.0001
Common shares, votes per share \| vote							1						1
Conversion and transfer of shares between classes (in shares)						153,998	153,998		1,493,356	74,678	4,587,713	176,603
Stock options exercised (in shares)							17,390
Common Class A \| Common Stock \| Conversion Of Class C into Class A
Class of Stock [Line Items]
Conversion and transfer of shares between classes (in shares)							153,998		1,493,356
Common Class C
Class of Stock [Line Items]
Common shares, shares issued (in shares)							841,269						841,269	2,505,476
Common shares, shares outstanding (in shares)							841,269						841,269	2,505,476
Common shares, shares authorized (in shares)							100,000,000						100,000,000	100,000,000
Common shares, par value (USD per share) \| $ / shares							$ 0.0001						$ 0.0001	$ 0.0001
Common Class C \| MoonLake AG
Class of Stock [Line Items]
Common shares, shares outstanding (in shares)																		3,700,257
Common Class C \| Common Stock
Class of Stock [Line Items]
Common shares, shares issued (in shares)							841,269	995,267	995,267				841,269	2,505,476
Common shares, shares outstanding (in shares)				8,959,195			841,269	995,267	995,267	8,884,517	8,959,195	13,546,908	841,269	2,505,476			13,723,511
Common shares, shares authorized (in shares)							100,000,000	100,000,000	100,000,000				100,000,000	100,000,000
Common shares, par value (USD per share) \| $ / shares							$ 0.0001						$ 0.0001
Common shares, votes per share \| vote							1						1
Conversion and transfer of shares between classes (in shares)						153,998	(153,998)		(1,493,356)	(74,678)	(4,587,713)	(176,603)
Common Class C \| Common Stock \| Conversion Of Class C into Class A
Class of Stock [Line Items]
Conversion and transfer of shares between classes (in shares)							(153,998)		(1,493,356)
Common Class C \| Common Stock \| MoonLake AG
Class of Stock [Line Items]
Treasury stock, shares, acquired (in shares)	16,853
MoonLake AG \| Common Stock
Class of Stock [Line Items]
Conversion and transfer of shares between classes (in shares)						4,578

Net Loss per Share - Calculatio

Net Loss per Share - Calculation of Net Loss per Share (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Numerator
Net loss attributable to controlling interests shareholders	$ (35,390,337)	$ (9,426,049)	$ (73,331,005)	$ (28,570,184)
Denominator
Total weighted average number of outstanding shares, basic (in shares)	62,896,782	53,517,655	62,803,220	45,485,650
Total weighted average number of outstanding shares, diluted (in shares)	62,896,782	53,517,655	62,803,220	45,485,650
Net loss per share - basic (in USD per share)	$ (0.56)	$ (0.18)	$ (1.17)	$ (0.63)
Net loss per share - diluted (in USD per share)	$ (0.56)	$ (0.18)	$ (1.17)	$ (0.63)

Net Loss per Share - Narrative

Net Loss per Share - Narrative (Details) - $ / shares		3 Months Ended		9 Months Ended
Net Loss per Share - Narrative (Details) - $ / shares	Nov. 01, 2024	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted-average number of shares, basic (in shares)		62,896,782	53,517,655	62,803,220	45,485,650
Weighted-average number of shares, diluted (in shares)		62,896,782	53,517,655	62,803,220	45,485,650
Net loss per share - basic (in USD per share)		$ (0.56)	$ (0.18)	$ (1.17)	$ (0.63)
Net loss per share - diluted (in USD per share)		$ (0.56)	$ (0.18)	$ (1.17)	$ (0.63)
Stock options exercised (in shares)		17,390
Pro forma
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted-average number of shares, basic (in shares)		63,881,246		63,809,450
Weighted-average number of shares, diluted (in shares)		63,881,246		63,809,450
Net loss per share - basic (in USD per share)		$ (0.57)		$ (1.17)
Net loss per share - diluted (in USD per share)		$ (0.57)		$ (1.17)
Common Class A
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted-average number of shares, basic (in shares)		62,896,782	53,517,655	62,803,220	45,485,650
Weighted-average number of shares, diluted (in shares)		62,896,782	53,517,655	62,803,220	45,485,650
Net loss per share - basic (in USD per share)		$ (0.56)	$ (0.18)	$ (1.17)	$ (0.63)
Net loss per share - diluted (in USD per share)		$ (0.56)	$ (0.18)	$ (1.17)	$ (0.63)
Number of shares outstanding (in shares)		63,046,025		63,046,025		60,466,453
Common Class A \| Pro forma \| Subsequent Event
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Number of shares outstanding (in shares)	63,905,198
Stock options exercised (in shares)	17,904

Share-Based Compensation - Narr

Share-Based Compensation - Narrative (Details)			3 Months Ended		9 Months Ended
Share-Based Compensation - Narrative (Details)	Apr. 05, 2022	Apr. 28, 2021 SFr / shares shares	Sep. 30, 2024 USD ($) plan co-founder shares	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($) plan co-founder shares	Sep. 30, 2023 USD ($)	Dec. 31, 2023 shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Number of share-based compensation plans \| plan			2		2
Share-based compensation expense \| $			$ 1,842,609	$ 1,425,651	$ 5,348,062	$ 5,500,499
Number of co-founders \| co-founder			3		3
Equity Incentive Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-based compensation expense \| $			$ 1,101,455	408,171	$ 3,156,505	721,155
Common shares issuable (in shares)			973,800		973,800
Weighted average period of recognition					1 year 11 months 15 days
Expiration period	10 years
Unrecognized compensation expense \| $			$ 11,200,000		$ 11,200,000
Employee Stock Option Plan (ESOP)
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Common shares issuable (in shares)			98,393		98,393
MoonLake AG Restricted Founder Shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-based compensation expense \| $			$ 0	0	$ 0	1,574,299
ESPP
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-based compensation expense \| $			741,154	762,309	2,191,557	2,590,576
Unrecognized share-based compensation expense, non-option awards \| $			3,800,000		$ 3,800,000
Weighted average period of recognition					1 year 3 months 18 days
ESPP \| Share-Based Payment Arrangement, Tranche One
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting percentage					25%
ESPP \| Share-Based Payment Arrangement, Tranche Two
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting percentage					25%
ESPP \| Share-Based Payment Arrangement, Tranche Three
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting percentage					25%
ESPP \| Share-Based Payment Arrangement, Tranche Four
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting percentage					25%
ESOP
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-based compensation expense \| $			$ 0	$ 255,171	$ 0	$ 614,469
ESOP \| Employee Stock Option Plan (ESOP) \| Share-Based Payment Arrangement, Tranche One
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting percentage					25%
ESOP \| Employee Stock Option Plan (ESOP) \| Share-Based Payment Arrangement, Tranche Two
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting percentage					25%
ESOP \| Employee Stock Option Plan (ESOP) \| Share-Based Payment Arrangement, Tranche Three
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting percentage					25%
ESOP \| Employee Stock Option Plan (ESOP) \| Share-Based Payment Arrangement, Tranche Four
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting percentage					25%
Common Class C
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Common shares, shares outstanding (in shares)			841,269		841,269		2,505,476
Common Class A
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, number of shares authorized (in shares)			4,353,948		4,353,948
Common shares issuable (in shares)			3,281,755		3,281,755
Common shares, shares outstanding (in shares)			63,046,025		63,046,025		60,466,453
MoonLake AG
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Reverse vesting percentage		90%
Common shares, shares outstanding (in shares)		110,000
MoonLake AG \| MoonLake AG Restricted Founder Shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Common shares, shares outstanding (in shares)		99,000
Vesting percentage		4.166%
Vesting period		2 years
Nominal value (CHF per share) \| SFr / shares		SFr 0.10
MoonLake AG \| Common Class C
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Common shares, shares outstanding (in shares)		3,700,257
MoonLake AG \| Common Class C \| MoonLake AG Restricted Founder Shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Common shares, shares outstanding (in shares)		3,330,231

Share-Based Compensation - Shar

Share-Based Compensation - Share-based Compensation Expense By Plan (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-based compensation expense	$ 1,842,609	$ 1,425,651	$ 5,348,062	$ 5,500,499
Research and Development Expense
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-based compensation expense	508,697	262,717	1,446,049	1,150,815
General and Administrative Expense
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-based compensation expense	1,333,912	1,162,934	3,902,013	4,349,684
Equity Incentive Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-based compensation expense	1,101,455	408,171	3,156,505	721,155
MoonLake AG Restricted Founder Shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-based compensation expense	0	0	0	1,574,299
ESPP
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-based compensation expense	741,154	762,309	2,191,557	2,590,576
ESOP
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-based compensation expense	$ 0	$ 255,171	$ 0	$ 614,469

Share-Based Compensation - Summ

Share-Based Compensation - Summary of Restricted Stock Awarded and Granted (Details) - MoonLake AG Restricted Founder Shares	9 Months Ended
	Sep. 30, 2023 shares
Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Awards unvested, beginning balance (in shares)	1,110,078
Awards vested (in shares)	(1,110,078)
Awards unvested, ending balance (in shares)	0

Share-Based Compensation - Su_2

Share-Based Compensation - Summary of ESPP Awarded and Granted (Details) - ESPP - shares	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Awards unvested, beginning balance (in shares)	2,237,915	2,237,915
Awards forfeited (in shares)	(16,853)
Awards unvested, ending balance (in shares)	2,221,062	2,237,915
Awards vested (in shares)	1,827,826	1,525,582

Share-Based Compensation - Su_3

Share-Based Compensation - Summary of ESOP Awarded and Granted (Details) - ESOP - Employee Stock Option Plan (ESOP) - shares	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding [Roll Forward]
Awards outstanding, beginning balance (in shares)	585,078	466,770
Additional awards granted (in shares)		133,444
Awards converted from ESOP to EIP (in shares)	(486,685)
Awards outstanding, ending balance (in shares)	98,393	600,214
Of which exercisable (in shares)	98,393	186,593

Share-Based Compensation - Su_4

Share-Based Compensation - Summary of Equity Incentive Plan Awarded and Granted (Details) - shares	3 Months Ended	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2024	Sep. 30, 2023
Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Awards exercised (in shares)	(17,390)
Equity Incentive Plan
Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Awards outstanding, beginning balance (in shares)		312,400	180,000
Additional awards granted (in shares)		241,820	56,485
Awards exercised (in shares)	(17,390)	(17,390)
Awards converted from ESOP to EIP (in shares)		486,685
Awards forfeited (in shares)		(49,715)
Awards outstanding, ending balance (in shares)	973,800	973,800	236,485
Of which exercisable (in shares)	368,910	368,910	60,000

Share-Based Compensation - Weig

Share-Based Compensation - Weighted Average Assumptions (Details) - Equity Incentive Plan	9 Months Ended
	Sep. 30, 2024 $ / shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Estimated fair value of the option on the grant date using Black-Scholes model (in dollars per share)	$ 31.31
Exercise price (in dollars per share)	$ 45.63
Expected term of the award	6 years
Expected volatility of the share price	75%
Risk-free interest rate	4.30%
Expected dividend rate	0%

Income Taxes (Details)

Income Taxes (Details)	3 Months Ended		9 Months Ended
Income Taxes (Details)	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Income Tax Disclosure [Abstract]
Effective income tax rate	0.30%	0.20%	0.30%	0.10%

Commitment and Contingencies (D

Commitment and Contingencies (Details) - Sep. 30, 2024 € in Millions, $ in Millions	USD ($)	EUR (€)
Other Commitments [Line Items]
Total commitments not yet recognized	$ 145.1
Prepaid Expenses, Current
Other Commitments [Line Items]
Total commitments not yet recognized	8
Prepaid Expenses, Noncurrent
Other Commitments [Line Items]
Total commitments not yet recognized	2.1
License \| SLK Program
Other Commitments [Line Items]
Revenue remaining performance obligation additional variable consideration amount	335.2	€ 299.6
Variable consideration amount	$ 8.1	€ 7.5

Segment Information and Geogr_3

Segment Information and Geographic Data - Schedule of Long-Lived Assets (Details) - USD ($)	Sep. 30, 2024	Dec. 31, 2023
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 3,832,575	$ 3,949,345
Switzerland
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	680,946	507,392
United Kingdom
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	2,012,806	2,704,555
Portugal
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 1,138,823	$ 737,398

Segment Information and Geogr_4

Segment Information and Geographic Data - Narrative (Details)	9 Months Ended
	Sep. 30, 2024 segment
Segment Reporting [Abstract]
Number of operating segments	1