Cerus (CERS) 10-Q5 May 222022 Q1 Quarterly reportFinancial data

Company Profile

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
Document and Entity Information - shares	Mar. 31, 2022	Apr. 22, 2022
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2022
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q1
Trading Symbol	CERS
Entity Registrant Name	CERUS CORPORATION
Entity Central Index Key	0001020214
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		176,898,227
Entity Current Reporting Status	Yes
Entity Shell Company	false
Title of 12(b) Security	Common Stock
Security Exchange Name	NASDAQ
Document Quarterly Report	true
Document Transition Report	false
Entity Interactive Data Current	Yes
Entity File Number	000-21937
Entity Tax Identification Number	68-0262011
Entity Incorporation, State or Country Code	DE
Entity Address, Address Line One	1220 Concord Avenue
Entity Address, Address Line Two	Suite 600
Entity Address, City or Town	Concord
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94520
City Area Code	925
Local Phone Number	288-6000

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 38,372	$ 48,759
Short-term investments	70,185	80,600
Accounts receivable	25,645	25,129
Current inventories	28,521	26,793
Prepaid and other current assets	10,089	5,821
Total current assets	172,812	187,102
Non-current assets:
Property and equipment, net	11,659	12,208
Operating lease right-of-use assets	13,665	12,971
Goodwill	1,316	1,316
Restricted cash	2,003	2,285
Other assets	20,451	21,617
Total assets	221,906	237,499
Current liabilities:
Accounts payable	31,474	35,608
Accrued liabilities	16,948	25,673
Debt – current	15,011	14,697
Operating lease liabilities – current	1,968	1,905
Deferred product revenue	1,258	673
Total current liabilities	66,659	78,556
Non-current liabilities:
Debt – non-current	54,769	54,724
Operating lease liabilities – non-current	16,787	16,260
Other non-current liabilities	3,280	2,342
Total liabilities	141,495	151,882
Commitments and contingencies
Stockholders' equity:
Common stock	177	174
Additional paid-in capital	1,057,497	1,048,936
Accumulated other comprehensive loss	(1,635)	(149)
Accumulated deficit	(976,626)	(964,342)
Total Cerus Corporation stockholders' equity	79,413	84,619
Noncontrolling interest	998	998
Total liabilities and stockholders' equity	$ 221,906	$ 237,499

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating expenses:
Research and development	$ 14,057	$ 15,748
Selling, general and administrative	20,735	19,170
Total operating expenses	34,792	34,918
Loss from operations	(9,848)	(16,447)
Non-operating expense, net:
Foreign exchange loss	(198)	(396)
Interest expense	(1,380)	(972)
Other (expense) income, net	(782)	456
Total non-operating expense, net	(2,360)	(912)
Loss before income taxes	(12,208)	(17,359)
Provision for income taxes	76	98
Net loss	(12,284)	(17,457)
Net loss attributable to Cerus Corporation	$ (12,284)	$ (17,457)
Net loss per share attributable to Cerus Corporation
Basic and diluted	$ (0.07)	$ (0.10)
Weighted average shares outstanding:
Basic and diluted	174,478	168,824
Product
Revenue	$ 37,444	$ 23,379
Cost of revenue	18,076	11,095
Gross profit	19,368	12,284
Government Contract
Revenue	$ 5,576	$ 6,187

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (12,284)	$ (17,457)
Other comprehensive (loss) income
Unrealized losses on available-for-sale investments, net of taxes	(1,486)	(218)
Comprehensive loss	(13,770)	(17,675)
Total comprehensive loss attributable to Cerus Corporation	$ (13,770)	$ (17,675)

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit	Noncontrolling Interests
Balance at Dec. 31, 2020	$ 103,806	$ 168	$ 1,012,932	$ 674	$ (909,968)
Balance (in shares) at Dec. 31, 2020		168,170
Issuance of common stock from exercise of stock options, vesting of restricted stock units, and ESPP purchases	1,171		1,171
Issuance of common stock from exercise of stock options, vesting of restricted stock units, and ESPP purchases (in shares)		2,621
Stock-based compensation	5,333		5,333
Other comprehensive loss	(218)			(218)
Net loss	(17,457)				(17,457)
Balance at Mar. 31, 2021	92,635	$ 168	1,019,436	456	(927,425)
Balance (in shares) at Mar. 31, 2021		170,791
Balance at Dec. 31, 2021	85,617	$ 174	1,048,936	(149)	(964,342)	$ 998
Balance (in shares) at Dec. 31, 2021		173,670
Issuance of common stock from exercise of stock options, vesting of restricted stock units, and ESPP purchases	2,138	$ 3	2,135
Issuance of common stock from exercise of stock options, vesting of restricted stock units, and ESPP purchases (in shares)		3,134
Stock-based compensation	6,426		6,426
Other comprehensive loss	(1,486)			(1,486)
Net loss	(12,284)				(12,284)
Balance at Mar. 31, 2022	$ 80,411	$ 177	$ 1,057,497	$ (1,635)	$ (976,626)	$ 998
Balance (in shares) at Mar. 31, 2022		176,804

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating activities
Net loss	$ (12,284)	$ (17,457)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	865	794
Stock-based compensation	6,426	5,333
Non-cash operating lease cost	396	321
Changes in valuation of warrant investment	281	(220)
Net loss on sale of available-for-sale securities	26
Unrealized gain on investments	(820)	(208)
Impairment of long-lived assets	542
Non-cash interest expense	464	104
Foreign currency remeasurement loss	287	206
Changes in operating assets and liabilities:
Accounts receivable	(564)	2,465
Inventories	(834)	(1,036)
Other assets	(4,111)	(2,693)
Accounts payable	(4,121)	(833)
Accrued liabilities and other non-current liabilities	(8,594)	(4,710)
Deferred product revenue	585	479
Net cash used in operating activities	(21,456)	(17,455)
Investing activities
Capital expenditures	(113)	(193)
Purchases of investments	(642)	(1,915)
Proceeds from maturities and sale of investments	9,377	23,500
Net cash provided by investing activities	8,622	21,392
Financing activities
Net proceeds from equity incentives	2,135	1,066
Net proceeds on revolving line of credit	314	1,422
Proceeds from loans		15,000
Net cash provided by financing activities	2,449	17,488
Effect of exchange rates on cash, cash equivalents, and restricted cash	(284)	(521)
Net (decrease) increase in cash, cash equivalents and restricted cash	(10,669)	20,904
Cash, cash equivalents and restricted cash, beginning of period	51,044	38,903
Cash, cash equivalents and restricted cash, end of period	$ 40,375	$ 59,807

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
Summary of Significant Accounting Policies	Mar. 31, 2022
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Note 1. Summary of Significant Accounting Policies Principles of Consolidation and Basis of Presentation The accompanying unaudited condensed consolidated financial statements include those of Cerus Corporation, its subsidiary, and its variable interest entity in which the Company is the primary beneficiary in accordance with the consolidation accounting guidance, after elimination of all intercompany accounts and transactions (together with Cerus Corporation, hereinafter “Cerus” or the “Company”). These condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America, or U.S. (“GAAP”) for interim financial information and pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of management, all adjustments, consisting of normal recurring entries, considered necessary for a fair presentation have been made. Operating results for the three months ended March 31, 2022, are not necessarily indicative of the results that may be expected for the year ending December 31, 2022, or for any future periods. These condensed consolidated financial statements and notes thereto should be read in conjunction with the Company’s audited consolidated financial statements and notes thereto for the year ended December 31, 2021, which were included in the Company’s 2021 Annual Report on Form 10-K, filed with the SEC on February 22, 2022. The accompanying condensed consolidated balance sheet as of December 31, 2021, has been derived from the Company’s audited consolidated financial statements as of that date . Immaterial Correction of an Error The Company determined the historical classification of the effects of foreign currency movements on the Company’s period-end foreign denominated cash balances was incorrectly presented as a component of the Company’s net cash used in operating activities as opposed to being presented separately as effect of exchange rates on cash. The Company determined that the impact of the error to previously issued financial statements was not material and has corrected the immaterial error in the comparative period within these financial statements. The impact of this correction for the three months ended March 31, 2021, was a reduction of net cash used in operating activities of $ 0.5 million with a corresponding amount presented separately as the effect of exchange rates on cash, cash equivalents, and restricted cash, for each of the period corrected. Use of Estimates The preparation of financial statements requires management to make estimates, assumptions and judgments that affect the reported amounts of assets, liabilities, revenue and expenses, and related disclosures of contingent assets and liabilities. On an ongoing basis, management evaluates its estimates, including those related to the nature and timing of satisfaction of performance obligations, the timing when the customer obtains control of products or services, the standalone selling price (“SSP”) of performance obligations, variable consideration, the collectability of accounts receivable, inventory reserves, fair values of investments, the allowance for credit losses, stock-based compensation, intangible assets and goodwill, useful lives of intangible assets and property and equipment, income taxes, accrued liabilities, and incremental borrowing rate, among others. The Company bases its estimates on historical experience, future projections, and on various other assumptions that are believed to be reasonable under the circumstances. Actual results may differ from those estimates under different assumptions or conditions. Revenue Revenue is recognized by applying the following five steps: (1) identify the contract(s) with a customer; (2) identify the performance obligations in the contract; (3) determine the transaction price; (4) allocate the transaction price to the performance obligations in the contract; and (5) recognize revenue when (or as) the entity satisfies a performance obligation. The Company’s main source of revenue is product revenue from sales of the INTERCEPT Blood System for platelets and plasma (“platelet and plasma systems” or “disposable kits”), UVA illumination devices (“illuminators”), INTERCEPT Fibrinogen Complex (“IFC”), spare parts and storage solutions, and maintenance services of illuminators. The Company sells its platelet and plasma systems directly to blood banks, hospitals, universities, government agencies, as well as to distributors in certain regions. The Company sells its IFC primarily to hospitals and blood banks. The Company uses a binding purchase order or signed sales contract as evidence of a contract and satisfaction of its policy. Generally, the Company’s sales contracts for disposable kits and illuminators with its customers do not provide for open return rights, except within a reasonable time after receipt of goods in the case of defective or non-conforming product. The contracts with customers can include various combinations of products and, to a lesser extent, services. The Company must determine whether products or services are capable of being distinct and accounted for as separate performance obligations, or are accounted for as a combined performance obligation. The Company must allocate the transaction price to each performance obligation on a relative SSP basis, and recognize the product revenue when the performance obligation is satisfied. The Company determines the SSP by using the historical selling price of the products and services. If the amount of consideration in a contract is variable, the Company estimates the amount of variable consideration that should be included in the transaction price using the most likely amount method, to the extent it is probable that a significant future reversal of cumulative product revenue under the contract will not occur. Product revenue is recognized upon transfer of control of promised products or services to customers in an amount that reflects the consideration to which the Company expects to receive in exchange for those products or services. Product revenue from the sale of illuminators, disposable kits, IFC, spare parts and storage solutions are recognized upon the transfer of control of the products to the customer. Product revenue from maintenance services are recognized ratably on a straight-line basis over the term of maintenance as customers simultaneously consume and receive benefits. Freight costs charged to customers are recorded as a component of product revenue. Taxes that the Company invoices to its customers and remits to governments are recorded on a net basis, which excludes such tax from product revenue. The Company receives reimbursement under its U.S. government contracts that support research and development of defined projects. The contracts generally provide for reimbursement of approved costs incurred under the terms of the contracts. Revenue related to the cost reimbursement provisions under the Company’s U.S. government contracts is recognized as the qualified direct and indirect costs on the projects are incurred. The Company invoices under its U.S. government contracts using the provisional rates in the government contracts and thus is subject to future audits at the discretion of the government. The Company believes that government contract revenue for periods not yet audited has been recorded in amounts that are expected to be realized upon final audit and settlement. However, these audits could result in an adjustment to government contract revenue previously reported, which adjustments could be potentially significant. Costs incurred related to services performed under the contracts are included as a component of research and development or selling, general and administrative expenses in the Company’s condensed consolidated statements of operations. The Company’s use of estimates in recording accrued liabilities for government contract activities (see “Use of Estimates” above) affects the revenue recorded from development funding and under the government contracts. Disaggregation of Product Revenue Product revenue by geographical locations of customers during the three months ended March 31, 2022 and 2021, were as follows (in thousands): Three Months Ended March 31, 2022 2021 Product revenue: North America $ 22,198 $ 9,664 Europe, Middle East and Africa 14,802 13,277 Other 444 438 Total product revenue $ 37,444 $ 23,379 Contract Balances The Company invoices its customers based upon the terms in the contracts, which generally requires payment 30 to 60 days from the date of invoice. Accounts receivable are recorded when the Company’s right to the consideration are estimated to be unconditional. The Company had no product revenue related contract assets at March 31, 2022 and December 31, 2021. Contract liabilities mainly consist of deferred product revenue related to maintenance services, unshipped products, and uninstalled illuminators. Maintenance services are generally billed upfront at the beginning of each annual service period and recognized ratably over the contractual service period. The Company applies an optional exemption to not disclose the value of unsatisfied performance obligations for contracts that have an original expected duration of one year or less. Research and Development Expenses Research and development (“R&D”) expenses are charged to expense when incurred, including cost incurred pursuant to the terms of the Company’s U.S. government contract. R&D expenses include salaries and related expenses for scientific and regulatory personnel, payments to consultants, supplies and chemicals used in in-house laboratories, costs of R&D facilities, depreciation of equipment and external contract research expenses, including clinical trials, preclinical safety studies, other laboratory studies, process development and product manufacturing for research use. The Company’s use of estimates in recording accrued liabilities for R&D activities (see “Use of Estimates” above) affects the amounts of R&D expenses recorded from development funding. Actual results may differ from those estimates under different assumptions or conditions. Cash Equivalents The Company considers all highly liquid investments with maturities of three months or less from the date of purchase to be classified as cash equivalents. These investments primarily consist of money market instruments and are classified as available-for-sale. Investments Investments with original maturities of greater than three months primarily include corporate debt and U.S. government agency securities that are designated as available-for-sale and classified as short-term investments. Available-for-sale securities are carried at estimated fair value. The Company views its available-for-sale portfolio as available for use in its current operations. Unrealized gains and losses derived by changes in the estimated fair value of available-for-sale securities were recorded in “Unrealized gains (losses) on available-for-sale investments, net of taxes” on the Company’s condensed consolidated statements of comprehensive loss. Realized gains (losses) from the sale of available-for-sale investments, if any, were determined on a specific identification method, and were recorded in “Other (expense) income, net” on the Company’s condensed consolidated statements of operations. The costs of securities sold are based on the specific identification method, if applicable. The Company reported the amortization of any premium and accretion of any discount resulting from the purchase of debt securities as a component of interest income. Deferred Compensation Plan The Company’s deferred compensation plan, pursuant to which compensation deferrals began in 2020, is a nonqualified deferred compensation plan that allows highly compensated employees to defer up to 80 percent of their base salary and up to 100 percent of their variable compensation each plan year. The Company may make discretionary contributions to each participant in an amount determined each year. To fund the deferred compensation plan's long-term liability, the Company purchases Company-owned life insurance contracts on certain employees. The insurance serves as an investment source for the funds being set aside. Participants in the deferred compensation plan select the mutual funds in which their compensation deferrals are deemed to be invested as a component of the insurance contracts. As of March 31, 2022 and December 31, 2021 , $ 1.9 million and $ 1.1 million, respectively, were included in "Other assets" on the Company's condensed consolidated balance sheets, which represents the cash surrender value of the associated life insurance policies, and $ 2.0 million and $ 1.2 million, respectively, were included in "Other non-current liabilities" on the Company's condensed consolidated balance sheets, which represents the carrying value of the liability for deferred compensation. Gains and losses on the investments related to the nonqualified deferred compensation plan are included in "Other income (expense), net", on the Company's condensed consolidated statements of operations, and corresponding changes in their deferred compensation liability are included in operating expenses. Restricted Cash As of March 31, 2022 and December 31, 2021, the Company’s “Restricted cash” consisted primarily of a letter of credit relating to an office building lease. As of March 31, 2022 and December 31, 2021 , the Company also had certain non-U.S. dollar denominated deposits recorded as “Restricted cash” in compliance with certain foreign contractual requirements. Concentration of Credit Risk Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash equivalents, available-for-sale securities and accounts receivable. Pursuant to the Company’s investment policy, substantially all of the Company’s cash, cash equivalents and available-for-sale securities are maintained at major financial institutions of high credit standing. The Company monitors the financial credit worthiness of the issuers of its investments and limits the concentration in individual securities and types of investments that exist within its investment portfolio. Generally, all of the Company’s investments carry high credit quality ratings, which is in accordance with its investment policy. At March 31, 2022, the Company does not believe there is significant financial risk from non-performance by the issuers of the Company’s cash equivalents and short-term investments. Concentrations of credit risk with respect to accounts receivable exist. On a regular basis, including at the time of sale, the Company performs credit evaluations of its significant customers that it expects to sell to on credit terms. Generally, the Company does not require collateral from its customers to secure accounts receivable. To the extent that the Company determines specific invoices or customer accounts may be uncollectible, the Company establishes an allowance for doubtful accounts against the accounts receivable on its condensed consolidated balance sheets and records a charge on its condensed consolidated statements of operations as a component of selling, general and administrative expenses. The Company had three customers and two customers that accounted for more than 10% of the Company’s outstanding accounts receivable at March 31, 2022 and December 31, 2021 , respectively. These customers cumulatively represented approximately 63 % and 48 % of the Company’s outstanding trade receivables at March 31, 2022 and December 31, 2021 , respectively. To date, the Company has not experienced collection difficulties from these customers. Inventories At March 31, 2022 and December 31, 2021 , inventory consisted of raw materials, work-in-process and finished goods. Finished goods include INTERCEPT disposable kits, illuminators, and certain replacement parts for the illuminators. Platelet and plasma systems’ disposable kits generally have 18 to 24 month shelf lives from the date of manufacture. Illuminators and replacement parts do not have regulated expiration dates. Raw materials and work-in-process includes certain components that are manufactured over a protracted length of time before being sold to, and ultimately incorporated and assembled by Fresenius Kabi Deutschland GmbH or Fresenius, Inc. (with their affiliates, “Fresenius”) into the finished INTERCEPT disposable kits. It is not customary for the Company’s production cycle for inventory to exceed 12 months, however, in certain circumstances the Company purchases inventory components it expects to consume beyond 12 months. The Company uses its best judgment to factor in lead times for the production of its raw materials, work-in-process and finished units to meet the Company’s forecasted demands. Additionally, from time-to-time, the Company may engage in strategic longer-range inventory purchases due to concentration of supplier risk, obsolescence of materials or components, or simply as safety stock to mitigate disruption to supply. Based upon estimated production needs and current inventory levels, the Company determines the amount of inventory necessary for the next 12 months. Any amounts in excess of this 12 month rolling projection are classified as Other assets in the consolidated balance sheets. Changes to those estimates could potentially impact amounts recorded as current or non-current. Inventory is recorded at the lower of cost, determined on a first-in, first-out basis, or net realizable value. The Company uses judgment to analyze and determine if the composition of its inventory is obsolete, slow-moving or unsalable and frequently reviews such determinations. The Company writes down specifically identified unusable, obsolete, slow-moving, or known unsalable inventory that has no alternative use in the period that it is first recognized by using a number of factors including product expiration dates, open and unfulfilled orders, and sales forecasts. Any write-down of its inventory to net realizable value establishes a new cost basis and will be maintained even if certain circumstances suggest that the inventory is recoverable in subsequent periods. Costs associated with the write-down of inventory are recorded within “Cost of product revenue” on the Company's condensed consolidated statements of operations. At March 31, 2022 and December 31, 2021 , the Company had $ 0.4 million and $ 0.2 million, respectively, recorded for potential obsolete, expiring or unsalable product. Property and Equipment, net Property and equipment is comprised of furniture, equipment, leasehold improvements, construction-in-progress, information technology hardware and software and is recorded at cost. At the time the property and equipment is ready for its intended use, it is depreciated on a straight-line basis over the estimated useful lives of the assets (generally three to five years ). Leasehold improvements are amortized on a straight-line basis over the shorter of the lease term or the estimated useful lives of the improvements. Goodwill Goodwill is not amortized, but instead is subject to an impairment test performed on an annual basis, or more frequently if events or changes in circumstances indicate that goodwill may be impaired. Such impairment analysis is performed on August 31 of each fiscal year, or more frequently if indicators of impairment exist. The test for goodwill impairment may be assessed using qualitative factors to determine whether it is more likely than not that the fair value of a reporting unit is less than the carrying amount. If the Company determines that it is more likely than not that the fair value of a reporting unit is less than the carrying amount, the Company must then proceed with performing the quantitative goodwill impairment test. The Company may choose not to perform the qualitative assessment to test goodwill for impairment and proceed directly to the quantitative impairment test; however, the Company may revert to the qualitative assessment to test goodwill for impairment in any subsequent period. The quantitative goodwill impairment test compares the fair value of each reporting unit with its respective carrying amount, including goodwill. The Company has determined that it operates in one reporting unit and estimates the fair value of its one reporting unit using the enterprise approach under which it considers the quoted market capitalization of the Company as reported on the Nasdaq Global Market. The Company considers quoted market prices that are available in active markets to be the best evidence of fair value. The Company also considers other factors, which include future forecasted results, the economic environment and overall market conditions. If the fair value of the reporting unit exceeds its carrying amount, goodwill of the reporting unit is considered not impaired. If the carrying amount of the reporting unit’s goodwill exceeds the implied fair value of that goodwill, an impairment loss is recognized in an amount equal to that excess, limited to the carrying amount of goodwill in the Company’s one reporting unit. Long-lived Assets The Company evaluates its long-lived assets for impairment by continually monitoring events and changes in circumstances that could indicate carrying amounts of its long-lived assets may not be recoverable. When such events or changes in circumstances occur, the Company assesses recoverability by determining whether the carrying value of such assets will be recovered through the undiscounted expected future cash flows. If the expected undiscounted future cash flows are less than the carrying amount of these assets, the Company then measures the amount of the impairment loss based on the excess of the carrying amount over the fair value of the assets. Foreign Currency Remeasurement The functional currency of the Company’s foreign subsidiary is the U.S. dollar. Monetary assets and liabilities denominated in foreign currencies are remeasured in U.S. dollars using the exchange rates at the balance sheet date. Non-monetary assets and liabilities denominated in foreign currencies are remeasured in U.S. dollars using historical exchange rates. Product revenues and expenses are remeasured using average exchange rates prevailing during the period. Remeasurements are recorded in “Foreign exchange loss” on the Company’s condensed consolidated statements of operations. Stock-Based Compensation Stock-based compensation expense is measured at the grant-date based on the fair value of the award and is recognized as expense on a straight-line basis over the requisite service period, which is the vesting period, and is adjusted for estimated forfeitures. To the extent that stock options contain performance criteria for vesting, stock-based compensation is recognized once the performance criteria are probable of being achieved. See Note 8 for further information regarding the Company’s stock-based compensation assumptions and expenses. Consolidated Variable Interest Entity In February 2021, the Company entered into an Equity Joint Venture Contract with Shandong Zhongbaokang Medical Implements Co., Ltd., or ZBK, to establish Cerus Zhongbaokang (Shandong) Biomedical Co., LTD., or the JV, for the purpose of developing, obtaining regulatory approval for, and eventual manufacturing and commercialization of the INTERCEPT blood transfusion for platelets and red blood cells in the People’s Republic of China. The Company owns 51 % of equity in the JV and consolidates the JV as it has determined that the investment is a variable interest entity, or VIE, and that the Company is the primary beneficiary. During September 2021, the Company contributed certain intangible intellectual property rights with zero recorded cost basis and recognized the $ 1.0 million equity funding contributed by ZBK as cash and as Noncontrolling interest in the Stockholders’ equity section of the consolidated balance sheet. Operating expenses for the JV were de minimis for the period presented. Income Taxes The provision for income taxes is accounted for using an asset and liability approach, under which deferred tax assets and liabilities are determined based on differences between the financial reporting and tax bases of assets and liabilities and are measured using the enacted tax rates and laws that will be in effect when the differences are expected to reverse. The Company does not recognize tax positions that do not have a greater than 50% likelihood of being recognized upon review by a taxing authority having full knowledge of all relevant information. Use of a valuation allowance is not an appropriate substitute for derecognition of a tax position. The Company recognizes accrued interest and penalties related to unrecognized tax benefits in its income tax expense. To date, the Company has not recognized any interest and penalties in its consolidated statements of operations, nor has it accrued for or made payments for interest and penalties. Although the Company believes it more likely than not that a taxing authority would agree with its current tax positions, there can be no assurance that the tax positions the Company has taken will be substantiated by a taxing authority if reviewed. The Company’s U.S. federal tax returns for years 2001 through 2020, California tax returns for years through 2020, and Netherlands tax returns for years 2017 through 2019 remain subject to examination by the taxing jurisdictions due to unutilized net operating losses and research credits. The Company continues to carry a valuation allowance on substantially all of its net deferred tax assets. Net Loss Per Share Attributable to Cerus Corporation Basic net loss per share attributable to Cerus Corporation is computed by dividing net loss attributable to Cerus Corporation by the weighted average number of common shares outstanding for the period. Diluted net loss per share attributable to Cerus Corporation gives effect to all potentially dilutive common shares outstanding for the period. The potentially dilutive securities include stock options, employee stock purchase plan rights and restricted stock units, which are calculated using the treasury stock method. For the three months ended March 31, 2022 and 2021, all potentially dilutive securities outstanding have been excluded from the computation of dilutive weighted average shares outstanding because such securities have an antidilutive impact due to losses reported. The table below presents potential shares that were excluded from the calculation of the weighted average number of shares outstanding used for the calculation of diluted net loss per share. These are excluded from the calculation due to their anti-dilutive effect for the three months ended March 31, 2022 and 2021 (shares in thousands): Three Months Ended March 31, 2022 2021 Weighted average number of anti-dilutive potential shares: Stock options 15,377 16,656 Restricted stock units 7,670 6,377 Employee stock purchase plan rights 40 44 Total 23,087 23,077 Leases The Company determines if an arrangement is a lease at inception. Operating leases are included in operating lease right-of-use (“ROU”) assets and operating lease liabilities in the Company’s condensed consolidated balance sheets. As of March 31, 2022 and December 31, 2021, the Company did not have finance leases. ROU assets and operating lease liabilities are recognized at commencement date based on the present value of lease payments over the lease term. The Company uses its incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments. The ROU asset also includes any lease payments made and excludes lease incentives. The lease terms may include options to extend or terminate the lease when it is reasonably certain to be exercised. Operating leases are recognized on a straight-line basis over the lease term. Guarantee and Indemnification Arrangements The Company recognizes the fair value for guarantee and indemnification arrangements issued or modified by the Company. In addition, the Company monitors the conditions that are subject to the guarantees and indemnifications in order to identify if a loss has occurred. If the Company determines it is probable that a loss has occurred, then any such estimable loss would be recognized under those guarantees and indemnifications. Some of the agreements that the Company is a party to contain provisions that indemnify the counter party from damages and costs resulting from claims that the Company’s technology infringes the intellectual property rights of a third-party or claims that the sale or use of the Company’s products have caused personal injury or other damage or loss. The Company has not received any such requests for indemnification under these provisions and has not been required to make material payments pursuant to these provisions. The Company generally provides for a one-year warranty on certain of its disposable kits and illuminators covering defects in materials and workmanship. The Company accrues costs associated with warranty obligations when claims become known and are estimable. The Company has no t experienced significant or systemic warranty claims nor is it aware of any existing current warranty claims. Accordingly, the Company had not accrued for any future warranty costs for its products at March 31, 2022 and December 31, 2021 . Fair Value of Financial Instruments The Company applies the provisions of fair value relating to its financial assets and liabilities. The carrying amounts of accounts receivables, accounts payable, and other accrued liabilities approximate their fair value due to the relative short-term maturities. Based on the borrowing rates currently available to the Company for loans with similar terms, the Company believes the fair value of its debt approximates their carrying amounts. The Company measures and records certain financial assets and liabilities at fair value on a recurring basis, including its available-for-sale securities. The Company classifies instruments within Level 1 if quoted prices are available in active markets for identical assets, which include the Company’s cash accounts and money market funds. The Company classifies instruments in Level 2 if the instruments are valued using observable inputs to quoted market prices, benchmark yields, reported trades, broker/dealer quotes or alternative pricing sources with reasonable levels of price transparency. These instruments include the Company’s corporate debt and U.S. government agency securities holdings. The available-for-sale securities are held by a custodian who obtains investment prices from a third-party pricing provider that uses standard inputs (observable in the market) to models which vary by asset class. The Company classifies instruments in Level 3 if one or more significant inputs or significant value drivers are unobservable. The Company assesses any transfers among fair value measurement levels at the end of each reporting period. See Note 2 for further information regarding the Company’s valuation of financial instruments.

Available-for-sale Securities a

Available-for-sale Securities and Fair Value on Financial Instruments	3 Months Ended
	Mar. 31, 2022
Fair Value Disclosures [Abstract]
Available-for-sale Securities and Fair Value on Financial Instruments	Note 2. Available-for-sale Securities and Fair Value on Financial Instruments Available-for-sale Securities The following is a summary of available-for-sale securities at March 31, 2022 (in thousands): March 31, 2022 Amortized Cost Gross Gross Allowance for Credit Loss Fair Value Money market funds $ 11,187 $ — $ — $ — $ 11,187 United States government agency securities 20,757 — ( 506 ) — 20,251 Corporate debt securities 48,574 8 ( 1,039 ) — 47,543 Mortgage-backed securities 2,489 2 ( 100 ) — 2,391 Total available-for-sale securities $ 83,007 $ 10 $ ( 1,645 ) $ — $ 81,372 The following is a summary of available-for-sale securities at December 31, 2021 (in thousands): December 31, 2021 Amortized Cost Gross Gross Allowance for Credit Loss Fair Value Money market funds $ 7,170 $ — $ — $ — $ 7,170 United States government agency securities 25,761 1 ( 77 ) — 25,685 Corporate debt securities 52,611 105 ( 156 ) — 52,560 Mortgage-backed securities 2,377 — ( 22 ) — 2,355 Total available-for-sale securities $ 87,919 $ 106 $ ( 255 ) $ — $ 87,770 Available-for-sale securities at March 31, 2022 and December 31, 2021, consisted of the following by contractual maturity (in thousands): March 31, 2022 December 31, 2021 Amortized Cost Fair Value Amortized Cost Fair Value One year or less $ 40,197 $ 40,113 $ 44,873 $ 44,952 Greater than one year and less than five years 42,810 41,259 43,046 42,818 Total available-for-sale securities $ 83,007 $ 81,372 $ 87,919 $ 87,770 The following tables shows all available-for-sale marketable securities in an unrealized loss position for which an allowance for credit losses has not been recognized and the related gross unrealized losses and fair value, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position (in thousands): March 31, 2022 Less than 12 Months 12 Months or Greater Total Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss Corporate debt securities $ 41,507 $ ( 1,039 ) $ — $ — $ 41,507 $ ( 1,039 ) United States government agency securities 20,251 ( 506 ) — — 20,251 ( 506 ) Mortgage-backed securities 2,139 ( 100 ) — — 2,139 ( 100 ) Total $ 63,897 $ ( 1,645 ) $ — $ — $ 63,897 $ ( 1,645 ) December 31, 2021 Less than 12 Months 12 Months or Greater Total Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss Corporate debt securities $ 27,909 $ ( 153 ) $ 998 $ ( 3 ) $ 28,907 $ ( 156 ) United States government agency securities 18,367 ( 75 ) 1,019 ( 2 ) 19,386 ( 77 ) Mortgage-backed securities 2,355 ( 22 ) 0 0 2,355 ( 22 ) Total $ 48,631 $ ( 250 ) $ 2,017 $ ( 5 ) $ 50,648 $ ( 255 ) , the Company did no t recognize any expected credit losses. The Company has no current requirement or intent to sell the securities in an unrealized loss position. The Company expects to recover up to (or beyond) the initial cost of investment for securities held. The Company recorded no gross realized gains or losses from the sale or maturity of available-for-sale investments during the three months ended March 31, 2022 and 2021, respectively. Fair Value Disclosures The Company uses certain assumptions that market participants would use to determine the fair value of an asset or liability in pricing the asset or liability in an orderly transaction between market participants at the measurement date. The identification of market participant assumptions provides a basis for determining what inputs are to be used for pricing each asset or liability. A fair value hierarchy has been established which gives precedence to fair value measurements calculated using observable inputs over those using unobservable inputs. This hierarchy prioritized the inputs into three broad levels as follows: • Level 1: Quoted prices in active markets for identical instruments • Level 2: Other significant observable inputs (including quoted prices in active markets for similar instruments) • Level 3: Significant unobservable inputs (including assumptions in determining the fair value of certain investments) Money market funds are highly liquid investments and are actively traded. The pricing information on these investment instruments are readily available and can be independently validated as of the measurement date. This approach results in the classification of these securities as Level 1 of the fair value hierarchy. To estimate the fair value of Level 2 debt securities as of March 31, 2022, the Company’s primary pricing service relies on inputs from multiple industry-recognized pricing sources to determine the price for each investment. Corporate debt and U.S. government agency securities are systematically priced by this service as of the close of business each business day. If the primary pricing service does not price a specific asset a secondary pricing service is utilized. To estimate the fair value of the Company’s Level 3 warrant investments as of March 31, 2022, the Company uses a standard Black-Scholes option pricing model, using a class volatility consistent with the seniority and preference rights of the underlying preferred stock. Key assumptions used in the valuation include the privately held company’s preferred stock price, warrant exercise price, equity volatility, expected term of warrant, risk-free interest rates, and details specific to the warrant. The Company recognizes the changes in the fair value of this warrant in “Other income, net” on the Company’s condensed consolidated statements of operations. The fair values of the Company’s financial assets and liabilities were determined using the following inputs at March 31, 2022 (in thousands): Balance sheet Quoted Significant Significant Unobservable Inputs classification Total (Level 1) (Level 2) (Level 3) Money market funds Cash and cash equivalents $ 11,187 $ 11,187 $ — $ — United States government agency securities Short-term investments 20,251 — 20,251 — Corporate debt securities Short-term investments 47,543 — 47,543 — Mortgage-backed securities Short-term investments 2,391 — 2,391 — Total short-term investments 81,372 11,187 70,185 — Warrants Other assets 290 — — 290 Total financial assets $ 81,662 $ 11,187 $ 70,185 $ 290 The fair values of the Company’s financial assets and liabilities were determined using the following inputs at December 31, 2021 (in thousands): Balance sheet Quoted Significant Significant Unobservable Inputs classification Total (Level 1) (Level 2) (Level 3) Money market funds Cash and cash equivalents $ 7,170 $ 7,170 $ — $ — United States government agency securities Short-term investments 25,685 — 25,685 — Corporate debt securities Short-term investments 52,560 — 52,560 — Mortgage-backed securities Short-term investments 2,355 — 2,355 — Total short-term investments 87,770 7,170 80,600 — Warrants Other assets 570 — — 570 Total financial assets $ 88,340 $ 7,170 $ 80,600 $ 570 The Company did not have any transfers among fair value measurement levels during the three months ended March 31, 2022 and 2021. The following table provides a summary of the total gain recognized in the Company’s condensed consolidated statements of operations due to changes in the fair value of the warrant (in thousands): Three Months Ended 2022 2021 (Loss) gain from changes in the fair value of level 3 investments $ ( 280 ) $ 220

Inventories, net

Inventories, net	3 Months Ended
Inventories, net	Mar. 31, 2022
Inventory Disclosure [Abstract]
Inventories, net	Note 3. Inventories, net Inventories, net at March 31, 2022 and December 31, 2021, consisted of the following (in thousands): March 31, 2022 December 31, 2021 Raw materials $ 13,939 $ 15,664 Work-in-process 5,289 5,044 Finished goods 24,418 22,129 Total inventories 43,646 42,837 Less: non-current inventories 15,125 16,044 Total current inventories $ 28,521 $ 26,793 Non-current inventories, which primarily consists of work-in-process, is included in Other assets in the condensed consolidated balance sheets.

Accrued Liabilities

Accrued Liabilities	3 Months Ended
Accrued Liabilities	Mar. 31, 2022
Payables And Accruals [Abstract]
Accrued Liabilities	Note 4. Accrued Liabilities Accrued liabilities at March 31, 2022 and December 31, 2021, consisted of the following (in thousands): March 31, 2022 December 31, 2021 Accrued compensation and related costs $ 10,673 $ 18,506 Accrued professional services 3,004 3,942 Other accrued expenses 3,271 3,225 Total accrued liabilities $ 16,948 $ 25,673

Debt

Debt	3 Months Ended
Debt	Mar. 31, 2022
Debt Disclosure [Abstract]
Debt	Note 5. Debt Debt at March 31, 2022, consisted of the following (in thousands): Principal Unamortized Discount Total Term Loan Credit Agreement $ 55,000 $ ( 231 ) $ 54,769 Less: current portion of term loan — — — Non-current portion of term loan $ 55,000 $ ( 231 ) $ 54,769 Debt at December 31, 2021, consisted of the following (in thousands): Principal Unamortized Discount Net Carrying Term Loan Credit Agreement $ 55,000 $ ( 276 ) $ 54,724 Less: current portion of term loan — — — Non-current portion of term loan $ 55,000 $ ( 276 ) $ 54,724 Principal, interest and fee payments on Term Loan Credit Agreement at March 31, 2022, are expected to be as follows (in thousands): Year ended December 31, Principal Interest and Fees Total 2022 $ — $ 3,151 $ 3,151 2023 41,250 3,134 44,384 2024 13,750 1,826 15,576 Total $ 55,000 $ 8,111 $ 63,111 Loan Agreements On March 29, 2019, the Company entered into a Credit, Security and Guaranty Agreement (Term Loan) (the “Term Loan Credit Agreement”) with MidCap Financial Trust (“MidCap”) to borrow up to $ 70 million in three tranches (collectively “2019 Term Loan”), with a maturity date of March 1, 2024 . The first advance of $ 40.0 million (“Tranche 1”) was drawn by the Company on March 29, 2019, with the proceeds used in part to repay in full the outstanding term loans and fees under a prior loan agreement. The second advance of $ 15.0 million (“Tranche 2”) was drawn by the Company on March 29, 2021. The third advance of $ 15.0 million (“Tranche 3”) expired on December 31, 2021 . The borrowings under the 2019 Term Loan bear interest at the sum of a fixed percentage spread and the greater of (i) 1.8 % or (ii) one month LIBOR. At March 31, 2022 , the effective interest rate on the Term Loan was approximately 7.50 %. This debt requires interest-only payments through March 1, 2023 , followed by 12 month s of payments with interest and equal payment of principal. Prepayments of the 2019 Term Loan under the Term Loan Credit Agreement, in whole or in part, will be subject to early termination fees which decline each year until the fourth anniversary of the applicable funding date, at which time there is no early termination fee. Upon the final payment, the Company must also pay an exit fee calculated based on a percentage of the aggregate principal amount of all tranches advanced to the Company. The Company uses the effective interest method to recognize the final payment over the term of the debt. The Company also maintains a Credit, Security and Guaranty Agreement (Revolving Loan) (the “Revolving Loan Credit Agreement”) with MidCap. The borrowing limit under the Revolving Loan Credit Agreement is $ 15.0 million. The amount borrowed under the Revolving Loan Credit Agreement can be increased, upon request by the Company, by up to an additional $ 5.0 million, subject to agent and lender approval and the satisfaction of certain conditions. The Revolving Loan Credit Agreement has a maturity date of March 1, 2024 . Amounts drawn under the Revolving Loan Credit Agreement bear interest at the sum of a fixed percentage spread and the greater of (i) 1.80 % or (ii) one-month LIBOR. There are also fractional fees based on the amounts either drawn or undrawn. If the Revolving Loan Credit Agreement is terminated before maturity or the funding obligation is permanently reduced, there are termination fees which decline each anniversary until the third anniversary, at which time there is no termination fee. As of March 31, 2022 and December 31, 2021 , the Company had borrowed $ 15.0 million and $ 14.7 million under the Revolving Loan Credit Agreement, respectively, which is included in “Debt – current” in the Company's condensed consolidated balance sheets. The Term Loan Credit Agreement and Revolving Loan Credit Agreement contain certain financial and non-financial covenants, with which the Company was in compliance at March 31, 2022 . Additionally, both agreements are secured by substantially all of the Company’s assets, with some exclusions.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
Commitments and Contingencies	Mar. 31, 2022
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 6. Commitments and Contingencies Operating Leases The Company leases its office facilities, located in Concord, California and Amersfoort, the Netherlands, and certain equipment and automobiles under non-cancelable operating leases with initial terms in excess of one year that require the Company to pay operating costs, property taxes, insurance and maintenance. The operating leases expire at various dates through 2030 , with certain of the leases providing for renewal options, provisions for adjusting future lease payments based on the consumer price index, and the right to terminate the lease early. The Company does not assume renewals in determination of the lease term unless the renewals are deemed to be reasonably assured at lease commencement. The Company recorded the lease right-of-use asset and obligation at the present value of lease payments over the lease term. The rates implicit in the Company’s leases are generally not readily determinable. The Company must estimate its incremental borrowing rate to discount the lease payments to present value. Operating lease assets also include lease incentives. Supplemental cash flow information related to operating leases is as follows (dollars in thousands): Three Months Ended March 31, 2022 2021 Cash payments for operating leases $ 910 $ 1,000 Right-of-use assets obtained in exchange for operating lease obligations 1,315 41 2022 2021 Weighted-average remaining lease term 7.1 years 8.3 years Weighted-average discount rate 8.3 % 9.0 % Future minimum non-cancelable payments under operating leases as of March 31, 2022, were as follows (in thousands): Operating Leases 2022 (remainder) $ 2,535 2023 3,519 2024 3,418 2025 3,115 2026 3,071 Thereafter 10,779 Total future lease payments 26,437 Less imputed interest 7,682 Present value of lease liabilities $ 18,755 The operating lease expense for the three months ended March 31, 2022 and 2021, were as follows: Three Months Ended March 31, 2022 2021 Operating lease expense $ 848 $ 802 As of March 31, 2022 , the Company had no leases that have not yet commenced. Purchase Commitments The Company is party to agreements with certain providers for certain components of the INTERCEPT Blood System. Certain of these agreements require minimum purchase commitments from the Company. As of March 31, 2022 , the Company had $ 23.4 million of short-term purchase commitments and $ 2.7 million of long-term purchase commitments, which are not recorded in the Company’s condensed consolidated balance sheets.

Stockholders' Equity

Stockholders' Equity	3 Months Ended
Stockholders' Equity	Mar. 31, 2022
Equity [Abstract]
Stockholders' Equity	Note 7. Stockholders’ Equity Sales Agreement On December 11, 2020, the Company entered into the Controlled Equity Offering SM Sales Agreement (the “Sales Agreement”) with Cantor Fitzgerald & Co. and Stifel, Nicolaus & Company, Incorporated (each a “Sales Agent” and collectively, the “Sales Agents”), under which the Company may issue and sell from time to time up to $ 100.0 million of the Company’s common stock through or to the Sales Agents, as sales agent or principal. Under the Sales Agreement, each Sales Agent receives compensation based on an aggregate of 2 % of the gross proceeds on the sale price per share of the Company’s common stock. The issuance and sale of these shares by the Company pursuant to the Sales Agreement are deemed an “at-the-market” offering and are registered under the Securities Act of 1933, as amended. During the three months ended March 31, 2022 , no shares of the Company’s common stock were sold under the Sales Agreement. At March 31, 2022 , the Company had approximately $ 96.8 million of common stock available to be sold under the Sales Agreement.

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended
Stock-Based Compensation	Mar. 31, 2022
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation	Note 8. Stock-Based Compensation Employee Stock Plans Employee Stock Purchase Plan The Company maintains an Employee Stock Purchase Plan (the “Purchase Plan”), which is intended to qualify as an employee stock purchase plan within the meaning of Section 423(b) of the Internal Revenue Code. Under the Purchase Plan, the Company’s Board of Directors may authorize participation by eligible employees, including officers, in periodic offerings. Under the Purchase Plan eligible employee participants may purchase shares of common stock of the Company at a purchase price equal to 85 % of the lower of the fair market value per share on the start date of the offering period or the fair market value per share on the purchase date. The Purchase Plan consists of a fixed offering period of 12 months with two purchase periods within each offering period. In June 2020, the Company’s stockholders approved an amendment and restatement of the Purchase Plan that increased the aggregate number of shares of common stock authorized for issuance under the Purchase Plan by 1.5 million shares. At March 31, 2022 , the Company had 1.5 million shares available for future issuance. 2008 Equity Incentive Plan and Inducement Plan The Company also maintains an equity compensation plan to provide long-term incentives for employees, contractors, and members of its Board of Directors. The Company currently grants equity awards from one plan, the 2008 Equity Incentive Plan and its subsequent amendments (collectively, the “Amended 2008 Plan”). The Amended 2008 Plan allows for the issuance of non-statutory and incentive stock options, restricted stock, restricted stock units (“RSUs”), stock appreciation rights, other stock-related awards, and performance awards which may be settled in cash, stock, or other property. In June 2019, the Company’s stockholders approved an amendment and restatement of the Amended 2008 Plan that increased the aggregate number of shares of common stock authorized for issuance by 11.8 million shares. In June 2020, the Company’s stockholders approved an amendment and restatement of the Amended 2008 Plan that increased the aggregate number of shares of common stock authorized for issuance by 5.0 million shares. In June 2021, the Company’s stockholders approved an amendment and restatement of the Amended 2008 Plan that increased the aggregate number of shares of common stock authorized for issuance by 7.6 million shares. Option awards under the Amended 2008 Plan generally have a maximum term of ten years from the date of the award. The Amended 2008 Plan generally requires options to be granted at 100 % of the fair market value of the Company’s common stock subject to the option on the date of grant. Options granted by the Company to employees generally vest over four years . RSUs are measured based on the fair market value of the underlying stock on the date of grant. RSUs granted by the Company to employees generally vest over three to four years . Performance-based stock granted under the Amended 2008 Plan are limited to 500,000 shares of common stock per calendar year. Performance-based cash awards granted under the Amended 2008 Plan are limited to $ 1.0 million per recipient per calendar year. At March 31, 2022 , 1.4 million shares of performance-based stock awards were outstanding. At March 31, 2022 , the Company had approximately 27.5 million shares of its common stock subject to outstanding options or unvested RSUs, or remaining available for future issuance under the Amended 2008 Plan, of which approximately 16.0 million shares and 8.1 million shares were subject to outstanding options and unvested RSUs, respectively, and approximately 3.4 million shares were available for future issuance under the Amended 2008 Plan. The Company’s policy is to issue new shares of common stock upon the exercise of options or vesting of RSUs. Activity under the Company’s equity incentive plans related to stock options is set forth below (in thousands except per share amounts): Number of Weighted Average Balance at December 31, 2021 15,092 $ 5.02 Granted 1,385 5.76 Exercised ( 424 ) 3.79 Forfeited/canceled ( 31 ) 6.15 Balance at March 31, 2022 16,022 5.11 Activity under the Company’s equity incentive plans related to RSUs is set forth below (in thousands except per share amounts): Number of Weighted Average Balance at December 31, 2021 6,689 $ 5.90 Granted (1) 4,097 5.77 Vested (1) ( 2,597 ) 5.66 Forfeited (1) ( 67 ) 5.94 Balance at March 31, 2022 8,122 5.91 (1) Includes shares issuable under performance-based restricted stock unit awards. Valuation Assumptions for Stock-based Compensation The Company uses the Black-Scholes option pricing model to determine the grant-date fair value of stock options and employee stock purchase plan rights. The Black-Scholes option pricing model is affected by the Company’s stock price, as well as assumptions regarding a number of complex and subjective variables, which include the expected term of the grants, actual and projected employee stock option exercise behaviors, including forfeitures, the Company’s expected stock price volatility, the risk-free interest rate and expected dividends. The Company recognizes the grant-date fair value of the stock award as stock-based compensation expense on a straight-line basis over the requisite service period, which is the vesting period, and is adjusted for estimated forfeitures.

Income Taxes

Income Taxes	3 Months Ended
Income Taxes	Mar. 31, 2022
Income Tax Disclosure [Abstract]
Income Taxes	Note 9. Income Taxes The Company recorded income tax expense of $ 0.1 million and $ 0.1 million, respectively, for the three months ended March 31, 2022 and 2021 , primarily related to the operating profit of the Company’s Cerus Europe B.V. subsidiary.

Development and License Agreeme

Development and License Agreements	3 Months Ended
Development and License Agreements	Mar. 31, 2022
Development And License Agreements [Abstract]
Development and License Agreements	Note 10. Development and License Agreements Agreements with Fresenius Fresenius Kabi AG (“Fresenius”) manufactures and supplies the platelet and plasma systems to the Company under a supply agreement (the “Supply Agreement”). Fresenius is obligated to sell, and the Company is obligated to purchase, finished disposable kits for the Company’s platelet and plasma systems and the Company’s red blood cell system product candidate (the “RBC Sets”). The Supply Agreement permits the Company to purchase platelet and plasma systems and RBC Sets from third parties to the extent necessary to maintain supply qualifications with such third parties or where local or regional manufacturing is needed to obtain product registrations or sales. Pricing terms per unit were initially fixed and declined at specified annual production levels, and are subject to certain adjustments after the initial pricing term. Under the Supply Agreement, the Company maintains the amounts due from the components sold to Fresenius as a current asset on its accompanying condensed consolidated balance sheets until such time as Fresenius makes payment to the Company. The initial term of the Supply Agreement extends through July 1, 2025 (the “Initial Term”) and is automatically renewed thereafter for additional two-year terms (each, a “Renewal Term”), subject to termination by either party upon (i) two years written notice prior to the expiration of the Initial Term or (ii) one year written notice prior to the expiration of any Renewal Term. Under the Supply Agreement, the Company has the right, but not the obligation, to purchase certain assets and assume certain liabilities from Fresenius. Government contracts In June 2016, the Company entered into an agreement with Biomedical Advanced Research and Development Authority (“BARDA”) to support the Company’s development and implementation of pathogen reduction technology for platelet, plasma, and red blood cells. The agreement with BARDA and its subsequent modifications include a base period (the “Base Period”) and option periods (each, an “Option Period”). The agreement includes committed funding for clinical development of the INTERCEPT Blood System for red blood cells (the “red blood cell system”). In June 2021, BARDA committed an additional $ 9.6 million raising the committed funding to up to $ 126.5 million as of March 31, 2022 , and the potential for the exercise by BARDA of subsequent Option Periods that, if exercised by BARDA and completed, would bring the total funding opportunity to $ 223.5 million through December 31, 2023. If exercised by BARDA, subsequent Option Periods would fund activities related to broader implementation of the platelet and plasma system or the red blood cell system in areas of emerging pathogens, clinical and regulatory development programs in support of the potential licensure of the red blood cell system in the U.S., and development, manufacturing and scale-up activities for the red blood cell system. The Company could be responsible for up to $ 9.6 million of co-investment if certain Option Periods are exercised. BARDA will make periodic assessments of the Company’s progress and the continuation of the agreement is based on the Company’s success in completing the required tasks under the Base Period and each exercised Option Period. BARDA has rights under certain contract clauses to terminate the agreement, including the ability to terminate the agreement for convenience at any time. As of March 31, 2022 and December 31, 2021 , $ 4.6 million and $ 4.7 million, respectively, of unbilled amounts were included in accounts receivable on the Company’s condensed consolidated balance sheets related to BARDA. In September 2020, the Company entered into a five-year agreement with the U.S. Food and Drug Administration for the development of next-generation compounds to optimize pathogen reduction treatment of whole blood to reduce the risk of transfusion-transmitted infections. The total potential contract value is $ 11.1 million. As of March 31, 2022 and December 31, 2021 , $ 0.3 million and $ 0.2 million, respectively, of billed and unbilled amounts were included in accounts receivable on the Company’s condensed consolidated balance sheets related to FDA.

Segment, Customer and Geographi

Segment, Customer and Geographic Information	3 Months Ended
Segment, Customer and Geographic Information	Mar. 31, 2022
Segment Reporting [Abstract]
Segment, Customer and Geographic Information	Note 11. Segment, Customer and Geographic Information The Company continues to operate in only one segment, blood safety. The Company’s chief executive officer is the chief operating decision maker who evaluates performance based on the net revenues and operating loss of the blood safety segment. The Company considers the sale of all of its INTERCEPT Blood System products to be similar in nature and function, and any revenue earned from services is minimal. The Company’s operations outside of the U.S. include a wholly-owned subsidiary headquartered in Europe. The Company’s operations in the U.S. are responsible for the R&D and global and domestic commercialization of the INTERCEPT Blood System, while operations in Europe are responsible for the commercialization efforts of the platelet and plasma systems in Europe, the Commonwealth of Independent States and the Middle East. Product revenues are attributed to each region based on the location of the customer, and in the case of non-product revenues, on the location of the collaboration partner. The Company had the following significant customers that accounted for more than 10% of the Company’s total product revenue, during the three months ended March 31, 2022 and 2021(in percentage): Three Months Ended March 31 2022 2021 American Red Cross 35 % 22 % Établissement Français du Sang 13 % 22 %

Subsequent Event

Subsequent Event	3 Months Ended
Subsequent Event	Mar. 31, 2022
Subsequent Events [Abstract]
Subsequent Event	Note 12. Subsequent Event In May 2022, the Company signed a ten-year contract extension with Fresenius to manufacture and supply sets for the INTERCEPT Blood System. Fresenius will continue manufacturing finished disposable kits for the INTERCEPT Blood System and scale production capabilities at additional sites. The Company is currently assessing the impact of the new agreement on the Company's consolidated financial statements.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
Summary of Significant Accounting Policies (Policies)	Mar. 31, 2022
Accounting Policies [Abstract]
Principles of Consolidation and Basis of Presentation	Principles of Consolidation and Basis of Presentation The accompanying unaudited condensed consolidated financial statements include those of Cerus Corporation, its subsidiary, and its variable interest entity in which the Company is the primary beneficiary in accordance with the consolidation accounting guidance, after elimination of all intercompany accounts and transactions (together with Cerus Corporation, hereinafter “Cerus” or the “Company”). These condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America, or U.S. (“GAAP”) for interim financial information and pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of management, all adjustments, consisting of normal recurring entries, considered necessary for a fair presentation have been made. Operating results for the three months ended March 31, 2022, are not necessarily indicative of the results that may be expected for the year ending December 31, 2022, or for any future periods. These condensed consolidated financial statements and notes thereto should be read in conjunction with the Company’s audited consolidated financial statements and notes thereto for the year ended December 31, 2021, which were included in the Company’s 2021 Annual Report on Form 10-K, filed with the SEC on February 22, 2022. The accompanying condensed consolidated balance sheet as of December 31, 2021, has been derived from the Company’s audited consolidated financial statements as of that date .
Immaterial Correction of an Error	Immaterial Correction of an Error The Company determined the historical classification of the effects of foreign currency movements on the Company’s period-end foreign denominated cash balances was incorrectly presented as a component of the Company’s net cash used in operating activities as opposed to being presented separately as effect of exchange rates on cash. The Company determined that the impact of the error to previously issued financial statements was not material and has corrected the immaterial error in the comparative period within these financial statements. The impact of this correction for the three months ended March 31, 2021, was a reduction of net cash used in operating activities of $ 0.5 million with a corresponding amount presented separately as the effect of exchange rates on cash, cash equivalents, and restricted cash, for each of the period corrected.
Use of Estimates	Use of Estimates The preparation of financial statements requires management to make estimates, assumptions and judgments that affect the reported amounts of assets, liabilities, revenue and expenses, and related disclosures of contingent assets and liabilities. On an ongoing basis, management evaluates its estimates, including those related to the nature and timing of satisfaction of performance obligations, the timing when the customer obtains control of products or services, the standalone selling price (“SSP”) of performance obligations, variable consideration, the collectability of accounts receivable, inventory reserves, fair values of investments, the allowance for credit losses, stock-based compensation, intangible assets and goodwill, useful lives of intangible assets and property and equipment, income taxes, accrued liabilities, and incremental borrowing rate, among others. The Company bases its estimates on historical experience, future projections, and on various other assumptions that are believed to be reasonable under the circumstances. Actual results may differ from those estimates under different assumptions or conditions.
Revenue	Revenue Revenue is recognized by applying the following five steps: (1) identify the contract(s) with a customer; (2) identify the performance obligations in the contract; (3) determine the transaction price; (4) allocate the transaction price to the performance obligations in the contract; and (5) recognize revenue when (or as) the entity satisfies a performance obligation. The Company’s main source of revenue is product revenue from sales of the INTERCEPT Blood System for platelets and plasma (“platelet and plasma systems” or “disposable kits”), UVA illumination devices (“illuminators”), INTERCEPT Fibrinogen Complex (“IFC”), spare parts and storage solutions, and maintenance services of illuminators. The Company sells its platelet and plasma systems directly to blood banks, hospitals, universities, government agencies, as well as to distributors in certain regions. The Company sells its IFC primarily to hospitals and blood banks. The Company uses a binding purchase order or signed sales contract as evidence of a contract and satisfaction of its policy. Generally, the Company’s sales contracts for disposable kits and illuminators with its customers do not provide for open return rights, except within a reasonable time after receipt of goods in the case of defective or non-conforming product. The contracts with customers can include various combinations of products and, to a lesser extent, services. The Company must determine whether products or services are capable of being distinct and accounted for as separate performance obligations, or are accounted for as a combined performance obligation. The Company must allocate the transaction price to each performance obligation on a relative SSP basis, and recognize the product revenue when the performance obligation is satisfied. The Company determines the SSP by using the historical selling price of the products and services. If the amount of consideration in a contract is variable, the Company estimates the amount of variable consideration that should be included in the transaction price using the most likely amount method, to the extent it is probable that a significant future reversal of cumulative product revenue under the contract will not occur. Product revenue is recognized upon transfer of control of promised products or services to customers in an amount that reflects the consideration to which the Company expects to receive in exchange for those products or services. Product revenue from the sale of illuminators, disposable kits, IFC, spare parts and storage solutions are recognized upon the transfer of control of the products to the customer. Product revenue from maintenance services are recognized ratably on a straight-line basis over the term of maintenance as customers simultaneously consume and receive benefits. Freight costs charged to customers are recorded as a component of product revenue. Taxes that the Company invoices to its customers and remits to governments are recorded on a net basis, which excludes such tax from product revenue. The Company receives reimbursement under its U.S. government contracts that support research and development of defined projects. The contracts generally provide for reimbursement of approved costs incurred under the terms of the contracts. Revenue related to the cost reimbursement provisions under the Company’s U.S. government contracts is recognized as the qualified direct and indirect costs on the projects are incurred. The Company invoices under its U.S. government contracts using the provisional rates in the government contracts and thus is subject to future audits at the discretion of the government. The Company believes that government contract revenue for periods not yet audited has been recorded in amounts that are expected to be realized upon final audit and settlement. However, these audits could result in an adjustment to government contract revenue previously reported, which adjustments could be potentially significant. Costs incurred related to services performed under the contracts are included as a component of research and development or selling, general and administrative expenses in the Company’s condensed consolidated statements of operations. The Company’s use of estimates in recording accrued liabilities for government contract activities (see “Use of Estimates” above) affects the revenue recorded from development funding and under the government contracts. Disaggregation of Product Revenue Product revenue by geographical locations of customers during the three months ended March 31, 2022 and 2021, were as follows (in thousands): Three Months Ended March 31, 2022 2021 Product revenue: North America $ 22,198 $ 9,664 Europe, Middle East and Africa 14,802 13,277 Other 444 438 Total product revenue $ 37,444 $ 23,379 Contract Balances The Company invoices its customers based upon the terms in the contracts, which generally requires payment 30 to 60 days from the date of invoice. Accounts receivable are recorded when the Company’s right to the consideration are estimated to be unconditional. The Company had no product revenue related contract assets at March 31, 2022 and December 31, 2021. Contract liabilities mainly consist of deferred product revenue related to maintenance services, unshipped products, and uninstalled illuminators. Maintenance services are generally billed upfront at the beginning of each annual service period and recognized ratably over the contractual service period. The Company applies an optional exemption to not disclose the value of unsatisfied performance obligations for contracts that have an original expected duration of one year or less.
Research and Development Expenses	Research and Development Expenses Research and development (“R&D”) expenses are charged to expense when incurred, including cost incurred pursuant to the terms of the Company’s U.S. government contract. R&D expenses include salaries and related expenses for scientific and regulatory personnel, payments to consultants, supplies and chemicals used in in-house laboratories, costs of R&D facilities, depreciation of equipment and external contract research expenses, including clinical trials, preclinical safety studies, other laboratory studies, process development and product manufacturing for research use. The Company’s use of estimates in recording accrued liabilities for R&D activities (see “Use of Estimates” above) affects the amounts of R&D expenses recorded from development funding. Actual results may differ from those estimates under different assumptions or conditions.
Cash Equivalents	Cash Equivalents The Company considers all highly liquid investments with maturities of three months or less from the date of purchase to be classified as cash equivalents. These investments primarily consist of money market instruments and are classified as available-for-sale.
Investments	Investments Investments with original maturities of greater than three months primarily include corporate debt and U.S. government agency securities that are designated as available-for-sale and classified as short-term investments. Available-for-sale securities are carried at estimated fair value. The Company views its available-for-sale portfolio as available for use in its current operations. Unrealized gains and losses derived by changes in the estimated fair value of available-for-sale securities were recorded in “Unrealized gains (losses) on available-for-sale investments, net of taxes” on the Company’s condensed consolidated statements of comprehensive loss. Realized gains (losses) from the sale of available-for-sale investments, if any, were determined on a specific identification method, and were recorded in “Other (expense) income, net” on the Company’s condensed consolidated statements of operations. The costs of securities sold are based on the specific identification method, if applicable. The Company reported the amortization of any premium and accretion of any discount resulting from the purchase of debt securities as a component of interest income.
Deferred Compensation Plan	Deferred Compensation Plan The Company’s deferred compensation plan, pursuant to which compensation deferrals began in 2020, is a nonqualified deferred compensation plan that allows highly compensated employees to defer up to 80 percent of their base salary and up to 100 percent of their variable compensation each plan year. The Company may make discretionary contributions to each participant in an amount determined each year. To fund the deferred compensation plan's long-term liability, the Company purchases Company-owned life insurance contracts on certain employees. The insurance serves as an investment source for the funds being set aside. Participants in the deferred compensation plan select the mutual funds in which their compensation deferrals are deemed to be invested as a component of the insurance contracts. As of March 31, 2022 and December 31, 2021 , $ 1.9 million and $ 1.1 million, respectively, were included in "Other assets" on the Company's condensed consolidated balance sheets, which represents the cash surrender value of the associated life insurance policies, and $ 2.0 million and $ 1.2 million, respectively, were included in "Other non-current liabilities" on the Company's condensed consolidated balance sheets, which represents the carrying value of the liability for deferred compensation. Gains and losses on the investments related to the nonqualified deferred compensation plan are included in "Other income (expense), net", on the Company's condensed consolidated statements of operations, and corresponding changes in their deferred compensation liability are included in operating expenses.
Restricted Cash	Restricted Cash As of March 31, 2022 and December 31, 2021, the Company’s “Restricted cash” consisted primarily of a letter of credit relating to an office building lease. As of March 31, 2022 and December 31, 2021 , the Company also had certain non-U.S. dollar denominated deposits recorded as “Restricted cash” in compliance with certain foreign contractual requirements.
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash equivalents, available-for-sale securities and accounts receivable. Pursuant to the Company’s investment policy, substantially all of the Company’s cash, cash equivalents and available-for-sale securities are maintained at major financial institutions of high credit standing. The Company monitors the financial credit worthiness of the issuers of its investments and limits the concentration in individual securities and types of investments that exist within its investment portfolio. Generally, all of the Company’s investments carry high credit quality ratings, which is in accordance with its investment policy. At March 31, 2022, the Company does not believe there is significant financial risk from non-performance by the issuers of the Company’s cash equivalents and short-term investments. Concentrations of credit risk with respect to accounts receivable exist. On a regular basis, including at the time of sale, the Company performs credit evaluations of its significant customers that it expects to sell to on credit terms. Generally, the Company does not require collateral from its customers to secure accounts receivable. To the extent that the Company determines specific invoices or customer accounts may be uncollectible, the Company establishes an allowance for doubtful accounts against the accounts receivable on its condensed consolidated balance sheets and records a charge on its condensed consolidated statements of operations as a component of selling, general and administrative expenses. The Company had three customers and two customers that accounted for more than 10% of the Company’s outstanding accounts receivable at March 31, 2022 and December 31, 2021 , respectively. These customers cumulatively represented approximately 63 % and 48 % of the Company’s outstanding trade receivables at March 31, 2022 and December 31, 2021 , respectively. To date, the Company has not experienced collection difficulties from these customers.
Inventories	Inventories At March 31, 2022 and December 31, 2021 , inventory consisted of raw materials, work-in-process and finished goods. Finished goods include INTERCEPT disposable kits, illuminators, and certain replacement parts for the illuminators. Platelet and plasma systems’ disposable kits generally have 18 to 24 month shelf lives from the date of manufacture. Illuminators and replacement parts do not have regulated expiration dates. Raw materials and work-in-process includes certain components that are manufactured over a protracted length of time before being sold to, and ultimately incorporated and assembled by Fresenius Kabi Deutschland GmbH or Fresenius, Inc. (with their affiliates, “Fresenius”) into the finished INTERCEPT disposable kits. It is not customary for the Company’s production cycle for inventory to exceed 12 months, however, in certain circumstances the Company purchases inventory components it expects to consume beyond 12 months. The Company uses its best judgment to factor in lead times for the production of its raw materials, work-in-process and finished units to meet the Company’s forecasted demands. Additionally, from time-to-time, the Company may engage in strategic longer-range inventory purchases due to concentration of supplier risk, obsolescence of materials or components, or simply as safety stock to mitigate disruption to supply. Based upon estimated production needs and current inventory levels, the Company determines the amount of inventory necessary for the next 12 months. Any amounts in excess of this 12 month rolling projection are classified as Other assets in the consolidated balance sheets. Changes to those estimates could potentially impact amounts recorded as current or non-current. Inventory is recorded at the lower of cost, determined on a first-in, first-out basis, or net realizable value. The Company uses judgment to analyze and determine if the composition of its inventory is obsolete, slow-moving or unsalable and frequently reviews such determinations. The Company writes down specifically identified unusable, obsolete, slow-moving, or known unsalable inventory that has no alternative use in the period that it is first recognized by using a number of factors including product expiration dates, open and unfulfilled orders, and sales forecasts. Any write-down of its inventory to net realizable value establishes a new cost basis and will be maintained even if certain circumstances suggest that the inventory is recoverable in subsequent periods. Costs associated with the write-down of inventory are recorded within “Cost of product revenue” on the Company's condensed consolidated statements of operations. At March 31, 2022 and December 31, 2021 , the Company had $ 0.4 million and $ 0.2 million, respectively, recorded for potential obsolete, expiring or unsalable product.
Property and Equipment, net	Property and Equipment, net Property and equipment is comprised of furniture, equipment, leasehold improvements, construction-in-progress, information technology hardware and software and is recorded at cost. At the time the property and equipment is ready for its intended use, it is depreciated on a straight-line basis over the estimated useful lives of the assets (generally three to five years ). Leasehold improvements are amortized on a straight-line basis over the shorter of the lease term or the estimated useful lives of the improvements.
Goodwill	Goodwill Goodwill is not amortized, but instead is subject to an impairment test performed on an annual basis, or more frequently if events or changes in circumstances indicate that goodwill may be impaired. Such impairment analysis is performed on August 31 of each fiscal year, or more frequently if indicators of impairment exist. The test for goodwill impairment may be assessed using qualitative factors to determine whether it is more likely than not that the fair value of a reporting unit is less than the carrying amount. If the Company determines that it is more likely than not that the fair value of a reporting unit is less than the carrying amount, the Company must then proceed with performing the quantitative goodwill impairment test. The Company may choose not to perform the qualitative assessment to test goodwill for impairment and proceed directly to the quantitative impairment test; however, the Company may revert to the qualitative assessment to test goodwill for impairment in any subsequent period. The quantitative goodwill impairment test compares the fair value of each reporting unit with its respective carrying amount, including goodwill. The Company has determined that it operates in one reporting unit and estimates the fair value of its one reporting unit using the enterprise approach under which it considers the quoted market capitalization of the Company as reported on the Nasdaq Global Market. The Company considers quoted market prices that are available in active markets to be the best evidence of fair value. The Company also considers other factors, which include future forecasted results, the economic environment and overall market conditions. If the fair value of the reporting unit exceeds its carrying amount, goodwill of the reporting unit is considered not impaired. If the carrying amount of the reporting unit’s goodwill exceeds the implied fair value of that goodwill, an impairment loss is recognized in an amount equal to that excess, limited to the carrying amount of goodwill in the Company’s one reporting unit.
Long-lived Assets	Long-lived Assets The Company evaluates its long-lived assets for impairment by continually monitoring events and changes in circumstances that could indicate carrying amounts of its long-lived assets may not be recoverable. When such events or changes in circumstances occur, the Company assesses recoverability by determining whether the carrying value of such assets will be recovered through the undiscounted expected future cash flows. If the expected undiscounted future cash flows are less than the carrying amount of these assets, the Company then measures the amount of the impairment loss based on the excess of the carrying amount over the fair value of the assets.
Foreign Currency Remeasurement	Foreign Currency Remeasurement The functional currency of the Company’s foreign subsidiary is the U.S. dollar. Monetary assets and liabilities denominated in foreign currencies are remeasured in U.S. dollars using the exchange rates at the balance sheet date. Non-monetary assets and liabilities denominated in foreign currencies are remeasured in U.S. dollars using historical exchange rates. Product revenues and expenses are remeasured using average exchange rates prevailing during the period. Remeasurements are recorded in “Foreign exchange loss” on the Company’s condensed consolidated statements of operations.
Stock-Based Compensation	Stock-Based Compensation Stock-based compensation expense is measured at the grant-date based on the fair value of the award and is recognized as expense on a straight-line basis over the requisite service period, which is the vesting period, and is adjusted for estimated forfeitures. To the extent that stock options contain performance criteria for vesting, stock-based compensation is recognized once the performance criteria are probable of being achieved. See Note 8 for further information regarding the Company’s stock-based compensation assumptions and expenses.
Consolidated Variable Interest Entities	Consolidated Variable Interest Entity In February 2021, the Company entered into an Equity Joint Venture Contract with Shandong Zhongbaokang Medical Implements Co., Ltd., or ZBK, to establish Cerus Zhongbaokang (Shandong) Biomedical Co., LTD., or the JV, for the purpose of developing, obtaining regulatory approval for, and eventual manufacturing and commercialization of the INTERCEPT blood transfusion for platelets and red blood cells in the People’s Republic of China. The Company owns 51 % of equity in the JV and consolidates the JV as it has determined that the investment is a variable interest entity, or VIE, and that the Company is the primary beneficiary. During September 2021, the Company contributed certain intangible intellectual property rights with zero recorded cost basis and recognized the $ 1.0 million equity funding contributed by ZBK as cash and as Noncontrolling interest in the Stockholders’ equity section of the consolidated balance sheet. Operating expenses for the JV were de minimis for the period presented.
Income Taxes	Income Taxes The provision for income taxes is accounted for using an asset and liability approach, under which deferred tax assets and liabilities are determined based on differences between the financial reporting and tax bases of assets and liabilities and are measured using the enacted tax rates and laws that will be in effect when the differences are expected to reverse. The Company does not recognize tax positions that do not have a greater than 50% likelihood of being recognized upon review by a taxing authority having full knowledge of all relevant information. Use of a valuation allowance is not an appropriate substitute for derecognition of a tax position. The Company recognizes accrued interest and penalties related to unrecognized tax benefits in its income tax expense. To date, the Company has not recognized any interest and penalties in its consolidated statements of operations, nor has it accrued for or made payments for interest and penalties. Although the Company believes it more likely than not that a taxing authority would agree with its current tax positions, there can be no assurance that the tax positions the Company has taken will be substantiated by a taxing authority if reviewed. The Company’s U.S. federal tax returns for years 2001 through 2020, California tax returns for years through 2020, and Netherlands tax returns for years 2017 through 2019 remain subject to examination by the taxing jurisdictions due to unutilized net operating losses and research credits. The Company continues to carry a valuation allowance on substantially all of its net deferred tax assets.
Net Loss Per Share Attributable to Cerus Corporation	Net Loss Per Share Attributable to Cerus Corporation Basic net loss per share attributable to Cerus Corporation is computed by dividing net loss attributable to Cerus Corporation by the weighted average number of common shares outstanding for the period. Diluted net loss per share attributable to Cerus Corporation gives effect to all potentially dilutive common shares outstanding for the period. The potentially dilutive securities include stock options, employee stock purchase plan rights and restricted stock units, which are calculated using the treasury stock method. For the three months ended March 31, 2022 and 2021, all potentially dilutive securities outstanding have been excluded from the computation of dilutive weighted average shares outstanding because such securities have an antidilutive impact due to losses reported. The table below presents potential shares that were excluded from the calculation of the weighted average number of shares outstanding used for the calculation of diluted net loss per share. These are excluded from the calculation due to their anti-dilutive effect for the three months ended March 31, 2022 and 2021 (shares in thousands): Three Months Ended March 31, 2022 2021 Weighted average number of anti-dilutive potential shares: Stock options 15,377 16,656 Restricted stock units 7,670 6,377 Employee stock purchase plan rights 40 44 Total 23,087 23,077
Leases	Leases The Company determines if an arrangement is a lease at inception. Operating leases are included in operating lease right-of-use (“ROU”) assets and operating lease liabilities in the Company’s condensed consolidated balance sheets. As of March 31, 2022 and December 31, 2021, the Company did not have finance leases. ROU assets and operating lease liabilities are recognized at commencement date based on the present value of lease payments over the lease term. The Company uses its incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments. The ROU asset also includes any lease payments made and excludes lease incentives. The lease terms may include options to extend or terminate the lease when it is reasonably certain to be exercised. Operating leases are recognized on a straight-line basis over the lease term.
Guarantee and Indemnification Arrangements	Guarantee and Indemnification Arrangements The Company recognizes the fair value for guarantee and indemnification arrangements issued or modified by the Company. In addition, the Company monitors the conditions that are subject to the guarantees and indemnifications in order to identify if a loss has occurred. If the Company determines it is probable that a loss has occurred, then any such estimable loss would be recognized under those guarantees and indemnifications. Some of the agreements that the Company is a party to contain provisions that indemnify the counter party from damages and costs resulting from claims that the Company’s technology infringes the intellectual property rights of a third-party or claims that the sale or use of the Company’s products have caused personal injury or other damage or loss. The Company has not received any such requests for indemnification under these provisions and has not been required to make material payments pursuant to these provisions. The Company generally provides for a one-year warranty on certain of its disposable kits and illuminators covering defects in materials and workmanship. The Company accrues costs associated with warranty obligations when claims become known and are estimable. The Company has no t experienced significant or systemic warranty claims nor is it aware of any existing current warranty claims. Accordingly, the Company had not accrued for any future warranty costs for its products at March 31, 2022 and December 31, 2021 .
Fair Value of Financial Instruments	Fair Value of Financial Instruments The Company applies the provisions of fair value relating to its financial assets and liabilities. The carrying amounts of accounts receivables, accounts payable, and other accrued liabilities approximate their fair value due to the relative short-term maturities. Based on the borrowing rates currently available to the Company for loans with similar terms, the Company believes the fair value of its debt approximates their carrying amounts. The Company measures and records certain financial assets and liabilities at fair value on a recurring basis, including its available-for-sale securities. The Company classifies instruments within Level 1 if quoted prices are available in active markets for identical assets, which include the Company’s cash accounts and money market funds. The Company classifies instruments in Level 2 if the instruments are valued using observable inputs to quoted market prices, benchmark yields, reported trades, broker/dealer quotes or alternative pricing sources with reasonable levels of price transparency. These instruments include the Company’s corporate debt and U.S. government agency securities holdings. The available-for-sale securities are held by a custodian who obtains investment prices from a third-party pricing provider that uses standard inputs (observable in the market) to models which vary by asset class. The Company classifies instruments in Level 3 if one or more significant inputs or significant value drivers are unobservable. The Company assesses any transfers among fair value measurement levels at the end of each reporting period. See Note 2 for further information regarding the Company’s valuation of financial instruments.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	3 Months Ended
Summary of Significant Accounting Policies (Tables)	Mar. 31, 2022
Accounting Policies [Abstract]
Summary of Product Revenue by Geographical Locations of Customers	Product revenue by geographical locations of customers during the three months ended March 31, 2022 and 2021, were as follows (in thousands): Three Months Ended March 31, 2022 2021 Product revenue: North America $ 22,198 $ 9,664 Europe, Middle East and Africa 14,802 13,277 Other 444 438 Total product revenue $ 37,444 $ 23,379
Anti-Dilutive Effect of Common Shares	The table below presents potential shares that were excluded from the calculation of the weighted average number of shares outstanding used for the calculation of diluted net loss per share. These are excluded from the calculation due to their anti-dilutive effect for the three months ended March 31, 2022 and 2021 (shares in thousands): Three Months Ended March 31, 2022 2021 Weighted average number of anti-dilutive potential shares: Stock options 15,377 16,656 Restricted stock units 7,670 6,377 Employee stock purchase plan rights 40 44 Total 23,087 23,077

Available-for-sale Securities_2

Available-for-sale Securities and Fair Value on Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2022
Fair Value Disclosures [Abstract]
Summary of Available-for-Sale Securities	The following is a summary of available-for-sale securities at March 31, 2022 (in thousands): March 31, 2022 Amortized Cost Gross Gross Allowance for Credit Loss Fair Value Money market funds $ 11,187 $ — $ — $ — $ 11,187 United States government agency securities 20,757 — ( 506 ) — 20,251 Corporate debt securities 48,574 8 ( 1,039 ) — 47,543 Mortgage-backed securities 2,489 2 ( 100 ) — 2,391 Total available-for-sale securities $ 83,007 $ 10 $ ( 1,645 ) $ — $ 81,372 The following is a summary of available-for-sale securities at December 31, 2021 (in thousands): December 31, 2021 Amortized Cost Gross Gross Allowance for Credit Loss Fair Value Money market funds $ 7,170 $ — $ — $ — $ 7,170 United States government agency securities 25,761 1 ( 77 ) — 25,685 Corporate debt securities 52,611 105 ( 156 ) — 52,560 Mortgage-backed securities 2,377 — ( 22 ) — 2,355 Total available-for-sale securities $ 87,919 $ 106 $ ( 255 ) $ — $ 87,770
Available-for-Sale Debt Securities by Original Contractual Maturity	Available-for-sale securities at March 31, 2022 and December 31, 2021, consisted of the following by contractual maturity (in thousands): March 31, 2022 December 31, 2021 Amortized Cost Fair Value Amortized Cost Fair Value One year or less $ 40,197 $ 40,113 $ 44,873 $ 44,952 Greater than one year and less than five years 42,810 41,259 43,046 42,818 Total available-for-sale securities $ 83,007 $ 81,372 $ 87,919 $ 87,770
Available-for-Sale Marketable Securities in Unrealized Position	The following tables shows all available-for-sale marketable securities in an unrealized loss position for which an allowance for credit losses has not been recognized and the related gross unrealized losses and fair value, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position (in thousands): March 31, 2022 Less than 12 Months 12 Months or Greater Total Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss Corporate debt securities $ 41,507 $ ( 1,039 ) $ — $ — $ 41,507 $ ( 1,039 ) United States government agency securities 20,251 ( 506 ) — — 20,251 ( 506 ) Mortgage-backed securities 2,139 ( 100 ) — — 2,139 ( 100 ) Total $ 63,897 $ ( 1,645 ) $ — $ — $ 63,897 $ ( 1,645 ) December 31, 2021 Less than 12 Months 12 Months or Greater Total Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss Corporate debt securities $ 27,909 $ ( 153 ) $ 998 $ ( 3 ) $ 28,907 $ ( 156 ) United States government agency securities 18,367 ( 75 ) 1,019 ( 2 ) 19,386 ( 77 ) Mortgage-backed securities 2,355 ( 22 ) 0 0 2,355 ( 22 ) Total $ 48,631 $ ( 250 ) $ 2,017 $ ( 5 ) $ 50,648 $ ( 255 )
Fair Values of Financial Assets and Liabilities	The fair values of the Company’s financial assets and liabilities were determined using the following inputs at March 31, 2022 (in thousands): Balance sheet Quoted Significant Significant Unobservable Inputs classification Total (Level 1) (Level 2) (Level 3) Money market funds Cash and cash equivalents $ 11,187 $ 11,187 $ — $ — United States government agency securities Short-term investments 20,251 — 20,251 — Corporate debt securities Short-term investments 47,543 — 47,543 — Mortgage-backed securities Short-term investments 2,391 — 2,391 — Total short-term investments 81,372 11,187 70,185 — Warrants Other assets 290 — — 290 Total financial assets $ 81,662 $ 11,187 $ 70,185 $ 290 The fair values of the Company’s financial assets and liabilities were determined using the following inputs at December 31, 2021 (in thousands): Balance sheet Quoted Significant Significant Unobservable Inputs classification Total (Level 1) (Level 2) (Level 3) Money market funds Cash and cash equivalents $ 7,170 $ 7,170 $ — $ — United States government agency securities Short-term investments 25,685 — 25,685 — Corporate debt securities Short-term investments 52,560 — 52,560 — Mortgage-backed securities Short-term investments 2,355 — 2,355 — Total short-term investments 87,770 7,170 80,600 — Warrants Other assets 570 — — 570 Total financial assets $ 88,340 $ 7,170 $ 80,600 $ 570
Summary of Gain Recognized in Condensed Consolidated Statements of Operations Due to Changes in Fair Value of Warrant	The following table provides a summary of the total gain recognized in the Company’s condensed consolidated statements of operations due to changes in the fair value of the warrant (in thousands): Three Months Ended 2022 2021 (Loss) gain from changes in the fair value of level 3 investments $ ( 280 ) $ 220

Inventories, net (Tables)

Inventories, net (Tables)	3 Months Ended
Inventories, net (Tables)	Mar. 31, 2022
Inventory Disclosure [Abstract]
Inventories, net	Inventories, net at March 31, 2022 and December 31, 2021, consisted of the following (in thousands): March 31, 2022 December 31, 2021 Raw materials $ 13,939 $ 15,664 Work-in-process 5,289 5,044 Finished goods 24,418 22,129 Total inventories 43,646 42,837 Less: non-current inventories 15,125 16,044 Total current inventories $ 28,521 $ 26,793

Accrued Liabilities (Tables)

Accrued Liabilities (Tables)	3 Months Ended
Accrued Liabilities (Tables)	Mar. 31, 2022
Payables And Accruals [Abstract]
Accrued Liabilities	Accrued liabilities at March 31, 2022 and December 31, 2021, consisted of the following (in thousands): March 31, 2022 December 31, 2021 Accrued compensation and related costs $ 10,673 $ 18,506 Accrued professional services 3,004 3,942 Other accrued expenses 3,271 3,225 Total accrued liabilities $ 16,948 $ 25,673

Debt (Tables)

Debt (Tables)	3 Months Ended
Debt (Tables)	Mar. 31, 2022
Debt Disclosure [Abstract]
Debt	Debt at March 31, 2022, consisted of the following (in thousands): Principal Unamortized Discount Total Term Loan Credit Agreement $ 55,000 $ ( 231 ) $ 54,769 Less: current portion of term loan — — — Non-current portion of term loan $ 55,000 $ ( 231 ) $ 54,769 Debt at December 31, 2021, consisted of the following (in thousands): Principal Unamortized Discount Net Carrying Term Loan Credit Agreement $ 55,000 $ ( 276 ) $ 54,724 Less: current portion of term loan — — — Non-current portion of term loan $ 55,000 $ ( 276 ) $ 54,724
Expected Principal, Interest and Fee Payments on Term Loan Credit Agreement	Principal, interest and fee payments on Term Loan Credit Agreement at March 31, 2022, are expected to be as follows (in thousands): Year ended December 31, Principal Interest and Fees Total 2022 $ — $ 3,151 $ 3,151 2023 41,250 3,134 44,384 2024 13,750 1,826 15,576 Total $ 55,000 $ 8,111 $ 63,111

Commitments and Contingencies (

Commitments and Contingencies (Tables)	3 Months Ended
Commitments and Contingencies (Tables)	Mar. 31, 2022
Commitments And Contingencies Disclosure [Abstract]
Supplemental Cash Flow Information Related to Operating Leases	Supplemental cash flow information related to operating leases is as follows (dollars in thousands): Three Months Ended March 31, 2022 2021 Cash payments for operating leases $ 910 $ 1,000 Right-of-use assets obtained in exchange for operating lease obligations 1,315 41 2022 2021 Weighted-average remaining lease term 7.1 years 8.3 years Weighted-average discount rate 8.3 % 9.0 %
Future Minimum Non-Cancelable Lease Payments Under Operating Leases	Future minimum non-cancelable payments under operating leases as of March 31, 2022, were as follows (in thousands): Operating Leases 2022 (remainder) $ 2,535 2023 3,519 2024 3,418 2025 3,115 2026 3,071 Thereafter 10,779 Total future lease payments 26,437 Less imputed interest 7,682 Present value of lease liabilities $ 18,755
Operating Lease Expense	The operating lease expense for the three months ended March 31, 2022 and 2021, were as follows: Three Months Ended March 31, 2022 2021 Operating lease expense $ 848 $ 802

Stock-Based Compensation (Table

Stock-Based Compensation (Tables) - 2008 Equity Incentive Plan	3 Months Ended
	Mar. 31, 2022
Activity Under Equity Incentive Plans Related to Stock Options	Activity under the Company’s equity incentive plans related to stock options is set forth below (in thousands except per share amounts): Number of Weighted Average Balance at December 31, 2021 15,092 $ 5.02 Granted 1,385 5.76 Exercised ( 424 ) 3.79 Forfeited/canceled ( 31 ) 6.15 Balance at March 31, 2022 16,022 5.11
Activity Under Equity Incentive Plans Related to RSUs	Activity under the Company’s equity incentive plans related to RSUs is set forth below (in thousands except per share amounts): Number of Weighted Average Balance at December 31, 2021 6,689 $ 5.90 Granted (1) 4,097 5.77 Vested (1) ( 2,597 ) 5.66 Forfeited (1) ( 67 ) 5.94 Balance at March 31, 2022 8,122 5.91 (1) Includes shares issuable under performance-based restricted stock unit awards.

Segment, Customer and Geograp_2

Segment, Customer and Geographic Information (Tables)	3 Months Ended
Segment, Customer and Geographic Information (Tables)	Mar. 31, 2022
Segment Reporting [Abstract]
Customer that Accounted for More Than Ten Percent of Total Product Revenue	The Company had the following significant customers that accounted for more than 10% of the Company’s total product revenue, during the three months ended March 31, 2022 and 2021(in percentage): Three Months Ended March 31 2022 2021 American Red Cross 35 % 22 % Établissement Français du Sang 13 % 22 %

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Detail)	1 Months Ended	3 Months Ended		12 Months Ended
	Feb. 28, 2021	Mar. 31, 2022USD ($)SegmentCustomer	Mar. 31, 2021USD ($)	Dec. 31, 2021USD ($)Customer
Summary Of Significant Accounting Policies [Line Items]
Net cash used in operating activities		$ (21,456,000)	$ (17,455,000)
Description of payment of customer invoice contract		The Company invoices its customers based upon the terms in the contracts, which generally requires payment 30 to 60 days from the date of invoice.
Application of an optional exemption not to disclose the value of unsatisfied performance obligations		true
Number of major customers representing outstanding accounts receivable \| Customer		3		2
Inventory valuation reserves		$ 400,000
Number of reportable segments \| Segment		1
Period of warranty		1 year
Warranty claim liability		$ 0		$ 0
Cerus Zhongbaokang Shandong Biomedical Co L T D \| China
Summary Of Significant Accounting Policies [Line Items]
Variable interest entity, Purpose of VIE		the Company entered into an Equity Joint Venture Contract with Shandong Zhongbaokang Medical Implements Co., Ltd., or ZBK, to establish Cerus Zhongbaokang (Shandong) Biomedical Co., LTD., or the JV, for the purpose of developing, obtaining regulatory approval for, and eventual manufacturing and commercialization of the INTERCEPT blood transfusion for platelets and red blood cells in the People’s Republic of China.
Ownership percentage	51.00%
Noncontrolling interest in variable interest entity				$ 1,000,000
Trade Accounts Receivable \| Customer Concentration Risk \| Customers
Summary Of Significant Accounting Policies [Line Items]
Concentration risk, percentage		63.00%		48.00%
Other Assets
Summary Of Significant Accounting Policies [Line Items]
Cash surrender value of associated life insurance policies		$ 1,900,000		$ 1,100,000
Other Non-current Liabilities
Summary Of Significant Accounting Policies [Line Items]
Liability for deferred compensation		$ 2,000,000		1,200,000
Minimum
Summary Of Significant Accounting Policies [Line Items]
Payment of customer invoice contract period		30 days
Shelf lives of inventory		18 months
Estimated useful life of property and equipment		3 years
Maximum
Summary Of Significant Accounting Policies [Line Items]
Payment of customer invoice contract period		60 days
Percentage of deferred compensation from base salary		80.00%
Percentage of deferred compensation from variable compensation		100.00%
Shelf lives of inventory		24 months
Inventory valuation reserves				200,000
Estimated useful life of property and equipment		5 years
Product
Summary Of Significant Accounting Policies [Line Items]
Contract asset		$ 0		$ 0
Immaterial Correction of an Error
Summary Of Significant Accounting Policies [Line Items]
Net cash used in operating activities			$ 500,000

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Summary of Product Revenue by Geographical Locations of Customers (Detail) - Product - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Disaggregation Of Revenue [Line Items]
Total product revenue	$ 37,444	$ 23,379
North America
Disaggregation Of Revenue [Line Items]
Total product revenue	22,198	9,664
Europe, Middle East and Africa
Disaggregation Of Revenue [Line Items]
Total product revenue	14,802	13,277
Other
Disaggregation Of Revenue [Line Items]
Total product revenue	$ 444	$ 438

Potential Shares, Excluded from

Potential Shares, Excluded from Calculation of Weighted Average Number of Shares Outstanding used for Calculation of Diluted Net Loss Per Share (Detail) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted average number of anti-dilutive potential shares	23,087	23,077
Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted average number of anti-dilutive potential shares	15,377	16,656
Restricted Stock Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted average number of anti-dilutive potential shares	7,670	6,377
Employee Stock Purchase Plan Rights
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted average number of anti-dilutive potential shares	40	44

Summary of Available-for-Sale S

Summary of Available-for-Sale Securities (Detail) - USD ($)	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 83,007,000	$ 87,919,000
Gross Unrealized Gain	10,000	106,000
Gross Unrealized Loss	(1,645,000)	(255,000)
Allowance for Credit Loss	0	0	$ 0
Fair Value	81,372,000	87,770,000
Money market funds
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	11,187,000	7,170,000
Gross Unrealized Gain	0	0
Gross Unrealized Loss	0	0
Allowance for Credit Loss	0	0
Fair Value	11,187,000	7,170,000
United States government agency securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	20,757,000	25,761,000
Gross Unrealized Gain	0	1,000
Gross Unrealized Loss	(506,000)	(77,000)
Allowance for Credit Loss	0	0
Fair Value	20,251,000	25,685,000
Corporate debt securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	48,574,000	52,611,000
Gross Unrealized Gain	8,000	105,000
Gross Unrealized Loss	(1,039,000)	(156,000)
Allowance for Credit Loss	0	0
Fair Value	47,543,000	52,560,000
Mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	2,489,000	2,377,000
Gross Unrealized Gain	2,000	0
Gross Unrealized Loss	(100,000)	(22,000)
Allowance for Credit Loss	0	0
Fair Value	$ 2,391,000	$ 2,355,000

Available-for-Sale Debt Securit

Available-for-Sale Debt Securities by Original Contractual Maturity (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Investments Debt And Equity Securities [Abstract]
One year or less, amortized cost	$ 40,197	$ 44,873
Greater than one year and less than five years, amortized cost	42,810	43,046
Amortized Cost	83,007	87,919
One year or less, fair value	40,113	44,952
Greater than one year and less than five years, fair value	41,259	42,818
Total available-for-sale securities fair value	$ 81,372	$ 87,770

Available-for-Sale Marketable S

Available-for-Sale Marketable Securities in Unrealized Position (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months, Fair Value	$ 63,897	$ 48,631
Less than 12 Months, Unrealized Loss	(1,645)	(250)
12 Months or Longer, Fair Value	0	2,017
12 Months or Longer, Unrealized Loss	0	(5)
Total, Fair Value	63,897	50,648
Total, Unrealized Loss	(1,645)	(255)
Corporate debt securities
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months, Fair Value	41,507	27,909
Less than 12 Months, Unrealized Loss	(1,039)	(153)
12 Months or Longer, Fair Value	0	998
12 Months or Longer, Unrealized Loss	0	(3)
Total, Fair Value	41,507	28,907
Total, Unrealized Loss	(1,039)	(156)
United States government agency securities
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months, Fair Value	20,251	18,367
Less than 12 Months, Unrealized Loss	(506)	(75)
12 Months or Longer, Fair Value	0	1,019
12 Months or Longer, Unrealized Loss	0	(2)
Total, Fair Value	20,251	19,386
Total, Unrealized Loss	(506)	(77)
Mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months, Fair Value	2,139	2,355
Less than 12 Months, Unrealized Loss	(100)	(22)
12 Months or Longer, Fair Value	0	0
12 Months or Longer, Unrealized Loss	0	0
Total, Fair Value	2,139	2,355
Total, Unrealized Loss	$ (100)	$ (22)

Available-for-sale Securities_3

Available-for-sale Securities and Fair Value on Financial Instruments - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Schedule of Available-for-sale Securities [Line Items]
Credit losses recognized	$ 0	$ 0	$ 0
Gross realized gains from the sale or maturity of available-for-sale investments	0	0
Gross realized losses from the sale or maturity of available-for-sale investments	$ 0	$ 0

Fair Values on Financial Assets

Fair Values on Financial Assets and Liabilities (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Fair value of financial assets and liabilities
Total financial assets	$ 81,662	$ 88,340
Money market funds
Fair value of financial assets and liabilities
Total short-term investments	11,187	7,170
Short-term Investments
Fair value of financial assets and liabilities
Total short-term investments	81,372	87,770
United States government agency securities \| Short-term Investments
Fair value of financial assets and liabilities
Total short-term investments	20,251	25,685
Corporate debt securities \| Short-term Investments
Fair value of financial assets and liabilities
Total short-term investments	47,543	52,560
Mortgage-backed securities \| Short-term Investments
Fair value of financial assets and liabilities
Total short-term investments	2,391	2,355
Warrant \| Other Assets
Fair value of financial assets and liabilities
Warrants	290	570
Level 1
Fair value of financial assets and liabilities
Total financial assets	11,187	7,170
Level 1 \| Money market funds
Fair value of financial assets and liabilities
Total short-term investments	11,187	7,170
Level 1 \| Short-term Investments
Fair value of financial assets and liabilities
Total short-term investments	11,187	7,170
Level 2
Fair value of financial assets and liabilities
Total financial assets	70,185	80,600
Level 2 \| Short-term Investments
Fair value of financial assets and liabilities
Total short-term investments	70,185	80,600
Level 2 \| United States government agency securities \| Short-term Investments
Fair value of financial assets and liabilities
Total short-term investments	20,251	25,685
Level 2 \| Corporate debt securities \| Short-term Investments
Fair value of financial assets and liabilities
Total short-term investments	47,543	52,560
Level 2 \| Mortgage-backed securities \| Short-term Investments
Fair value of financial assets and liabilities
Total short-term investments	2,391	2,355
Level 3
Fair value of financial assets and liabilities
Total financial assets	290	570
Level 3 \| Warrant \| Other Assets
Fair value of financial assets and liabilities
Warrants	$ 290	$ 570

Summary of Gain Recognized in C

Summary of Gain Recognized in Condensed Consolidated Statements of Operations Due to Changes in Fair Value of Warrant (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Warrant \| Level 3
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
(Loss) gain from changes in the fair value of level 3 investments	$ (280)	$ 220

Inventories, net (Detail)

Inventories, net (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Inventory Disclosure [Abstract]
Raw materials	$ 13,939	$ 15,664
Work-in-process	5,289	5,044
Finished goods	24,418	22,129
Total inventories	43,646	42,837
Less: non-current inventories	15,125	16,044
Total current inventories	$ 28,521	$ 26,793

Accrued Liabilities (Detail)

Accrued Liabilities (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Payables And Accruals [Abstract]
Accrued compensation and related costs	$ 10,673	$ 18,506
Accrued professional services	3,004	3,942
Other accrued expenses	3,271	3,225
Total accrued liabilities	$ 16,948	$ 25,673

Debt (Detail)

Debt (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Debt Instrument [Line Items]
Less: current portion of term loan	$ (15,011)	$ (14,697)
Non-current portion of term loan	54,769	54,724
Term Loan Credit Agreement
Debt Instrument [Line Items]
Total term loan, Principal	55,000	55,000
Total term loan, Unamortized Discount	(231)	(276)
Total term loan	54,769	54,724
Non-current portion of term loan, Principal	55,000	55,000
Non-current portion of term loan, Unamortized Discount	(231)	(276)
Non-current portion of term loan	$ 54,769	$ 54,724

Debt - Expected Principal, Inte

Debt - Expected Principal, Interest and Fee Payments on Term Loan Credit Agreement (Detail) - Term Loan Credit Agreement - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Debt Instrument [Line Items]
2023, Principal	$ 41,250
2024, Principal	13,750
Total, Principal	55,000	$ 55,000
2022 Interest and Fees	3,151
2023, Interest and Fees	3,134
2024, Interest and Fees	1,826
Total, Interest and Fees	8,111
2022 Total	3,151
2023, Total	44,384
2024, Total	15,576
Total	$ 63,111

Debt - Additional Information (

Debt - Additional Information (Detail)	Mar. 29, 2019USD ($)Tranche	Mar. 31, 2022USD ($)	Dec. 31, 2021USD ($)
Term Loan Credit Agreement
Debt Instrument [Line Items]
Term loan, face amount	$ 70,000,000
Number of loan tranches \| Tranche	3
Debt instrument maturity date	Mar. 1, 2024
Term Loan Credit Agreement \| Two Thousand Nineteen Term Loan
Debt Instrument [Line Items]
Debt instrument floating interest rate percentage	1.80%
Effective interest rate		7.50%
Interest-only payments date	Mar. 1, 2023
Principal plus declining interest payments	12 months
Term Loan Credit Agreement \| Tranche 1
Debt Instrument [Line Items]
Term loan, face amount	$ 40,000,000
Term Loan Credit Agreement \| Tranche 2 \| Two Thousand Nineteen Term Loan
Debt Instrument [Line Items]
Term loan, face amount	$ 15,000,000
Term Loan Credit Agreement \| Tranche 3 \| Two Thousand Nineteen Term Loan
Debt Instrument [Line Items]
Debt instrument maturity date	Dec. 31, 2021
Loan and security agreement available upon revenue achievement	$ 15,000,000
Revolving Loan Credit Agreement
Debt Instrument [Line Items]
Term loan, face amount		$ 15,000,000	$ 14,700,000
Loan and security agreement available upon revenue achievement	$ 5,000,000
Debt instrument floating interest rate percentage	1.80%
Borrowing limit	$ 15,000,000
Revolving Loan Credit Agreement \| Two Thousand Nineteen Term Loan
Debt Instrument [Line Items]
Debt instrument maturity date	Mar. 1, 2024

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2022USD ($)
Commitments And Contingencies Disclosure [Abstract]
Minimum term of non-cancellable operating leases	1 year
Expiration of non-cancellable operating leases maximum year	2030
Operating lease not yet commenced	the Company had no leases that have not yet commenced.
Short-term purchase commitments	$ 23.4
Long-term purchase commitments	$ 2.7

Commitments and Contingencies_2

Commitments and Contingencies - Supplemental Cash Flow Information Related to Operating Leases (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Commitments And Contingencies Disclosure [Abstract]
Cash payments for operating leases	$ 910	$ 1,000
Right-of-use assets obtained in exchange for operating lease obligations	$ 1,315	$ 41
Weighted-average remaining lease term	7 years 1 month 6 days	8 years 3 months 18 days
Weighted-average discount rate	8.30%	9.00%

Commitments and Contingencies_3

Commitments and Contingencies - Future Minimum Non-Cancelable Lease Payments Under Operating Leases (Detail) $ in Thousands	Mar. 31, 2022USD ($)
Commitments And Contingencies Disclosure [Abstract]
2022 (remainder)	$ 2,535
2023	3,519
2024	3,418
2025	3,115
2026	3,071
Thereafter	10,779
Total future lease payments	26,437
Less imputed interest	7,682
Present value of lease liabilities	$ 18,755

Commitments and Contingencies_4

Commitments and Contingencies - Operating Lease Expense (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Commitments And Contingencies Disclosure [Abstract]
Operating lease expense	$ 848	$ 802

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail) - Cantor Fitzgerald & Co. and Stifel, Nicolaus & Company, Incorporated - Amendment No. 3 - Sales Agreements - USD ($)	Dec. 11, 2020	Mar. 31, 2022
Stockholders Equity Note [Line Items]
Maximum common stock offering price	$ 100,000,000
Percentage of proceeds payable as compensation to underwriter	2.00%
Issuance of common stock from public offerings, net of offering costs (in shares)		0
Common stock available to be sold		$ 96,800,000

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) $ in Millions	1 Months Ended			3 Months Ended
	Jun. 30, 2021shares	Jun. 30, 2020shares	Jun. 30, 2019shares	Mar. 31, 2022USD ($)Periodshares	Dec. 31, 2021shares
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation, option to be granted at percentage of fair value of common stock				85.00%
Employee Stock Purchase Plan, offering period				12 months
Number of purchase periods within each offering period \| Period				2
Increase in shares of common stock authorized for issuance		1,500,000
Aggregate number of shares of common stock reserved for future issuance				1,500,000
2008 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation, option to be granted at percentage of fair value of common stock				100.00%
Increase in shares of common stock authorized for issuance	7,600,000	5,000,000	11,800,000
Aggregate number of shares of common stock reserved for future issuance				27,500,000
Stock-based compensation, award term				10 years
Performance-based stock options, outstanding				1,400,000
Outstanding options and other stock based awards				16,022,000	15,092,000
Number of shares available for future issuance				3.4
2008 Equity Incentive Plan \| Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation, vesting period				4 years
2008 Equity Incentive Plan \| Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of unvested Restricted Stock Units				8,122,000	6,689,000
2008 Equity Incentive Plan \| Performance-based Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee Stock Purchase Plan, authorized shares for issuance				500,000
2008 Equity Incentive Plan \| Performance-based Cash Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option plan granted on cash award \| $				$ 1
2008 Equity Incentive Plan \| Minimum \| Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation, vesting period				3 years
2008 Equity Incentive Plan \| Maximum \| Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation, vesting period				4 years

Activity Under Equity Incentive

Activity Under Equity Incentive Plans Related to Stock Options (Detail) - 2008 Equity Incentive Plan shares in Thousands	3 Months Ended
	Mar. 31, 2022$ / sharesshares
Activity under the Company's equity incentive plans related to stock options
Number of Options Outstanding, Beginning Balance \| shares	15,092
Granted, Number of Options Outstanding \| shares	1,385
Exercised, Number of Options Outstanding \| shares	(424)
Forfeited/canceled, Number of Options Outstanding \| shares	(31)
Number of Options Outstanding, Ending Balance \| shares	16,022
Weighted Average Exercise Price per Share
Weighted Average Exercise Price per Share, Beginning Balance \| $ / shares	$ 5.02
Granted, Weighted Average Exercise Price per Share \| $ / shares	5.76
Exercised, Weighted Average Exercise Price per Share \| $ / shares	3.79
Forfeited/canceled, Weighted Average Exercise Price per Share \| $ / shares	6.15
Weighted Average Exercise Price per Share, Ending Balance \| $ / shares	$ 5.11

Activity Under Equity Incenti_2

Activity Under Equity Incentive Plans Related to RSUs (Detail) - 2008 Equity Incentive Plan - Restricted Stock Units shares in Thousands	3 Months Ended
	Mar. 31, 2022$ / sharesshares
Activity under the Company's equity incentive plans related to restricted stock units
Number of Restricted Stock Units Unvested, Beginning Balance \| shares	6,689
Granted, Number of Restricted Stock Units Unvested \| shares	4,097	[1]
Vested, Number of Restricted Stock Units Unvested \| shares	(2,597)	[1]
Forfeited, Number of Restricted Stock Units Unvested \| shares	(67)	[1]
Number of Restricted Stock Units Unvested, Ending Balance \| shares	8,122
Weighted Average Exercise Price per Share
Weighted Average Exercise Price per Share, Beginning Balance \| $ / shares	$ 5.90
Granted, Weighted Average Exercise Price per Share \| $ / shares	5.77	[1]
Vested, Weighted Average Exercise Price per Share \| $ / shares	5.66	[1]
Forfeited, Weighted Average Exercise Price per Share \| $ / shares	5.94	[1]
Weighted Average Exercise Price per Share, Ending Balance \| $ / shares	$ 5.91

[1]	Includes shares issuable under performance-based restricted stock unit awards.

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Income Tax Disclosure [Line Items]
Income tax expense (benefit)	$ 76	$ 98
Cerus Europe B.V.
Income Tax Disclosure [Line Items]
Income tax expense (benefit)	$ 100	$ 100

Development and License Agree_2

Development and License Agreements - Additional Information (Detail) - USD ($)	1 Months Ended	3 Months Ended
	Sep. 30, 2020	Mar. 31, 2022	Dec. 31, 2021	Jun. 30, 2021
BARDA Agreement
Licenses Agreements [Line Items]
Additional committed fund receivable				$ 9,600,000
Committed fund receivable		$ 126,500,000
Committed fund receivable		223,500,000
Accounts receivable of billed and unbilled amounts		4,600,000	$ 4,700,000
BARDA Agreement \| Cerus Corporation \| Maximum
Licenses Agreements [Line Items]
Co-investment by the company		9,600,000
FDA Agreement
Licenses Agreements [Line Items]
Accounts receivable of billed and unbilled amounts		$ 300,000	$ 200,000
Contract agreement term	5 years
Total potential contract value	$ 11,100,000

Segment, Customer and Geograp_3

Segment, Customer and Geographic Information - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2022Segment
Segment Reporting [Abstract]
Number of operating segments	1

Segment, Customer and Geograp_4

Segment, Customer and Geographic Information - Significant Customer that Accounted for More than Ten Percentage of Total Product Revenue (Detail) - Customer Concentration Risk - Sales Revenue, Goods, Net	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
American Red Cross
Revenue, Major Customer [Line Items]
Concentration risk, percentage	35.00%	22.00%
Etablissement Francais du Sang
Revenue, Major Customer [Line Items]
Concentration risk, percentage	13.00%	22.00%

Subsequent Event - Additional I

Subsequent Event - Additional Information (Detail)	1 Months Ended
Subsequent Event - Additional Information (Detail)	May 31, 2022
Subsequent Event \| Fresenius
Subsequent Event [Line Items]
Contract extension period	10 years