MBX Biosciences, Inc. Common Stock (MBX) SC 13DMBX Biosciences / New Enterprise Associates 17 ownership change

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No.    )*

MBX Biosciences, Inc.

(Name of Issuer)

Common Stock, $0.0001 par value per share

(Title of Class of Securities)

55287L101

(CUSIP Number)

Stephanie Brecher

New Enterprise Associates

1954 Greenspring Drive, Suite 600

Timonium, MD 21093

(410) 842-4000

(Name, Address and Telephone Number of Person

Authorized to Receive Notices and Communications)

September 16, 2024

(Date of Event which Requires Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box. ☐

Note:  Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See §240.13d-7 for other parties to whom copies are to be sent.

*The remainder of this cover page shall be filled out for a reporting person’s initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

Item 1. Security and Issuer.

This Schedule 13D relates to the common stock, $0.0001 par value per share (“Common Stock”), of MBX Biosciences, Inc. (the “Issuer”), having its principal executive office at 11711 N. Meridian Street, Carmel, IN 46032.

Item 2. Identity and Background.

This statement is being filed by:

(a) New Enterprise Associates 17, L.P. (“NEA 17”); NEA Partners 17, L.P. (“NEA Partners 17”), which is the sole general partner of NEA 17; and NEA 17 GP, LLC (“NEA 17 LLC” and, together with NEA Partners 17, the “Control Entities”), which is the sole general partner of NEA Partners 17; and

(b) Forest Baskett (“Baskett”), Ali Behbahani (“Behbahani”), Carmen Chang (“Chang”), Anthony A. Florence, Jr. (“Florence”), Mohamad H. Makhzoumi (“Makhzoumi”), Edward T. Mathers (“Mathers”), Scott D. Sandell (“Sandell”), Paul Walker (“Walker”) and Rick Yang (“Yang”) (together, the “Managers”). The Managers are the managers of NEA 17 LLC.

The persons named in this Item 2 are referred to individually herein as a “Reporting Person” and collectively as the “Reporting Persons.”

The address of the principal business office of NEA 17, each Control Entity and Sandell is New Enterprise Associates, 1954 Greenspring Drive, Suite 600, Timonium, MD 21093. The address of the principal business office of Baskett, Behbahani, Chang, Makhzoumi, Walker and Yang is New Enterprise Associates, 2855 Sand Hill Road, Menlo Park, CA 94025. The address of the principal business office of Florence and Mathers is New Enterprise Associates, 104 5^th Avenue, 19^th Floor, New York, NY 10011.

The principal business of NEA 17 is to invest in and assist growth-oriented businesses located principally in the United States. The principal business of NEA Partners 17 is to act as the sole general partner of NEA 17. The principal business of NEA 17 LLC is to act as the sole general partner of NEA Partners 17. The principal business of each of the Managers is to manage the Control Entities and a number of affiliated partnerships with similar businesses.

During the five years prior to the date hereof, none of the Reporting Persons has been convicted in a criminal proceeding or has been a party to a civil proceeding ending in a judgment, decree or final order enjoining future violations of, or prohibiting or mandating activities subject to, federal or state securities laws or finding any violation with respect to such laws.

NEA 17 LLC is a limited liability company organized under the laws of the State of Delaware. NEA 17 and NEA Partners 17 are limited partnerships organized under the laws of the State of Delaware. Each of the Managers is a United States citizen.

Item 3. Source and Amount of Funds or Other Consideration.

On September 12, 2024, the Registration Statement on Form S-1 filed with the Securities and Exchange Commission (the “SEC”) by the Issuer (File No. 333-281764) in connection with its initial public offering of 10,200,000 shares of Common Stock of the Issuer (the “IPO”) was declared effective. The closing of the IPO took place on September 16, 2024 (the “Closing”), and in connection with the Closing, NEA 17 purchased an aggregate of 500,000 shares of the Issuer’s Common Stock at the IPO price of $16.00 per share.

Prior to the Closing, NEA 17 purchased from the Issuer in a series of private transactions, 12,299,854 shares of Series A Convertible Preferred Stock (“NEA 17 Series A Stock”) and 25,142,840 shares of Series B Convertible Preferred Stock (“NEA 17 Series B Stock”) for an aggregate purchase price of $30,815,700.35. Immediately prior to the Closing, the shares of NEA 17 Series A Stock and NEA 17 Series B Stock held by NEA 17 automatically converted into 3,114,486 shares of Common Stock of the Issuer on a one-for-12.0221 basis. NEA 17 now holds a total of 3,614,486 shares of Common Stock (the “NEA 17 Shares”).

Item 4. Purpose of Transaction.

NEA 17 acquired the NEA 17 Shares for investment purposes. Depending on market conditions, its continuing evaluation of the business and prospects of the Issuer and other factors, NEA 17 and other Reporting Persons may dispose of or acquire additional shares of the Issuer. Except as set forth above, none of the Reporting Persons has any present plans which relate to or would result in:

Item 5. Interest in Securities of the Issuer.

Each Reporting Person disclaims beneficial ownership of the NEA 17 Shares other than those shares which such person owns of record.

The percentage of outstanding Common Stock of the Issuer which may be deemed to be beneficially owned by each Reporting Person is set forth on Line 13 of such Reporting Person’s cover sheet. Such percentage was calculated based on the 31,853,698 shares of Common Stock reported by the Issuer to be outstanding immediately following the IPO on the Issuer’s Prospectus filed under Rule 424(b)(5), filed with the Securities and Exchange Commission on September 12, 2024.

Item 6. Contracts, Arrangements, Understandings or Relationships with Respect to Securities of the Issuer.

NEA 17 has entered into a lock-up agreement with the underwriters in connection with the IPO whereby NEA 17 has generally agreed, subject to certain exceptions, that for a period of 180 days after September 12, 2024, it will not (and may not cause any of its direct or indirect affiliates to), without the prior written consent of J.P. Morgan Securities LLC and Jeffries LLC, (1) offer, pledge, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant to purchase, lend or otherwise transfer or dispose of, directly or indirectly, any shares of Common Stock or any securities convertible into or exercisable or exchangeable for Common Stock (including, without limitation, Common Stock or such other securities which may be deemed to be beneficially owned by such lock-up parties in accordance with the rules and regulations of the SEC and securities which may be issued upon exercise of a stock option or warrant), (2) enter into any hedging, swap or other agreement or transaction that transfers, in whole or in part, any of the economic consequences of ownership of the lock-up securities, whether any such transaction described in clause (1) or (2) above is to be settled by delivery of lock-up securities, in cash or otherwise, (3) make any demand for, or exercise any right with respect to, the registration of any lock-up securities, or (4) publicly disclose the intention to do any of the foregoing.

Item 7. Material to be Filed as Exhibits.

Exhibit 1 – Agreement regarding filing of joint Schedule 13D.

Exhibit 2 – Power of Attorney regarding filings under the Securities Exchange Act of 1934, as amended.

SIGNATURE

After reasonable inquiry and to the best of its knowledge and belief, each of the undersigned certifies that the information set forth in this statement is true, complete and correct.

EXECUTED this 23^rd day of September, 2024.

NEW ENTERPRISE ASSOCIATES 17, L.P.

  By:                             *                                

 Anthony A. Florence, Jr.

 Managing Partner and Co-Chief Executive Officer 

  By:                             *                                

 Mohamad Makhzoumi

 Managing Partner and Co-Chief Executive Officer 

NEA PARTNERS 17, L.P.

  By:                             *                                

 Anthony A. Florence, Jr.

 Managing Partner and Co-Chief Executive Officer 

  By:                             *                                

 Mohamad Makhzoumi

 Managing Partner and Co-Chief Executive Officer 

NEA 17 GP, LLC

By:                             *                                

Anthony A. Florence, Jr.

Managing Partner and Co-Chief Executive Officer 

By:                             *                                

Mohamad Makhzoumi

Managing Partner and Co-Chief Executive Officer 

                 *                        

Forest Baskett

                 *                        

Ali Behbahani

                 *                        

Carmen Chang

                 *                        

Anthony A. Florence, Jr.

                 *                        

Mohamad H. Makhzoumi

                 *                        

Edward T. Mathers

                 *                        

Scott D. Sandell

                 *                        

Paul Walker

                 *                        

Rick Yang

*/s/ Zachary Bambach           

Zachary Bambach

As attorney-in-fact

This Schedule 13D was executed by Zachary Bambach on behalf of the individuals listed above pursuant to a Powers of Attorney, a copy of which is attached as Exhibit 2.

EXHIBIT 1

AGREEMENT

Pursuant to Rule 13d-1(k)(1) under the Securities Exchange Act of 1934, the undersigned hereby agree that only one statement containing the information required by Schedule 13D need be filed with respect to the ownership by each of the undersigned of shares of stock of MBX Biosciences, Inc.

EXECUTED this 23^rd day of September, 2024.

NEW ENTERPRISE ASSOCIATES 17, L.P.

  By:                             *                                

 Anthony A. Florence, Jr.

 Managing Partner and Co-Chief Executive Officer 

  By:                             *                                

 Mohamad Makhzoumi

 Managing Partner and Co-Chief Executive Officer 

NEA PARTNERS 17, L.P.

  By:                             *                                

 Anthony A. Florence, Jr.

 Managing Partner and Co-Chief Executive Officer 

  By:                             *                                

 Mohamad Makhzoumi

 Managing Partner and Co-Chief Executive Officer  

NEA 17 GP, LLC

By:                             *                                

Anthony A. Florence, Jr.

Managing Partner and Co-Chief Executive Officer 

By:                             *                                

Mohamad Makhzoumi

Managing Partner and Co-Chief Executive Officer 

                 *                        

Forest Baskett

                 *                        

Ali Behbahani

                 *                        

Carmen Chang

                 *                        

Anthony A. Florence, Jr.

                 *                        

Mohamad H. Makhzoumi

                 *                        

Edward T. Mathers

                 *                        

Scott D. Sandell

                 *                        

Paul Walker

                 *                        

Rick Yang

*/s/ Zachary Bambach           

Zachary Bambach

As attorney-in-fact

This Schedule 13D was executed by Zachary Bambach on behalf of the individuals listed above pursuant to a Powers of Attorney, a copy of which is attached as Exhibit 2.

EXHIBIT 2

POWER OF ATTORNEY

KNOW ALL MEN BY THESE PRESENTS, that the undersigned hereby constitutes and appoints Zachary Bambach, Nicole Hatcher and Stephanie Brecher, and each of them, with full power to act without the others, his or her true and lawful attorney-in-fact, with full power of substitution, to sign any and all instruments, certificates and documents that may be necessary, desirable or appropriate to be executed on behalf of himself as an individual or in his or her capacity as a direct or indirect general partner, director, officer or manager of any partnership, corporation or limited liability company, pursuant to section 13 or 16 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and any and all regulations promulgated thereunder, including, without limitation, Forms 3, 4 and 5 and Schedules 13D and 13G (and any amendments thereto), and to file the same, with all exhibits thereto, and any other documents in connection therewith, with the Securities and Exchange Commission (the “SEC”), including, but not limited to, signing a Form ID for and on behalf of the undersigned and filing such Form ID with the SEC, and with any other entity when and if such is mandated by the Exchange Act or by the Financial Industry Regulatory Authority, granting unto said attorney-in-fact full power and authority to do and perform each and every act and thing necessary, desirable or appropriate, fully to all intents and purposes as he or she might or could do in person, thereby ratifying and confirming all that said attorney-in-fact, or his or her substitutes, may lawfully do or cause to be done by virtue hereof. This power of attorney is perpetual, unless revoked by the undersigned in a signed writing delivered to each of the foregoing attorneys-in-fact.

IN WITNESS WHEREOF, this Power of Attorney has been signed as of the 29th day of February, 2024.