HLVX S-8 Amendment: 9.46M Shares Reserved for Incentive and ESPP

Rhea-AI Filing Summary

HilleVax, Inc. filed a post-effective amendment to register a total of 9,460,039 shares of its common stock for issuance under employee equity plans. The filing specifically registers 8,200,000 shares reserved under the 2022 Incentive Award Plan, 200,039 shares subject to outstanding options under the 2021 Equity Incentive Plan, and 1,060,000 shares reserved under the 2022 Employee Stock Purchase Plan. The document identifies the company as incorporated in Delaware and shows the principal executive office in Boston, Massachusetts, with Owen Hughes signing on behalf of the company.

Positive

• 9,460,039 total shares explicitly registered for issuance under employee equity plans, providing clarity on share availability
• Specific plan allocations are disclosed: 8,200,000 for the 2022 Incentive Award Plan, 200,039 for outstanding options under the 2021 Equity Incentive Plan, and 1,060,000 for the 2022 ESPP
• Filing executed by company officer (Owen Hughes), confirming corporate authorization of the registration

Negative

• Registration permits issuance of up to 9,460,039 additional shares, which could increase the number of shares outstanding
• No timing or issuance details are provided in the filing, so investors cannot assess when or how many registered shares will actually be issued

Insights

Compensation & Equity Plan Analyst

TL;DR: HilleVax registered 9.46M shares for employee equity plans, enabling planned equity issuance for compensation and employee purchase programs.

The registration statement confirms the company has made available 8,200,000 shares for its 2022 Incentive Award Plan, 200,039 shares tied to outstanding options under the 2021 plan, and 1,060,000 shares for the 2022 Employee Stock Purchase Plan. This is a routine administrative SEC filing to permit issuance of shares under established employee plans. The filing does not include financial metrics, timing for issuance, or dilution schedules. From an equity-compensation perspective, the registered share totals are explicit and provide clarity on the maximum number of shares that may be issued under these programs.

Corporate Governance Specialist

TL;DR: The S-8 post-effective amendment documents standard corporate housekeeping to register shares for employee plans; it is procedural and non-financial in nature.

The document identifies corporate details (Delaware incorporation, Boston principal office) and confirms officer execution. It solely addresses registration of shares reserved for employee incentive and purchase plans and does not disclose governance changes, material transactions, or financial impacts. As such, the filing is administrative and holds limited standalone material impact for investors beyond clarifying the pool of shares available for employee-related issuance.

As filed with the Securities and Exchange Commission on September 17, 2025

Registration No. 333-264590

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

POST-EFFECTIVE AMENDMENT NO. 1 TO

FORM S-8 REGISTRATION STATEMENT

(REGISTRATION NO. 333-264590)

UNDER

THE SECURITIES ACT OF 1933

HILLEVAX, INC.

(Exact name of registrant as specified in its charter)

Delaware		85-0545060
(State or other jurisdiction of incorporation or organization)		(I.R.S. Employer Identification No.)
321 Harrison Avenue Boston, Massachusetts		02118
(Address of Principal Executive Offices)		(Zip Code)

HILLEVAX, INC. 2021 EQUITY INCENTIVE PLAN

HILLEVAX, INC. 2022 INCENTIVE AWARD PLAN

HILLEVAX, INC. 2022 EMPLOYEE STOCK PURCHASE PLAN

(Full title of the plans)

Robert Hershberg, M.D., Ph.D.

Chairman, President and Chief Executive Officer

HilleVax, Inc.

321 Harrison Avenue

Boston, Massachusetts 02118

(Name and address of agent for service)

(617) 213-5054

(Telephone number, including area code, of agent for service)

Copies to:

Matthew T. Bush

Daniel E. Rees

Cheston J. Larson

Latham & Watkins LLP

200 Clarendon Street

Boston, Massachusetts 02116

(617) 948-6000

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

Large accelerated filer		☐		Accelerated filer		☐
Non-accelerated filer		☒		Smaller reporting company		☒
				Emerging growth company		☒

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act. ☐

DEREGISTRATION OF SECURITIES

This Post-Effective Amendment No. 1 relates to the following registration statement on Form S-8 filed with the Securities and Exchange Commission (the “SEC”) by HilleVax, Inc., a Delaware corporation (the “Registrant”):

• registration statement on Form S-8 (Registration No. 333-264590) filed with the SEC on April 29, 2022, pertaining to the registration of (i) 8,200,000 shares of the common stock of the Registrant, $0.0001 par value per share (the “Common Stock”), reserved for issuance under the Registrant 2022 Incentive Award Plan, (ii) 200,039 shares of Common Stock subject to outstanding options under the Registrant 2021 Equity Incentive Plan, and (iii) 1,060,000 shares of Common Stock reserved for issuance under the Registrant 2022 Employee Stock Purchase Plan (the “Registration Statement”).

On September 17, 2025, pursuant to the terms of an Agreement and Plan of Merger, dated as of August 4, 2025 (as it may be amended or supplemented, the “Merger Agreement”), by and among the Registrant, XOMA Royalty Corporation, a Nevada corporation (“Parent”), and XRA 4 Corp., a Delaware corporation and a wholly owned subsidiary of Parent (“Merger Sub”), Merger Sub merged with and into the Registrant, with the Registrant surviving the merger as a wholly owned subsidiary of Parent (the “Merger”).

As a result of the Merger, the Registrant has terminated any and all offerings of its securities pursuant to the Registration Statement. In accordance with an undertaking made by the Registrant in the Registration Statement to remove from registration, by means of a post-effective amendment, any of the securities registered under the Registration Statement that remain unissued at the termination of the offerings, the Registrant hereby removes from registration all securities registered but unsold under such Registration Statement, if any, as of the date hereof.

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, as amended, the Registrant certifies that it has reasonable grounds to believe that it meets all the requirements for filing on Form S-8 and has duly caused this Post-Effective Amendment No. 1 to the Registration Statement on Form S-8 to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Wilmington, State of Delaware on September 17, 2025.

HILLEVAX, INC.
By:		/s/ Owen Hughes
		Owen Hughes
		President, Treasurer and Secretary

FAQ

What does HLVX's S-8 post-effective amendment register?

The filing registers 9,460,039 shares of common stock for issuance: 8,200,000 under the 2022 Incentive Award Plan, 200,039 subject to outstanding 2021 plan options, and 1,060,000 under the 2022 Employee Stock Purchase Plan.

Does the filing state when the registered shares will be issued?

No. The document registers the shares for issuance but does not provide timing or schedules for when shares will be issued.

Who signed the registration statement for HilleVax (HLVX)?

The filing is signed by Owen Hughes, noted as President, Treasurer and Secretary of HilleVax, Inc.

Where is HilleVax incorporated and where is its principal executive office?

The filing identifies the company as incorporated in Delaware with its principal executive office at 321 Harrison Avenue, Boston, Massachusetts.

Does this filing include financial results or material transactions?

No. The filing only concerns the registration of shares for employee plans and does not include financial metrics or descriptions of material transactions.