[SC TO-C] HilleVax, Inc. Tender Offer Communication

Rhea-AI Filing Summary

XOMA Royalty Corporation ("Parent") and wholly-owned subsidiary XRA 4 Corp. ("Merger Sub") have filed a Schedule TO-C announcing their intent to launch a third-party tender offer to acquire 100 % of the outstanding common shares of HilleVax, Inc. (HLVX). The offer will be effected pursuant to an Agreement and Plan of Merger dated 4 Aug 2025; however, no tender has yet commenced and no price, premium or timing details are disclosed in this preliminary communication.

When the offer begins, the Buyer Entities will file a full Schedule TO and HilleVax will respond with a Schedule 14D-9. Shareholders are advised to await those materials, which will be available free of charge on the SEC’s website. The filing reiterates standard forward-looking-statement cautions and lists numerous risks that could prevent closing, including regulatory approvals, competing bids and litigation.

Positive

• Definitive merger agreement signed, signaling serious intent to acquire all HLVX shares via tender offer.
• SEC filings committed, ensuring forthcoming transparency through Schedule TO and 14D-9 materials.

Negative

• No offer price or consideration disclosed, leaving shareholders unable to assess value.
• Tender offer not yet commenced and subject to multiple conditions and potential termination events.

Insights

M&A Specialist

TL;DR – Early notice of XOMA’s all-cash tender for HLVX; material terms still missing, so valuation impact unclear.

This is a required pre-commencement filing under Rule 14d-2(b). It confirms a definitive merger agreement but withholds key economics—offer price, expected closing window, financing and regulatory hurdles. Until the Schedule TO is filed, investors lack visibility on deal premium or likelihood of completion. The extensive risk language underscores uncertainty. From an arbitrage perspective, there is no spread to play yet, keeping market impact muted.

Equity Analyst

TL;DR – Potential take-out could benefit HLVX holders, but absence of financial terms limits immediate investment action.

HilleVax shareholders may ultimately see a control premium, yet the filing offers no guidance on valuation, financing structure or CVR economics. Without those figures, the news is informational rather than catalytic. The requirement for subsequent SEC filings means clarity will emerge later; near-term trading likely hinges on speculation rather than fundamentals.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE TO

(Rule 14d-100)

TENDER OFFER STATEMENT UNDER SECTION 14(d)(1) OR 13(e)(1)

OF THE SECURITIES EXCHANGE ACT OF 1934

HILLEVAX, INC.

(Name of Subject Company (Issuer))

XOMA ROYALTY CORPORATION

(Name of Filing Persons (Offeror 1))

XRA 4 CORP.

(Name of Filing Persons (Offeror 2))

Common Stock, Par Value $0.0001 Per Share

(Title of Class of Securities)

43157M102

(CUSIP Number of Class of Securities)

Owen Hughes

XOMA Royalty Corporation

2200 Powell Street, Suite 310

Emeryville, California 94608

Tel. (510) 204-7200

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications on Behalf of Filing Persons)

Copies to:

Ryan A. Murr

Branden C. Berns

Gibson, Dunn & Crutcher LLP

One Embarcadero Center Suite 2600

San Francisco, CA 94111

☒ Check the box if the filing relates solely to preliminary communications made before the commencement of a tender offer.

Check the appropriate boxes below to designate any transactions to which the statement relates:

☒ third-party tender offer subject to Rule 14d-1.

☐ issuer tender offer subject to Rule 13e-4.

☐ going-private transaction subject to Rule 13e-3.

☐ amendment to Schedule 13D under Rule 13d-2.

Check the following box if the filing is a final amendment reporting the results of the tender offer. ☐

If applicable, check the appropriate box(es) below to designate the appropriate rule provision(s) relied upon:

☐ Rule 13e-4(i) (Cross-Border Issuer Tender Offer)

☐ Rule 13d-1(d) (Cross-Border Third-Party Tender Offer)

This filing relates solely to preliminary communications made before the commencement of a planned tender offer (the “Offer”) by XOMA Royalty Corporation, a Nevada corporation (“Parent”), and XRA 4 Corp., a Delaware corporation and a wholly owned subsidiary of Parent (“Merger Sub” and together with Parent, the “Buyer Entities”), to purchase all of the issued and outstanding shares of common stock, par value $0.0001 per share (“Shares”), of HilleVax, Inc., a Delaware corporation (“HilleVax”), to be commenced pursuant to the Agreement and Plan of Merger, dated as of August 4, 2025, among Parent, Merger Sub and HilleVax (the “Merger Agreement”).

The press release filed herewith as Exhibit 99.1 is neither an offer to purchase nor a solicitation of an offer to sell securities. The Offer for the Shares described in this filing has not commenced. At the time the Offer is commenced, the Buyer Entities will file a tender offer statement on Schedule TO with the Securities and Exchange Commission (“SEC”), and HilleVax will file a solicitation/recommendation statement on Schedule 14D-9, with respect to the Offer.

Cautionary Note Regarding Forward-Looking Statements

This communication contains forward-looking statements related to the Buyer Entities and HilleVax and the acquisition by the Buyer Entities of HilleVax, including express or implied forward-looking statements about the future operations and performance of HilleVax and Parent. These forward-looking statements are within the meaning of U.S. federal securities laws, including, without limitation, statements regarding the anticipated timing of and closing of the proposed Offer, the merger and related transactions contemplated by the Merger Agreement (collectively referred to as the “transactions”). The words “anticipate,” “approximately,” “look to,” “plan,” “expect,” “may,” “will,” “could” or “should,” the negative of these terms or similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. These statements are based on current plans, estimates and projections. By their very nature, forward-looking statements involve inherent risks and uncertainties, both general and specific. The Buyer Entities caution that a number of important factors, including those described in this communication, could cause actual results to differ materially from those contemplated in any forward-looking statements. Any forward-looking statements in this communication are based on management’s current expectations and beliefs and are subject to a number of risks, uncertainties and important factors that may cause actual events or results to differ materially from those expressed or implied by any forward-looking statements contained in this communication, including, without limitation, the impact of actions of other parties with respect to the transactions; the possibility that competing offers will be made; the outcome of any legal proceedings that have been or could be instituted against the Buyer Entities, HilleVax or their respective directors; the risk that the transactions may not be completed in a timely manner, or at all, which may adversely affect HilleVax’s or Parent’s respective businesses and the price of their respective common stock; the failure to satisfy all of the closing conditions of the transactions contemplated by the Merger Agreement; the occurrence of the events giving rise to payments under the Contingent Value Rights (“CVR”) Agreement; the occurrence of any event, change or other circumstance that could give rise to the termination of the Merger Agreement; the effect of the announcement or pendency of the transactions on HilleVax’s and Parent’s respective businesses and operating results; risks that the transactions may disrupt HilleVax’s or Parent’s respective current plans and business operations; risks related to the diverting of management’s attention from HilleVax’s and Parent’s respective ongoing business operations; general economic and market conditions and the other risks identified in HilleVax’s and Parent’s respective filings with the SEC and subsequent filings with the SEC. Should any risks and uncertainties develop into actual events, these developments could have a material adverse effect on the transactions and/or HilleVax and the Buyer Entities’ ability to successfully complete the transactions and, with respect to any CVR payment amounts, the consideration ultimately paid to HilleVax stockholders (including whether any payments will be payable at all). In addition, unlisted factors may present significant additional obstacles to the realization of forward-looking statements. The Buyer Entities caution investors not to place undue reliance on any forward-looking statements. Any forward-looking statements contained in this communication represent the Buyer Entities’ views only as of the date hereof and should not be relied upon as representing its views as of any subsequent date. The Buyer Entities disclaim any obligation to publicly update or revise any such statements to reflect any change in expectations or in events, conditions or circumstances on which any such statements may be based, or that may affect the likelihood that actual results will differ from those set forth in the forward-looking statements.

Additional Information and Where to Find It

The tender offer for the Shares of HilleVax referenced in this communication has not yet commenced. This communication is for informational purposes only and is neither an offer to purchase nor a solicitation of an offer to sell shares, nor is it a substitute for the tender offer materials that the Buyer Entities will file with the SEC. At the time the tender offer is commenced, the Buyer Entities will file tender offer materials on Schedule TO, and, thereafter, HilleVax will file a Solicitation/Recommendation Statement on Schedule 14D-9 with the SEC with respect to the tender offer. The Offer will be made only pursuant to the tender offer materials (including an offer to purchase, a related letter of transmittal and certain other tender offer documents) filed with the SEC.

THE TENDER OFFER MATERIALS (INCLUDING AN OFFER TO PURCHASE, A RELATED LETTER OF TRANSMITTAL AND CERTAIN OTHER TENDER OFFER DOCUMENTS) AND THE SOLICITATION/RECOMMENDATION STATEMENT WILL CONTAIN IMPORTANT INFORMATION. HOLDERS OF SHARES OF HILLEVAX’S COMMON STOCK ARE URGED TO READ THESE DOCUMENTS CAREFULLY WHEN THEY BECOME AVAILABLE (AS EACH MAY BE AMENDED OR SUPPLEMENTED FROM TIME TO TIME) BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION THAT HOLDERS OF SHARES OF HILLEVAX’S COMMON STOCK SHOULD CONSIDER BEFORE MAKING ANY DECISION REGARDING TENDERING THEIR SHARES.

The Offer to Purchase, the related Letter of Transmittal and certain other tender offer documents, as well as the Solicitation/Recommendation Statement, will be made available to all holders of shares of HilleVax’s common stock at no expense to them. The tender offer materials and the Solicitation/Recommendation Statement will be made available for free at the SEC’s website at www.sec.gov or by accessing the Investor Relations section of Parent’s website at https://investors.xoma.com/.

EXHIBIT INDEX.

Index No.
99.1		Press Release issued by XOMA Royalty Corporation on August  4, 2025.

FAQ

What did XOMA Royalty Corporation announce about HLVX?

It filed a Schedule TO-C indicating an upcoming tender offer to acquire all outstanding HilleVax shares.

Has the HilleVax (HLVX) tender offer started?

No. The filing is pre-commencement; the actual offer will begin after Schedule TO documents are filed.

Is the purchase price for HLVX disclosed?

No price, premium or CVR value is included in this preliminary communication.

When was the merger agreement signed?

The Agreement and Plan of Merger was executed on August 4, 2025.

Where can shareholders find future tender documents?

Once available, they will be posted free on www.sec.gov and in XOMA’s investor relations section.