Galera Therapeutics (GRTX) to file Form S-4 for proposed Obsidian merger

Rhea-AI Filing Summary

Galera Therapeutics, Inc. disclosed a proposed business combination with Obsidian Therapeutics and stated the parties and a newly-formed company will file a registration statement on Form S-4 that will include a proxy statement/information statement and prospectus relating to the proposed transaction.

The communication warns that the Prospectus and other SEC filings will contain important information, notes that Galera and Obsidian executives may be participants in the solicitation, and cautions that forward-looking statements about the merger, planned clinical activities, milestone payments and a concurrent private placement financing are subject to risks described in Galera’s annual report.

Insights

M&A Counsel

Filing signals a planned merger to be implemented via an S-4 merger proxy/prospectus.

The parties state they will file a Form S-4 registering the transaction and providing the combined company prospectus; that is the standard SEC path for business combinations effected by stock issuance or share exchange.

Key legal dependencies include the effectiveness of the registration statement and any required stockholder votes; timing and final terms are not specified in the excerpt, so the transaction remains conditional on future filings and approvals.

Corporate Finance Analyst

Communication outlines process and disclosures, not transaction economics.

The post confirms a concurrent private placement financing and mentions expected uses like cash runway and milestone payments in forward-looking language, but provides no financial metrics or deal consideration in the excerpt.

Investors should expect material terms, financing size, and pro forma capitalization to appear in the forthcoming Prospectus and related SEC filings.

Key Figures

Form S-4 filing: Form S-4 LinkedIn post date: April 14, 2026 Galera 10-K filing: Form 10-K for year ended December 31, 2025 +1 more

4 metrics

Form S-4 filing Form S-4 Registration statement to include proxy statement and prospectus

LinkedIn post date April 14, 2026 Date communication was posted and the filing referenced

Galera 10-K filing Form 10-K for year ended December 31, 2025 Filed March 19, 2026; referenced for director and officer information

Galera proxy statement Proxy statement filed April 10, 2026 Referenced as a source of director and officer information

Key Terms

Form S-4, proxy statement, prospectus, concurrent private placement financing, +1 more

5 terms

Form S-4 regulatory

"will file a registration statement on Form S-4 that will include a proxy"

A Form S-4 is a legal document that companies file with the government to announce and explain a major business move, such as a merger or acquisition. It provides detailed information to help investors understand how the deal might affect the company's value and future prospects, similar to a detailed blueprint that clarifies the impact of a significant change.

proxy statement regulatory

"will include a proxy statement or information statement and prospectus"

A proxy statement is a document companies send to shareholders ahead of a meeting that lays out the items up for a vote—like who will sit on the board, executive pay, and major corporate decisions—and provides background so shareholders can decide how to cast their votes or appoint someone to vote for them. Think of it as an agenda plus a ballot and briefing notes, important because the outcomes can change control, strategy, and value.

prospectus financial

"the newly-formed company will file a registration statement on Form S-4"

A prospectus is a detailed document that explains a company's plans for offering new shares or investments to the public. It’s important because it provides potential investors with key information about the company’s business, risks, and how they might make money, helping them decide whether to invest. Think of it as a guidebook for understanding what you're buying into.

concurrent private placement financing financial

"completion of the concurrent private placement financing"

forward-looking statements regulatory

"This press release contains forward-looking statements within the meaning"

Forward-looking statements are predictions or plans that companies share about what they expect to happen in the future, like estimating sales or profits. They matter because they help investors understand a company's outlook, but since they are based on guesses and assumptions, they can sometimes be wrong.

Filed by Galera Therapeutics, Inc.

pursuant to Rule 425 under the Securities Act of 1933

and deemed filed pursuant to Rule 14a-12

under the Securities Exchange Act of 1934

Subject Company: Galera Therapeutics, Inc.

Filer’s SEC File No.: 001-39114

Date: April 14, 2026

The following social media post was posted by Obsidian Therapeutics, Inc. (“Obsidian”) on LinkedIn on April 14, 2026.

Additional Information and Where to Find It

In connection with the proposed transactions between Obsidian and Galera Therapeutics, Inc. (“Galera”), Galera and the newly-formed company will file relevant materials with the SEC. The newly-formed company will file a registration statement on Form S-4 that will include a proxy statement or information statement and prospectus relating to the proposed transaction, which will constitute a proxy statement or information statement of Galera and a prospectus of the newly-formed company (the “Prospectus”). Galera and the newly-formed company may also file other documents with the SEC regarding the proposed transaction. This document is not a substitute for the Prospectus or any other document which Galera or the newly-formed company may file with the SEC or send to stockholders of Galera or Obsidian in connection with the proposed transaction. The Prospectus will be mailed to stockholders of Galera. INVESTORS AND SECURITYHOLDERS OF GALERA ARE URGED TO READ THE REGISTRATION STATEMENT AND THE PROSPECTUS AND ALL OTHER DOCUMENTS FILED OR THAT WILL BE FILED WITH THE SEC CAREFULLY AND IN THEIR ENTIRETY BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION ABOUT GALERA, OBSIDIAN AND THE PROPOSED TRANSACTION. Investors and security holders will be able to obtain free copies of the registration statement and the Prospectus (when available) and other documents filed with the SEC by Galera or the newly-formed company through the website maintained by the SEC at www.sec.gov. Copies of the documents filed with the SEC by Galera will be available free of charge on Galera’s website at www.Galeratx.com.

No Offer or Solicitation

This communication is for informational purposes only and not intended to and does not constitute an offer to subscribe for, buy or sell, or the solicitation of an offer to subscribe for, buy or sell, or an invitation to subscribe for, buy or sell, any securities of Galera, Obsidian or the newly-formed company, or the solicitation of any vote or approval in any jurisdiction pursuant to or in connection with the proposed transaction or otherwise, nor shall there be any sale, issuance or transfer of securities in any jurisdiction in contravention of applicable law. No offer of securities shall be made except by means of a prospectus meeting the requirements of Section 10 of the Securities Act of 1933, as amended, and otherwise in accordance with applicable law.

Participants in the Solicitation

This communication is not a solicitation of a proxy from any security holder of Galera or Obsidian. However, Galera and Obsidian and each of their respective directors and executive officers may be considered participants in the solicitation of proxies in connection with the proposed transaction. Information about the directors and executive officers of Galera may be found in its Annual Report on Form 10-K for the year ended December 31, 2025, which was filed with the SEC on March 19, 2026 and its proxy statement for its 2026 annual meeting of stockholders, which was filed with the SEC on April 10, 2026. Other information regarding the participants in the proxy solicitations and a description of their direct and indirect interests, by security holdings or otherwise, will be contained in Prospectus and other relevant materials to be filed with the SEC when they become available.

Forward-Looking Statements

This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Such statements include, but are not limited to, statements concerning future clinical development activities, potential milestone payments, the merger transaction and completion of the concurrent private placement financing, the expected effects, perceived benefits or opportunities and related timing with respect thereto; expectations regarding or plans for the combined company’s pipeline, and the expectations regarding the use of proceeds from the concurrent private placement financing and cash runway expectations therefrom.

These forward-looking statements relate to Galera, Obsidian and the newly-formed company (together, “us” or “we”), our business prospects and our results of operations and are subject to certain risks and uncertainties posed by many factors and events that could cause our actual business, prospects and results of operations to differ materially from those anticipated by such forward-looking statements. Factors that could cause or contribute to such differences include, but are not limited to, those described under the heading “Risk Factors” included in Galera’s Annual Report on Form 10-K for the year ended December 31, 2025. Readers are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date of this release. In some cases, you can identify forward-looking statements by the following words: “anticipate,” “believe,” “continue,” “could,” “estimate,” “expect,” “intend,” “aim,” “may,” “ongoing,” “plan,” “potential,” “predict,” “project,” “should,” “will,” “would” or the negative of these terms or other comparable terminology, although not all forward-looking statements contain these words. We undertake no obligation to revise any forward-looking statements in order to reflect events or circumstances that might subsequently arise, except as required by applicable law.

These forward-looking statements are based upon our current expectations and involve assumptions that may never materialize or may prove to be incorrect. Actual results and the timing of events could differ materially from those anticipated in such forward-looking statements as a result of various risks and uncertainties, including, without limitation:

• Statements about the synergies or benefits of the proposed transaction, including future financial and operating results, plans, objectives, expectations and intentions;

• The anticipated timing of closing of the proposed transaction and the private placement financing;

• Risks related to the combined company’s ability to correctly estimate its operating and other expenses and its cash runway;

• The ability to retain key personnel;

• Negative effects of the announcement or consummation of the proposed transaction on the market price of our capital stock and our operating results;

• Risks relating to the value of shares of the newly-formed company to be issued in the proposed transaction;

• Risks related to the newly-formed company’s ability to be listed on Nasdaq;

• Risks related to the ability to obtain approval of the Galera stockholders;

• Changes in capital resource requirements;

• Risks related to our inability to obtain sufficient additional capital to continue to advance our product candidates;

• Our and our collaborators’ ability to execute clinical programs for our product candidates;

• Results of clinical trials with our product candidates; and

• Our ability to obtain and maintain intellectual property rights and regulatory exclusivities.

FAQ

What did Galera Therapeutics (GRTX) disclose about the proposed merger with Obsidian?

Galera disclosed a proposed transaction and said parties will file a Form S-4 containing a proxy statement and prospectus. The filing process will provide detailed terms, governance and shareholder vote information in the Prospectus and related SEC submissions.

Will Galera shareholders receive a prospectus for the proposed transaction?

Yes. The Prospectus will be mailed to Galera stockholders when available. That Prospectus and other SEC filings will contain material information about the merger, participant interests, and voting or tender instructions for stockholders.

Does the announcement include deal economics or financing size for GRTX?

No. The excerpt mentions a concurrent private placement financing and milestone payments in forward-looking terms but provides no dollar amounts or deal consideration; those figures are expected in the forthcoming Prospectus.

Who are considered participants in the solicitation for the GRTX–Obsidian transaction?

Galera, Obsidian and each of their respective directors and executive officers may be considered participants in any proxy solicitation. The Prospectus will describe their direct and indirect interests by security holdings or otherwise.

Where can investors obtain the Form S-4 and Prospectus for Galera (GRTX)?

Investors can obtain free copies via the SEC website at www.sec.gov and Galera’s website at www.Galeratx.com once the registration statement and Prospectus are filed and become available.