Boundless Bio and Serapha Bio amend merger agreement terms

Boundless Bio, Inc. and Serapha Bio, Inc. entered into an amendment to their merger agreement on August 28, 2026, according to a Form 8-K filed with the SEC. The original agreement, signed June 22, 2026, involves Boundless Bio, its merger subsidiary Boulder Merger Sub Corp., and Serapha, with the merger subsidiary set to combine into Serapha so that Serapha becomes a wholly owned subsidiary of Boundless Bio.¹

The amendment makes several changes to the deal terms. It clarifies certain definitions tied to the company's pre-closing financing, sets up conversion mechanics so that outstanding Serapha restricted stock unit awards become similar awards in Boundless Bio common stock adjusted by the exchange ratio, adds provisions for issuing pre-funded warrants priced at $0.00001 per share when share issuance would push a holder past ownership limits, and changes the vote standard for increasing authorized Boundless Bio shares to a majority of shares actually cast rather than a majority of all shares outstanding and entitled to vote.¹

Apart from these changes, the terms of the original merger agreement filed as an exhibit to the June 23, 2026 Form 8-K remain in place.¹

The filing notes that Boundless Bio plans to submit a Form S-4 registration statement containing a combined proxy statement and prospectus in connection with the transaction, and that stockholders will later have access to that document along with other SEC filings related to the deal. Information about Boundless Bio's directors and executive officers, who may be considered participants in the proxy solicitation, appears in the company's definitive proxy statement filed with the SEC on April 28, 2026.¹ The filing was signed by Jessica Oien, President, Chief Legal Officer and Corporate Secretary of Boundless Bio.¹