Boundless Bio, Inc. (Nasdaq: BOLD) and Serapha Bio, Inc., a privately held biotechnology company developing an investigational in vivo base editing therapy for Alpha-1 Antitrypsin Deficiency (AATD), today announced that they have entered into a definitive merger agreement pursuant to which Serapha will combine with Boundless Bio in an all-stock merger. Prior to the closing, Boundless Bio expects to declare a cash dividend to pre-merger Boundless stockholders. Upon completion of the transaction, the combined company plans to operate under the name Serapha Bio, Inc. and is expected to trade on Nasdaq under the ticker symbol "AATD".

In support of the proposed merger, Serapha has secured commitments for pre-closing private investments of approximately $230 million from a syndicate of investors co-led by RA Capital Management and RTW Investments and includes participation by Janus Henderson Investors, Decheng Capital, Vivo Capital, Casdin Capital, LifeSci Venture Partners, Logos Capital, Balyasny Asset Management, and Eventide Asset Management, of which approximately $138 million has already been funded in a Series A financing. The additional $92 million in funding is expected to close substantially concurrently with the merger, subject to customary closing conditions.