Boundless Bio Shares Surge 90% on $230M Merger Deal Funding Through 2029
BOLD•Boundless Bio soared nearly 90% after unveiling a merger with Serapha Bio, creating a combined Nasdaq-listed company under ticker AATD with an expected Q4 2026 close. The transaction secures $230M in healthcare investor financing, funds operations into H2 2029, and includes a $44–48M shareholder dividend.
1. Merger Agreement Details
Boundless Bio agreed to merge with privately held Serapha Bio, creating a unified company named Serapha Bio that will trade on Nasdaq under ticker AATD. The deal is scheduled to close in the fourth quarter of 2026, marking the largest single-day share gain in Boundless history.
2. Financing and Cash Runway
The combined company has secured $230 million in commitments from healthcare-focused investors led by RA Capital Management and RTW Investments. This financing, along with existing cash, is projected to fund operations through the second half of 2029.
3. Ownership Structure and Dividend
Under the terms, Serapha shareholders will hold approximately 96.3% of the combined firm, while Boundless investors will own about 3.7%. Boundless Bio also plans to distribute a pre-merger cash dividend of $44 million to $48 million to its shareholders.
4. Focus on SERP-01 Development
The merged entity will concentrate on advancing SERP-01, an investigational therapy for Alpha-1 Antitrypsin Deficiency licensed from YolTech Therapeutics. Bindless had halted its cancer program BBI-940 following disappointing results, redirecting efforts to the genetic disease treatment candidate.
