US-based Obsidian Therapeutics announced a definitive all-stock merger agreement with compatriot firm Galera Therapeutics (OTC: GRTX), concurrent with a USD 350 million private placement financing, to advance its engineered tumor-infiltrating lymphocyte (TIL) cell therapy pipeline in solid tumors. The transaction functions as a reverse merger, with Galera providing the public listing vehicle while Obsidian's cytoDRiVE platform and lead asset OBX-115 constitute the operational and scientific basis of the combined entity.
The transaction is structured as an all-stock deal in which both companies become wholly owned subsidiaries of a newly formed parent. Upon closing, pre-closing Obsidian stockholders are expected to hold approximately 53.2% of the combined company, PIPE investors approximately 45.0%, and pre-closing Galera stockholders approximately 1.8%, subject to adjustment based on Galera's net cash at closing. The combined company will operate under the Obsidian Therapeutics name and apply to trade on Nasdaq under the ticker symbol OBX. No upfront cash consideration between the merging parties was disclosed. Pre-closing Galera stockholders will receive one contingent value right per share, entitling them to 95% of all future milestone payments arising from Galera's October 2025 asset purchase agreement with Biossil.ai covering its dismutase mimetics portfolio, for up to ten years. The transaction has received board approval from both companies and is expected to close by Q3 2026, subject to stockholder approvals, SEC registration statement effectiveness, and customary closing conditions.
The USD 350 million PIPE, described as oversubscribed, draws participation from a syndicate that includes Balyasny Asset Management, Redmile, Novo Holdings A/S, RA Capital Management, RTW Investments, Wellington Management, and Atlas Venture, among others.
cytoDRiVE Platform and OBX-115
The scientific rationale centers on Obsidian's cytoDRiVE platform, which employs drug-responsive domains (DRDs) to achieve regulatable control of protein function within engineered cell therapies. The lead clinical asset, OBX-115, is an autologous TIL cell therapy incorporating regulatable membrane-bound IL-15 (mbIL-15). Conventional first-generation TIL therapies, including lifileucel, depend on high-dose systemic IL-2 administration to sustain T-cell persistence post-infusion, a requirement associated with dose-limiting capillary leak syndrome and inpatient hospitalization. OBX-115's mbIL-15 construct provides a cell-intrinsic, regulatable persistence signal that eliminates the need for exogenous IL-2, enabling outpatient administration with low-dose lymphodepletion. The product can be manufactured from tumor tissue obtained via minimally invasive outpatient core needle biopsy, reducing the procedural burden relative to approaches requiring surgical resection.