Obsidian completes Galera reverse merger and USD 350m PIPE raise

Cambridge, Massachusetts-based Obsidian Therapeutics (Nasdaq: OBX) completed its reverse merger with Galera Therapeutics on August 3, 2026, simultaneously closing an oversubscribed USD 350 million private investment in public equity (PIPE) to fund clinical advancement of its engineered tumor-infiltrating lymphocyte (TIL) cell therapy pipeline. Shares of the combined company, which retains the Obsidian name, began trading on Nasdaq under the ticker OBX on August 4, 2026.

The transaction was structured as an all-stock merger in which both companies became wholly owned subsidiaries of a newly formed parent. At closing, former Obsidian stockholders held approximately 51.6% of the combined company, PIPE investors approximately 47.2%, and former Galera stockholders approximately 1.2%. Galera stockholders of record as of July 31, 2026 received a non-transferable contingent value right (CVR) entitling them to 95% of future milestone payments arising from Galera's October 2025 asset sale of its dismutase mimetics portfolio to Biossil.ai, for up to ten years. The USD 350 million PIPE, described by the company as oversubscribed, drew participation from Balyasny Asset Management, Redmile, Novo Holdings A/S, RA Capital Management, RTW Investments, Wellington Management, and Atlas Venture, among others. The combined cash position is expected to fund operations into the second half of 2028.

The scientific rationale centers on OBX-115 (cytoTIL15), an autologous TIL cell therapy engineered with pharmacologically regulatable membrane-bound IL-15 (mbIL15) via Obsidian's cytoDRiVE platform, which uses drug-responsive domains to control transgene protein function. Unlike lifileucel (Iovance Biotherapeutics), the only currently US FDA-approved TIL therapy, OBX-115 eliminates the need for exogenous high-dose interleukin-2 by providing a cell-intrinsic persistence signal through mbIL15, enabling outpatient-compatible low-dose lymphodepletion and tumor tissue procurement via minimally invasive core needle biopsy. Phase 2 data presented at the 2026 American Society of Clinical Oncology Annual Meeting from the Agni-01 multicenter study (NCT06060613) reported a 67% objective response rate at the recommended Phase II dose in 15 patients with immune checkpoint inhibitor-resistant advanced melanoma, with no dose-limiting toxicities, no immune effector cell-associated neurotoxicity syndrome (ICANS), and no intensive care unit transfers. OBX-115 holds US FDA Fast Track and Regenerative Medicine Advanced Therapy (RMAT) designations for the melanoma indication. The company said it plans to pursue a single-arm accelerated approval pathway and expects to begin enrolling patients in the registration-enabling cohort in mid-2026. Phase I data in non-small cell lung cancer (NSCLC) are expected in the first half of 2027, with melanoma registration-enabling topline data targeted by year-end 2027.

The Obsidian/Galera structure is one of several comparable reverse mergers executed in 2026 by clinical-stage biotechs using listed shells to access public capital. Caldera merged with Synlogic to fund Phase II trials of a TL1A × IL-23p19 bispecific antibody for inflammatory bowel disease alongside a USD 278 million PIPE, while Scancell merged with Neuphoria to fund a USD 89 million Phase III melanoma trial — the latter directly parallel in both structure and therapeutic focus. For Obsidian, the reverse merger provides a public currency and balance sheet to prosecute two near-term data readouts without dilutive follow-on offerings, while the RMAT designation and Phase II efficacy signal in a high-unmet-need melanoma population support the accelerated approval strategy the company has indicated it intends to pursue.

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