Philadelphia-based Passage Bio (Nasdaq: PASG) and Watertown, Massachusetts-based Remix Therapeutics have announced a definitive all-stock merger agreement that will give the private RNA-processing company a Nasdaq listing, with the combined entity operating under the Remix name and expected to trade under the ticker RMTX. The transaction is structured as a reverse merger in which Passage Bio serves as the public listing vehicle while Remix's pipeline and leadership constitute the operational core of the successor company.
Under the merger terms, pre-merger Passage Bio shareholders will hold approximately 7% of the combined company at closing, with pre-merger Remix stockholders retaining approximately 93%. Passage Bio shareholders of record at the closing date will receive a contingent value right (CVR) entitling them to a pro rata share of any net proceeds from milestones associated with Passage Bio's out-licensed pediatric gene therapy assets. The transaction has received unanimous board approval from both companies and is expected to close in Q4 2026, subject to stockholder approvals and SEC registration statement effectiveness.
Remix simultaneously secured an oversubscribed USD 100 million PIPE led by Decheng Capital, providing cash runway into 2028.
The central asset driving the transaction is REM-422, an orally available small molecule mRNA degrader targeting MYB, a transcription factor historically considered undruggable that is implicated across multiple cancers. REM-422 works by facilitating the incorporation of a poison exon into the MYB mRNA transcript, triggering nonsense-mediated decay and suppressing MYB protein expression — a mechanism that acts upstream of protein production rather than inhibiting the protein directly. The compound holds US FDA Orphan Drug Designation for both adenoid cystic carcinoma (ACC) and acute myeloid leukemia (AML), and Fast Track Designation for ACC. Phase I/2 data presented at the 2026 ASCO Annual Meeting reported a 43% overall response rate at the recommended Phase II dose in biomarker-positive ACC patients, a 100% disease control rate, and durable responses exceeding one year with a favorable safety profile. ACC has no approved systemic therapies. REM-422 is also being evaluated in AML and high-risk myelodysplastic syndrome (HR-MDS). The combined company's 2027 clinical priorities include registrational Phase II data in ACC and Phase I data in AML or HR-MDS.
The Remix REMaster platform, which uses data science, biomolecular sciences, and chemistry to identify orally administered RNA processing modulators, has previously attracted validation from Roche through a collaboration and license agreement announced in January 2024 worth up to USD 1 billion in milestones, with Remix receiving a USD 30 million upfront payment. That partnership demonstrated third-party confidence in the platform's breadth beyond the oncology programs now central to the merger.