Passage Bio

Passage Bio is a clinical-stage genetic medicines company developing gene therapies for central nervous system diseases, built around a research collaboration with the Gene Therapy Program at the University of Pennsylvania's Perelman School of Medicine. Its lead asset, PBFT02, is an AAV1 gene therapy delivering a functional granulin (GRN) gene for the treatment of frontotemporal dementia caused by progranulin deficiency, and is the sole program the company continues to advance after electing to wind down its earlier GM1 gangliosidosis, Krabbe disease and metachromatic leukodystrophy candidates. In June 2026 Passage Bio agreed an all-stock merger with Remix Therapeutics, a clinical-stage company developing small-molecule modulators of RNA processing; on completion the combined company will be renamed Remix Therapeutics, trade on Nasdaq as RMTX, and pursue Remix's lead mRNA degrader REM-422 in adenoid cystic carcinoma and AML/HR-MDS, with legacy Passage Bio holders retaining a minority of the combined entity. The company has flagged going-concern doubt on a declining cash balance and an accumulated deficit of roughly $720 million, and the transaction is subject to a stockholder vote including a proposed reverse stock split.