PTC Therapeutics completes ST-920 Fabry gene therapy buy from Sangamo

PTC Therapeutics, Inc. said on September 21, 2026 that it completed its previously announced agreement with Sangamo Therapeutics, Inc. to acquire ST-920, a BLA-stage one-time AAV gene therapy for Fabry disease.

In a Form 8-K filed the same day (AccNo 0001070081-26-000023), PTC furnished a press release under Item 7.01 and stated under Item 8.01 that it had completed the Acquisition. The close release does not restate purchase-price terms; those economics come from PTC’s August 12–13 announcement that it was the winning bidder in a competitive bankruptcy auction for the program.

Previously disclosed economics

According to Form 8-K AccNo 0001104659-26-095424 and its Exhibit 99.1 dated August 12, 2026, the auction terms included a $111 million upfront payment and up to $100 million in contingent milestone payments tied to certain regulatory approvals. The same prior 8-K describes that $100 million as comprising $80 million upon receiving accelerated approval and $20 million upon receiving traditional approval. This brief treats those figures as the last filed economics and notes that the September 21 close package does not reconfirm or amend them.

BLA path and designations

Item 8.01 of the close 8-K states that a rolling biologics license application to the U.S. FDA for accelerated approval of ST-920 is expected to be completed in the fourth quarter of 2026, based on Phase 1/2 STAAR study evidence of clinical effect on renal function and a safety and tolerability profile over 52 weeks. PTC also says it expects to pursue regulatory approval of ST-920 outside the United States. Exhibit 99.1 to the close filing states that FDA has granted Orphan Drug, Fast Track, and RMAT designations to isaralgagene civaparvovec (ST-920), and cites EMA Orphan Medicinal Product designation and PRIME eligibility plus UK MHRA Innovative Licensing and Access Pathway status.

Disease context from prior release

The August 12 Exhibit 99.1 estimates about 11,000 people living with Fabry disease in the United States and framed a potential commercial launch in 2027; those statements remain attributed to that prior release and are not restated in the close 8-K body.