Sangamo is on course to run out of money within months and has now lost access to up to $220 million in milestone payments from Pfizer.
Pfizer has terminated its hemophilia A gene therapy partnership with Sangamo Therapeutics, the companies revealed on Monday, sending the biotech’s stock down 56% on the last day of 2024.
The drug candidate, giroctocogene fitelparvovec, is designed to enable adults with moderately severe to severe hemophilia A to produce Factor VIII. A Phase III trial of the therapy hit its primary endpoint last year, linking the gene therapy to a significant reduction in the annualized bleeding rate across at least 15 months of follow-up. The companies shared more data from the trial in December.
Pfizer indicated to Sangamo in November that it was discussing the data with regulatory authorities, the biotech said. Sangamo expected Pfizer to file for approval in the U.S. and European Union in early 2025. Instead, Pfizer axed plans to seek approval and terminated the partnership.
The change of plans comes amid evidence that the market for first-generation hemophilia A gene therapies may be smaller than expected. BioMarin Pharmaceutical won FDA approval for a hemophilia A gene therapy in June 2023, only for a slow launch to prompt the biotech to narrow its focus to three markets. Sales of that product, Roctavian, totaled $16 million across the first nine months of 2024.
People with hemophilia A already have access to drugs such as Roche’s once-weekly treatment Hemlibra, and have so far largely stayed on existing products rather than try Roctavian. Studies have raised doubts about the durability of the effects of Roctavian and giroctocogene fitelparvovec, which are designed to be one-time treatments.
Sangamo will regain full rights to its program when Pfizer’s termination takes effect in April. The biotech said it plans to “explore all options” for bringing the gene therapy to market, including looking for a new partner for the program.
Shares in Sangamo fell 56% to $1.02 in the aftermath of the news. The response reflects the loss of a potentially significant source of income: Pfizer paid $70 million upfront to license the candidate and gave Sangamo a further $55 million in milestones as the program progressed.
Bigger paydays were on the horizon. On an earnings call in November, Sangamo CEO Sandy Macrae said Pfizer could pay up to $220 million in regulatory and commercial milestones “over the next two years.”
The loss of that potential income adds to Sangamo’s financial challenges. Sangamo said in November that it had enough money to fund operations into the first quarter of 2025. The biotech made the cash runway forecast before securing $20 million upfront from Astellas in return for rights to gene therapy delivery technology.
