Sangamo to regain rights to hemophilia A gene therapy
Pfizer declines to seek regulatory submissions for giroctocogene fitelparvovec
Sangamo Therapeutics will regain full rights to develop and market giroctocogene fitelparvovec, a gene therapy candidate for adults with moderately severe to severe hemophilia A, after Pfizer decided to end its involvement in the program.
Pfizer’s decision not to advance into regulatory submissions came despite positive results from AFFINE (NCT04370054), an open-label Phase 3 clinical trial where about two-thirds of the patients remained free of bleeding episodes over nearly three years after a single infusion.
Sangamo plans to explore continuing the program, including finding a new partner to help bring the gene therapy to market, while Pfizer transitions the program back to Sangamo. Pfizer’s collaboration and license agreement is set to end by April 21.
“Giroctocogene fitelparvovec has demonstrated the potential to be a life-changing gene therapy treatment for hemophilia A patients and, following positive results from the Phase 3 AFFINE trial, we believe it is well positioned for regulatory submissions and potential commercialization,” Sandy Macrae, PhD, Sangamo’s CEO, said in a company press release.
Pfizer was expected to submit a biologics license application (BLA) to the U.S. Food and Drug Administration and a marketing authorization application (MAA) to European regulatory authorities for giroctocogene fitelparvovec’s approval this year.
“While we were surprised and extremely disappointed by Pfizer’s decision to end our collaboration so close to the anticipated BLA and MAA submissions, especially given the compelling pivotal clinical trial data, we appreciate their collaboration in leading a robust and successful clinical development program and for advancing the asset to this important stage,” Macrae said.
How does giroctocogene fitelparvovec work in hemophilia A?
Hemophilia A is caused by mutations in the F8 gene, which provides instructions for producing factor VIII (FVIII), a protein needed for blood to clot. Without functional FVIII, blood cannot clot properly, leading to prolonged bleeding episodes.
Giroctocogene fitelparvovec delivers a working version of F8 to the liver using a viral vector that’s safe for humans. Given as a single infusion into a vein, giroctocogene fitelparvovec enables liver cells to produce FVIII, which should prevent bleeding episodes, offering a potential long-term solution for hemophilia A.
AFFINE is testing how safe a single infusion of giroctocogene fitelparvovec is and how well it works to reduce bleeding episodes in 75 adult men with hemophilia A who completed a minimum of six months of routine FVIII replacement therapy in a prior lead-in study (NCT03587116).
Results showed giroctocogene fitelparvovec significantly reduced the mean total annualized bleeding rate, a measure of the total number of bleeding episodes occurring in a year, with values dropping from 4.73 in the lead-in study to 1.24 after gene therapy. The therapy was also generally well tolerated.
“We are committed to exploring the optimal path forward for this important treatment, including seeking the right partner with the focus and understanding of the genomic medicine commercial environment to bring this medicine to patients,” Macrae said.
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