Sangamo Therapeutics Plans Accelerated Approval Pathway for Fabry Disease Gene Therapy
Key Insights
Sangamo Therapeutics is pursuing accelerated approval from the FDA for its Fabry disease (search) gene therapy, potentially expediting its path to market.
The FDA might allow Sangamo to use long-term data from its existing trial as a follow-up, foregoing the need for a separate confirmatory study.
Sangamo aims to use eGFR slope at 52 weeks across all patients from its Phase 1/2 study as the surrogate endpoint for approval.
Sangamo Therapeutics is set to pursue an accelerated approval pathway from the FDA for its gene therapy targeting Fabry disease (search). This decision could significantly expedite the therapy's availability to patients.
FDA's Openness to Accelerated Approvals
The FDA has recently signaled a greater willingness to consider accelerated approvals, particularly for rare diseases and cell and gene therapies. Sangamo CEO Sandy Macrae noted that the FDA has not requested additional data beyond what has already been submitted, suggesting that longer-term data from the ongoing trial may suffice as a confirmatory measure. According to Macrae, the FDA might request the continuation of the trial to gather two-year data from all participants, but this has not been explicitly required.
Implications of No Confirmatory Trial
One potential consequence of forgoing a separate confirmatory trial is that the accelerated approval may not convert to a full approval. This could impact insurance coverage and the drug's pricing. However, Peter Marks, director of the FDA's Center for Biologics Evaluation and Research (CBER), has expressed his desire for accelerated approval to "be the norm" for gene therapies, even with biomarkers that are not yet fully qualified.
Clinical Data and Surrogate Endpoint
Sangamo intends to leverage data from its Phase 1/2 study for the accelerated approval application, utilizing the estimated glomerular filtration rate (eGFR) slope at 52 weeks across all patients as the surrogate endpoint. This dataset will include one-year data from all 32 patients in the study and two-year results from 19 patients, according to Macrae.
Company Challenges and Financial Outlook
Sangamo has faced financial headwinds, with its share price declining significantly from its 2020 peak. The company has undergone multiple restructurings and workforce reductions. However, Macrae stated that the decision to pursue accelerated approval was not driven by financial concerns. Sangamo is actively engaged in late-stage partnership discussions to secure non-dilutive funding, which the CEO believes will be bolstered by this recent development. In August, Sangamo partnered with Genentech on an epigenetic Alzheimer's therapy program, receiving $50 million upfront with potential milestone payments of $1.9 billion.