Sangamo Updates Phase 1/2 STAAR Study: Fabry Disease Data Shows Sustained Benefits, Kidney Function Improvement, and Safety

Sangamo Therapeutics, a prominent company in the field of genomic medicine, recently shared new insights from its ongoing Phase 1/2 clinical study, known as the STAAR study. This study is focused on evaluating isaralgagene civaparvovec (ST-920), a pioneering gene therapy aimed at treating Fabry disease—an inherited disorder resulting from deficient activity of the enzyme alpha-galactosidase A (α-Gal A). This deficiency leads to the accumulation of certain fats, causing various health issues.

The latest data shed light on the promising potential of ST-920 as a long-lasting, one-time treatment for Fabry disease. As of the latest update, the longest treated patient has maintained elevated α-Gal A activity for nearly four years. This is a significant finding, as increased activity of this enzyme is crucial for managing the disease effectively. Additionally, in a cohort of 23 patients who had been monitored for at least a year, there were notable improvements in their renal function, as indicated by a positive mean estimated glomerular filtration rate (eGFR) slope.

A major highlight of the study is that all 18 participants who had previously been undergoing enzyme replacement therapy (ERT) have been able to discontinue ERT and remain off it, thanks to the effects of ST-920. This marks a significant shift in treatment approach, offering the potential for a more efficient and less burdensome intervention for patients.

The promising outcomes from this study have paved the way for potential regulatory advancements. Sangamo anticipates that data supporting an Accelerated Approval pathway will be ready in the first half of 2025. This could lead to a Biologics License Application (BLA) submission to the U.S. Food and Drug Administration (FDA) in the second half of the year. The FDA has already agreed that the ongoing Phase 1/2 study data, specifically the 52-week eGFR slope across all patients, can serve as the primary basis for this approval process.

Moreover, Sangamo is actively pursuing discussions for a potential collaboration centered around ST-920, aiming to bring this innovative treatment to more patients globally. These updates were well-received and are set to be presented at the 21st Annual WORLD Symposium in San Diego, offering the medical community further insights into the progress being made.

The STAAR study is particularly significant given its design as an open-label, single-dose, multi-center trial investigating the efficacy and safety of ST-920. It includes patients who are currently on ERT, those who are ERT pseudo-naïve, and those who have never undergone ERT. The FDA has recognized isaralgagene civaparvovec as an Orphan Drug and has granted it Fast Track and RMAT designations, underscoring the urgency and potential of this therapeutic approach.

Fabry disease itself is a serious condition caused by mutations in the GLA gene, leading to a cascade of health issues due to the accumulation of the fat Globotriaosylceramide (Gb3) in cells. It can result in damage to vital organs and various symptoms, including heart and kidney issues, neuropathic pain, and other systemic problems.

Sangamo Therapeutics remains at the forefront of genomic medicine, leveraging its advanced technologies to develop treatments for severe neurological and genetic disorders. Their continued research and development efforts aim to offer new hope for patients who currently have limited treatment options. The progress with ST-920 represents a significant step forward in the company's mission to transform the landscape of therapeutic interventions for complex diseases like Fabry.