Vertex Discontinues Islet Cell-Device Combo for Type 1 Diabetes, Focuses on Alternative Treatment

Vertex Pharmaceuticals has announced the discontinuation of its islet cell-device combination therapy, VX-264, for type 1 diabetes following disappointing results in a phase 1/2 trial. The company will now concentrate its efforts on zimislecel, another islet cell treatment currently in phase 3 testing.

VX-264 Falls Short in Clinical Trial

Vertex's VX-264, a therapy involving surgically implanted insulin-producing cells, failed to demonstrate sufficient improvement in insulin production biomarkers during a 90-day analysis. The treatment, while safe and well-tolerated, did not achieve the necessary levels of C-peptide increase to deliver meaningful benefits to patients with type 1 diabetes.

Dr. Carmen Bozic, Vertex's Chief Medical Officer, acknowledged the setback, stating, "Today's data show that more work needs to be done to advance the 'cells plus device' program, and we are committed to doing so." The company plans to conduct further analyses, including examination of explanted devices, to better understand the results.

Zimislecel Advances to Late-Stage Development

Despite the setback with VX-264, Vertex remains optimistic about its other islet cell therapy, zimislecel. This allogeneic human stem cell-derived treatment is currently progressing through a phase 3 study, with dosing expected to complete in the first half of 2025. Unlike VX-264, zimislecel is administered alongside immunosuppressants to enhance cell grafting.

Dr. Bozic expressed enthusiasm for zimislecel's progress, noting, "We are very pleased with the rapid progress of our zimislecel program, which is on track to complete enrollment and dosing in the phase 3 study this summer, positioning us for global regulatory submissions in 2026."

Industry Implications and Competition

The discontinuation of VX-264 has implications beyond Vertex. William Blair analysts described the development as "disappointing," as it would have significantly expanded Vertex's reach in the type 1 diabetes market. The analysts raised questions about the nature of VX-264's encapsulation and the possibility of tissue rejection responses in the absence of pharmaceutical immunosuppression.

Meanwhile, competition in the field remains active. Sana Biotechnology has reported early success with its own allogeneic cell therapy for type 1 diabetes, demonstrating consistent C-peptide levels in a single patient after four weeks of treatment.

As Vertex refocuses its efforts on zimislecel, the company is investing in expanding its manufacturing and commercial capabilities to ensure launch readiness. The outcome of the ongoing phase 3 trial and subsequent regulatory submissions will be crucial in determining Vertex's position in the evolving landscape of type 1 diabetes treatment.