Vertex is ending work on one of its two clinical-stage islet cell treatments after the diabetes therapy looked unlikely to trigger sufficient levels of insulin production in a phase 1/2 trial.
The therapy in question, dubbed VX-264, involves creating insulin-producing cells and surgically implanting them into people with Type 1 diabetes. Vertex has been conducting a phase 1/2 study of this cell and device approach to measure whether it led to an increase in peak C-peptide—a biomarker of insulin production—in individuals with Type 1 diabetes during eating.
A 90-day analysis of the data showed that C-peptide increases “were not observed at levels necessary to deliver benefit,” Vertex reported in a postmarket release Friday, March 28. While the treatment was safe and well tolerated, the lack of biomarker improvement means that Vertex “will not be advancing [VX-264] further in clinical trials.”
“Vertex plans to conduct further analyses, including of explanted devices, to better understand these findings,” the company added.
It may be the end of the road for VX-264, but Vertex still has another islet cell treatment in development in the form of zimislecel. This allogeneic human stem cell-derived islet cell therapy is currently being tested in a phase 3 study that is due to complete dosing in the first half of 2025. Unlike VX-264, zimislecel is administered along with immunosuppressants to help the cells graft.
“Consistent with this progress, Vertex is investing in expanding its manufacturing and commercial capabilities to ensure launch readiness,” the company said in relation to zimislecel.
“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,” Vertex Chief Medical Officer Carmen Bozic, M.D., said in the release. “Equally, 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.”
William Blair analysts described the discontinuation of VX-264 as “disappointing given that this would have expanded Vertex’s type 1 diabetes market significantly from that being addressed from zimislecel.
“Our primary question remains on engraftment success here given the nature of VX-264 encapsulation and if a tissue rejection response was evident given lack of pharmaceutical immunosuppression provided,” the analysts added.
Sana Biotechnology has its own allogeneic cell therapy for Type 1 diabetes in the works. The donor-derived cell therapy caused excitement earlier this year when Sana showed that it had been linked to consistent levels of C-peptide in a single patient after four weeks.