Vertex Pharma's cell therapy for type 1 diabetes shows potential for insulin independence
Cell therapy for type 1 diabetes enables patients to produce insulin, eliminating the need for other insulin therapy in important clinical trials. With these preliminary results, drugmakers are watching the regulation of therapies in 2026 Zimislecel.
The update comes from the Phase 1/2 part of the Phase 1/2/3 study and covers 12 patients for at least one year. Vertex said all 12 met the blood sugar levels recommended by the American Diabetes Association (ADA). Treatment of type 1 diabetes requires blood sugar monitoring and frequent or continuous administration of insulin. Vertex said 10 of the 12 patients treated with Zimislecel were free of charge from the data deadline. The latest results were presented at the ADA's annual meeting in Chicago late Friday and were published online in the New England Journal of Medicine (NEJM).
Type 1 diabetes is an autoimmune disease that can lead to the destruction of islet cells that produce insulin. In an investor speech, Vertex said that among the 3.8 million people diagnosed with type 1 diabetes in the United States and Europe, there are about 60,000 life-threatening severe blood sugar-lowering events (SHES). This is a targeted Zimislecel at the apex of the patient population.
Zimislecel (formerly known as VX-880) consists of stem cell-derived pancreatic islet cells that are used as a single infusion into the hepatic portal vein. To prevent the body from rejecting cellular therapy, Zimislecel requires long-term use of immunosuppressive drugs. These drugs introduce complication risks, such as higher sensitivity to infection.
Vertex hopes to avoid chronic immunosuppression through a different program VX-264. The treatment candidate encapsulates Zimislecel in an implanted medical device that protects the immune system of the cellular therapy. In March, VERTEX stopped VX-264 after failing to meet the efficacy target in a phase 1/2 clinical trial. But the company continues to develop “naked” Zimislecel, a cell therapy without protective medical devices.
Although avoiding immunosuppression would give a key advantage in the treatment of Cramp 1 diabetes, naked Zimislecel still has the potential to differentiate. The only FDA-approved cellular therapy for the disease is Lantidra, a biotech company's cell Trans produced by islet cells from the late donor. The limitations of Lantidra include ensuring the quality and supply of cells proposed in this way. Stem cell-derived Zimislecel offers patients the prospect of “shelf” treatment alternatives.
Zimislecel's latest results show that stem cell-derived islet cells are accepted by the patient's body and lead to the production of C peptide. The peptide is released with insulin and measures its levels in the blood, providing a method to assess insulin production. Vertex said the treatment is still well tolerated, with most adverse reactions classified as mild or moderate. The NEJM article points out that the most common serious adverse event is neutropenia, which is a lower white blood cell type called neutrophils. The incident was reported in three patients. The parapet said no serious adverse reactions related to cell therapy were reported, and the safety was consistent with the immunosuppressive regimen used in the study. The company said the deaths of two previously reported patients were not associated with Zimislecel's treatment.
In a note sent to investors on Monday, William Blair analyst Myles Minter said Zimislecel helps maintain normal blood sugar levels while reducing or eliminating the need for exogenous insulin that expresses meaningful lifestyle differences for patients. He also noted that experts say 35% to 40% of patients with type 1 diabetes fail to achieve ADA glucose control guidelines using currently available treatments, which makes Zimislecel's target addressable market significantly larger than the 60,000 patients targeted by Vertex. But cell therapy still faces obstacles.
“We believe that the requirement for immunosuppressants is the biggest headwind here, which may prevent certain patient populations, and severe adverse events involving neutropenia and acute kidney injury are noted in the NEJM publication.”
Vertex said in an investor speech that it is developing an alternative to immunosuppression that is currently under research. Meanwhile, Zimislecel's Phase 1/2/3 test is expected to recruit 50 patients. Vertex hopes to complete enrollment and administer medication this summer.
Photo: David L. Ryan/Boston Globe, via Getty Images
