US company Vertex makes pancreatic cells designed for all blood types its lead program in type 1 diabetes

US company Vertex makes pancreatic cells designed for all blood types its lead program in type 1 diabetes

In its third-quarter report on November 2, Vertex announced that it is accelerating VX-017, pancreatic islets grown from stem cells. These are clusters of cells that produce insulin. Patients are already receiving them in a phase one and phase two trial.

In type 1 diabetes, the immune system destroys the insulin-producing beta cells in the pancreas. Vertex is developing a replacement for these cells: islets are infused into the hepatic portal vein, where they produce insulin in response to glucose. The company's first such product, zimislecel, is being tested with immunosuppressants, drugs that suppress the immune system to prevent rejection of the transplanted cells. In 2025, the New England Journal of Medicine published trial results: of the 12 participants who received the full dose, 10 were no longer using insulin after a year. According to a 2025 Vertex presentation, investigators attributed most adverse events related to the trial drugs to immunosuppressants; participants experienced reduced white blood cell counts and declining kidney function.

The cells used in zimislecel come from a donor with blood type A, making them suitable for people with blood type A or AB. Type A cells carry the A marker, while people with blood types O and B have antibodies against it. Type O cells carry neither the A nor the B marker, so they are intended for people of any blood type. Vertex CEO Reshma Kewalramani describes VX-017 as a blood type O, universal-donor cell product, similar in concept to zimislecel. Vertex estimates that around 60 thousand patients in the US and Europe would be eligible for zimislecel and around 120 thousand for VX-017. These are people with type 1 diabetes who, despite treatment, have recurrent episodes of severely low blood sugar that can cause loss of consciousness.

The November report attributes the decision to the rapid progress of VX-017 and its potential to reach more patients. On the November call, Kewalramani identified the larger eligible population as the main reason, given that cell therapy programs are resource-intensive, complex and demanding to manufacture. The decision followed an earlier pause: in January, Vertex delayed completion of dosing in the zimislecel trial while it reviewed manufacturing, then resumed dosing in May. In August, when the FDA cleared VX-017 for clinical trials, Kewalramani said on an investor call:

“The upside of the pause we took in the blood type A zimislecel program is that the gap in timing between the blood type O program and zimislecel has narrowed.”

A separate goal is to eliminate the need for immunosuppressants. Vertex previously tested VX-264, which enclosed cells in a protective device. On March 28, 2025, the company discontinued its clinical development: after 90 days, C-peptide, a marker of the body's own insulin production, had not reached the required level. In its November report, Vertex lists preclinical programs that have yet to be tested in humans: new ways to protect cells from the immune system and “hypoimmune” islets whose genes are edited for this purpose, according to its website. The report states that both approaches would reduce or eliminate the need for standard immunosuppressants.

Hypoimmune cells from another company, Sana Biotechnology, have been tested in a human: a patient received a transplant of gene-edited donor islets without immunosuppressants. After 12 weeks, no immune response to the cells was detected, and C-peptide was measurable in the blood.

According to Kewalramani, the immediate goals for VX-017 are to establish proof of concept in patients and scale up manufacturing so that the program can enter pivotal trials in 2027.