On March 9, 2023, Vertex Pharmaceuticals received FDA clearance to begin human trials with a new stem cell therapy, VX-264. VX-264 involves surgically implanting a protective device containing insulin-producing stem cells into the body of a person with type 1 diabetes (T1D) without the need for immunosuppression. 

Here’s a closer look at VX-264 and how it works. 

How does VX-264 stem cell therapy work? 

VX-264 will use the same stem cells as Vertex’s VX-880 therapy but with a different method of protecting the cells from the immune system.  

In the VX-880 program, the stem cells were delivered via infusion into the patient’s hepatic portal vein — which carries blood through several organs, including the pancreas. 

After 270 days, the first patient to receive an infusion of insulin-producing stem cells was declared insulin independent with an HbA1c of 5.2 percent. To achieve this, the patient required immunosuppression therapy, because the immune system of a person with T1D would otherwise attack and destroy the insulin-producing stem cells. Part A of VX-880 trials also declared the therapy as safe and well-tolerated, allowing them to move forward with higher dosages. VX-880 clinical trials are ongoing. On June 26, 2023, Vertex announced that the first two recipients of VX-880 are still insulin independent nearly two years after receiving their first dose of VX-880.

Fortunately, immunosuppression was not Vertex’s only long-term plan but merely a critical component for this first approach of testing these cells in human trials. 

VX-264 introduces the next phase: using the same insulin-producing stem cells in a surgically implanted device that protects the cells from the T1D autoimmune attack. 

Where do these stem cells come from? 

A critical part of any stem cell therapy’s success is the availability of stem cells. Vertex manufactures their own proprietary stem cell therapy product — which completely eliminates the need for organ donation to acquire cells. This means Vertex can essentially produce an unlimited number of these insulin-producing cells.  

What is the protective device? 

While stem cell therapy has been attempted many times over in T1D research, the trickiest part has always been protecting the cells from being destroyed by the T1D autoimmune attack. Long-term immunosuppression isn’t ideal or practical for a wide variety of reasons.  

Overcoming this obstacle is another part of what makes Vertex’s progress particularly groundbreaking. 

The small protective device is an enhanced version of Semma Therapeutic’s original technology — Vertex acquired Semma Therapeutics in late 2019 for $950 million. The protective device is a “channel array device” that protects the cells from the immune system of a person with T1D. 

This protective technology means there is no need for immunosuppressive therapy. 

When do clinic trials start? 

Clinical trials are expected to begin in late 2023 in the United States. VX-264 has also received clearance in Canada, where Phase ½ is already underway.  

“The clinical trial is a Phase 1/2, single-arm, open-label study in patients who have T1D,” explained the press release. “This will be a sequential, multi-part clinical trial to evaluate the safety, tolerability, and efficacy of VX-264.” 

 Approximately 17 patients will be enrolled in the first phase of this global clinical trial. We anticipate receiving more details on who can participate in the coming weeks. 

“We are excited to see our second program in T1D advancing into the clinic and look forward to bringing transformative, if not curative, therapies to T1D patients who are waiting,” said Bastiano Sanna, Ph.D., Executive Vice President and Chief of Cell and Genetic Therapies at Vertex. 

Vertex is investigating several methods of successfully using their manufactured insulin-producing cells. The VX-264 program is an exciting step forward in the pursuit of a life-changing treatment for people with T1D.