Leading the way in the development of a functional cure for type 1 diabetes, Vertex Pharmaceuticals shared exciting progress from its Phase 1/2 clinical trial on the first day of the American Diabetes Association’s 84th annual Scientific Sessions.

Quick highlights on 12 current participants in the VX-880 trial:

Participants received a single infusion of VX-880. This is a transplant of healthy laboratory-grown islet cells, which include the insulin-producing beta cells which die off in type 1 diabetes.
All participants are now producing “endogenous” insulin. Their bodies are once again producing insulin.
Seven participants achieved insulin independence by the 180-day mark after receiving the VX-880 infusion. This means they no longer need daily insulin therapy via injections or pumps.
Two have reduced their need of insulin by 70 percent — and may achieve “insulin independence” in the future.
One participant needs 24 percent less daily insulin.
11 of 12 participants have experienced a significant reduction or complete elimination of the need for daily insulin therapy.

Here, we’ll take a closer look at this VX-880 and Vertex’s mission to develop a cure for type 1 diabetes.

What is VX-880?

VX-880 is Vertex’s first investigational therapy using insulin-producing islet cells that are infused directly into the participant’s hepatic portal vein — this vein transports blood from the pancreas to the liver.

We have known for decades that it is possible to transplant healthy insulin-producing cells into the body of a person with type 1 diabetes. Unfortunately, islet cell transplantation is not a practical solution for the vast majority of people with the condition. One major reason is the fact that islet cells can only be harvested from the pancreas of a deceased organ donor. 

Vertex has broken new ground by refining a technique to mass-produce new islet cells in a laboratory, using pluripotent stem cells. No longer, it seems, will islet cell transplants be limited by the number of organ donors available. In fact, last year they partnered with Lonza to build a manufacturing plant in New Hampshire dedicated entirely to producing these insulin-producing cells. (That should tell you how serious they are about bringing this to the market some day!)

The results strongly suggest that Vertex’s lab-grown cells work. A majority of study participants are now insulin independent.

If there’s a catch, it’s the fact that VX-880 requires immunosuppression therapy. Otherwise, your immune system would attack and destroy those new foreign cells. As exciting as the possibility of insulin independence is, many people in the type 1 diabetes community are understandably nervous about switching one medication regimen for another.

VX-880’s participation requirements were relatively limited for this reason: The side effects and risks that come with immunosuppression therapy must be worth it. Amongst other complications, participants in the VX-880 clinical were all experiencing frequent and severe hypoglycemic events prior to the trial.

According to this recent update, none of 12 trial participants have experienced any severe hypoglycemic events. There have also been no notable side-effects or complications from VX-880. 

You Should Also Know About VX-264

Is VX-880, if it confers insulin independence, a cure? It’s an open question. Some experts believe that type 1 diabetes can only be considered cured if the therapy does not require immunosuppressive treatment.

The VX-880 trial is the first step in testing the efficacy of these manufactured cells, but Vertex also has a plan to test a version of its treatment that does not require anti-rejection drugs.

VX-264 is Vertex’s second clinical trial focused on a functional cure for T1D. VX-264 uses the same manufactured insulin-producing cells, but without the immunosuppression therapy. Instead, VX-264 protects the cells from your immune system with a device that is surgically implanted along with the cells. It physically blocks the immune cells, while allowing insulin to flow into the blood.

VX-264 began recruiting in mid-2023 but Vertex hasn’t shared significant results yet.

VX-880’s success paves the way for VX-264 because it means the cells themselves do successfully produce insulin. The tricky part is developing an effective method of protecting them from the recipient’s immune system. 

Two Participant Deaths

Originally, there were 14 participants in the VX-880 trial. Two participants died in late 2023, which required Vertex to officially pause the study. Vertex shared further details on these deaths in this latest update.

Both participants’ deaths were deemed unrelated to the trial:

Participant death #1: “Cryptococcal meningitis infection due to complications from an elective sinus surgery (cribriform plate injury), high-dose steroids use (prohibited by protocol) in the weeks preceding and following the sinus surgery, and immunosuppressive medications.” 

Layman’s terms: A fungal infection after surgery for a voluntary facial surgery along with high-dose steroid use, which can cause severe hyperglycemia.

Participant death #2: “Progression of pre-existing neurocognitive impairment due to a severe traumatic brain-injury sustained in a motor vehicle accident caused by a severe hypoglycemic event before study enrollment.”

Layman’s terms: Progression of a brain injury from a car accident that occurred prior to the trial. The accident had been caused by a severe low blood glucose event.

With the utmost respect for these participants and their families and friends, Diabetes Daily is grateful to these two people for their contribution to this groundbreaking cure research.

Vertex is Still Recruiting More People with Type 1 Diabetes

Thanks to its success so far, Vertex has received FDA clearance to expand the trial and enroll 37 total participants.

Learn more about Vertex’s clinical trials here: VX-880 and VX-264.