In an early-stage trial, Vertex Pharmaceuticals' new stem cell-derived treatment for Type 1 diabetes showed "striking" results—and possibly cured one man of the disease. But diabetes experts urge caution, citing the need for further research and ongoing monitoring.

A clinical trial with 'unprecedented' results

Vertex Pharmaceuticals last month released the results of an early-stage clinical trial for a stem cell replacement therapy, called VX-880. It is designed to treat people with severe Type 1 diabetes, a disease that occurs when the body's immune system breaks down the pancreas's insulin-producing islet cells. The therapy does not aim to treat people with Type 2 diabetes.

According to the New York Times, VX-880 has been in development for decades by Doug Melton, a Harvard University biologist who set out to find a cure for Type 1 diabetes after his infant son and teenage daughter were diagnosed with the disease. The disease, which is lethal without insulin injections, can currently be "cure[d]" only with a transplant of the pancreas or islet cells, the Times reports—but an organ shortage makes that treatment impossible for most with the disease.

According to a Vertex press release, an ongoing trial for VX-880 will enroll approximately 17 participants and last for five years. However, early, unpublished data on the trial's first patient suggests that it may "cur[e]" the disease, the Times reports.

The patient, Brian Shelton, was the first to receive an infusion of VX-880 on June 29, when he participated in an early phase safety trial of the treatment, which called for extensive follow-up and mandated that he start with just half a dose. The treatment was derived from stem cells but, according to the Times, operated "just like the insulin-producing pancreas cells his body lacked." According to the Times, the trial's day 90-data revealed that Shelton's body is now able to automatically control his insulin and blood sugar levels.

"It's a whole new life," Shelton said. "It's like a miracle."

That said, there is so far at least one caveat to Shelton's treatment, the Times reports: As with patients who receive a pancreas transplant, Shelton must continuously take immunosuppressant drugs to prevent his body from rejecting the infused cells. However, Shelton said the drugs have not caused any side effects, adding that they pose a smaller risk than constantly monitoring his blood sugar and taking insulin as he had to do prior to receiving VX-880.

Amid praise, experts urge caution

Although industry experts celebrated the hope that a potential cure could be coming for many of the 1.5 million Americans suffering from Type 1 diabetes, many urged caution due to the early stage of the treatment's clinical trials, voicing concerns about possible unforeseen side effects and questions about how long the effect of treatment would last.

For instance, some experts have voiced concern over Shelton's immunosuppression. John Buse, a diabetes expert at the University of North Carolina, said, "We need to carefully evaluate the trade-off between the burdens of diabetes and the potential complications from immunosuppressive medications."

However, "bottom line, it is an amazing result," said Irl Hirsch, a diabetes expert at the University of Washington who was not involved in the research. "We've been looking for something like this to happen literally for decades."

Separately, Peter Butler, a diabetes expert at the University of California, Los Angeles who was not involved with the research, agreed that "[i]t is a remarkable result." He added, "To be able to reverse diabetes by giving them back the cells they are missing is comparable to the miracle when insulin was first available 100 years ago."

Experts involved in the trial also expressed surprise that such positive results stemmed from only a half dose, the Times reports.

"These results from the first patient treated with VX-880 are unprecedented. What makes these results truly remarkable is that they were achieved with treatment at half the target dose," said Bastiano Sanna, EVP and chief of Cell and Genetic Therapies at Vertex. "While still early, these results support the continued progression of our VX-880 clinical studies, as well as future studies using our encapsulated islet cells, which hold the potential to be used without the need for immunosuppression."

James Markmann, Shelton's surgeon at Mass General who is working on the trial, noted that no one expected the cells to function as well as they are. "The result is so striking," Markmann said, "It's a real leap forward for the field."

What's next for VX-880?

Based on the early results, Vertex said that it "plans to continue to progress the Phase 1/2 program for VX-880," noting that "[t]here are multiple active sites in the U.S., and the Clinical Trial Application has been approved in Canada."

In addition, Vertex said it is "progressing IND-enabling studies for its encapsulated islet cell program, which would potentially eliminate the requirement for immunosuppression, and plans to file an IND for this program in 2022."

According to the Times, Vertex will not announce a price for the treatment until it is granted FDA approval. (Kolata, New York Times, 11/27; Vertex press release, 10/18)