Yesterday, Vertex Pharmaceuticals shared updates from its active human trial of a stem-cell solution for T1D. This trial was all over the news last fall when the company published early results from a single patient who demonstrated a dramatic reduction in insulin use 90 days after receiving the treatment.
The product being tested, referred to as VX-880, is a line of insulin-producing cells derived and replicated from stem cells. In this trial, people with T1D receive an infusion of VX-880 cells alongside full-body immunosuppression. Later iterations are expected to include a solution for cell protection that will eliminate the need for immunosuppression.
There are two key breaking news items that the company shared yesterday:
Results from Patient #2: Not as Spectacular as the First
Vertex shared that the second patient being treated with VX-880, 150 days after receiving the treatment, has experienced a 30% reduction in external insulin and posted a 7.1% HbA1C. These stand in comparison to the first patient who, at day 90, was largely insulin-independent and, more than 270 days in, remains off insulin with a 5.4% HbA1C.
The primary purpose of the trial for these first two patients was to determine dosing tolerance and overall safety. As a result, both patients were given only "half" the intended dose. Neither patient registered any serious safety issues.
While the results from patient #2 are clearly not as strong as the first patient, any conclusion at this point would be premature, as so few patients have received the treatment. While a 30% reduction in insulin needs is quite different from insulin independence, it is still a notable and meaningful reduction, particularly from a half dose. More testing is needed, and the sooner the better.
FDA Puts a "Stop" on the Trial: Reasons Unclear
Vertex also shared that it dosed a third VX-880 trial participant with a FULL dose, rather than the half dose that was used on patients #1 and #2. The company stated that an independent panel of data monitors concluded that the results from the first two patients were sufficient to move to full dose. The FDA did not agree with this decision.
Yesterday the FDA issued a 'stop' on the trial, preventing the company from moving forward, at this time, with testing a fourth patient. The FDA demanded that the company suspend the clinical trial “due to a determination that there is insufficient information to support dose escalation with the product.”
The FDA has 30 days to provide the company with a written explanation for the suspension and to lay out what Vertex must do to get the trial back on track. A spokesperson for Vertex reports that the company is “committed to working collaboratively and expeditiously with the Agency to understand and address their questions and resume the trial in the U.S. as soon as possible.”
We are monitoring the development of this product closely and will keep you posted as updates become available.