The 2 patients were among 6 who have received treatment in Vertex’s trial so far and were the only 2 evaluable for the primary efficacy end point.
Two patients with type 1 diabetes (T1D) with impaired hypoglycemic awareness and severe hypoglycemic events (SHEs) who were treated with Vertex Pharmaceuticals’ VX-880, an investigational allogeneic insulin-producing islet cell therapy being evaluated in a phase 1/2 clinical trial (NCT04786262), have experienced an elimination of SHEs and shown a reduction in HbA1c that met the criteria for the study's primary efficacy end point.1
The 2 patients were among 6 who have received treatment in the trial to this point and were the only 2 evaluable for the primary efficacy end point, having reached 12 months or more of follow-up after receiving their last infusion of VX-880. One of the 2 patients had an HbA1c value of 5.3% at 21 months after the last infusion, and the other patient had an HbA1c value of 6.0% at 12 months after the last infusion. These values were 8.6% and 7.6% at baseline for each patient, respectively. Both of the patients showed elimination of SHEs between Day 90 and Month 12, were insulin independent, and demonstrated a greater than 95% time-in-range on continuous glucose monitoring. They were treated in Part A of the study, in which patients received VX-880 in 2 separate infusions that each contained half of the target dose. A third patient treated in Part A withdrew from the trial after 9 months of on-study follow-up and thus was not evaluable for the primary efficacy end point. Vertex noted that the patient’s withdrawal was not related to adverse events (AEs).
Three patients have received treatment in Part B of the study, in which patients receive the full target dose of VX-880 in a single infusion. The follow-up for these 3 patients ranges from 29 days to 90 days postinfusion. Vertex noted that endogenous insulin secretion, decreases in HbA1c values, increases in glucose time-in-range, and decreases in daily exogenous insulin use have been observed among these patients and that at equivalent follow-up points the results are consistent with those of the 2 patients who were evaluable for the primary efficacy end point in Part A.
“The reproducible efficacy across multiple patients and end points, including the level of glucose control and the elimination of SHEs, observed in this trial is highly unusual in T1D patients treated with exogenous insulin, wherein only ~25% of people with T1D meet the recommended HbA1c target of 7.0%, and is truly remarkable,” Trevor Reichman, MD, FRCSC, the surgical director of the Pancreas Transplant Program in the Department of Surgery at the University of Toronto, said in a statement.1 “The normalization of HbA1c without the need for exogenous insulin 1 year after therapy with VX-880 is historic and offers hope that the transformative therapies the T1D community has been waiting for may finally become reality.”
In terms of safety, Vertex reported that VX-880 was generally well-tolerated in all patients with no serious AEs related to the treatment observed. The company also noted that the majority of AEs that occurred in the trial were mild to moderate in severity. The most common AEs reported included dehydration, diarrhea, hypomagnesemia, and rash. It was additionally noted that in the perioperative period 1 patient experienced SHEs.
“These data represent a foundational advance in the potential treatment of T1D, bringing us 1 step closer to a potentially curative therapy for patients who are waiting,” Felicia Pagliuca, PhD, disease area executive for Type 1 Diabetes at Vertex, said in a statement.1 “These data are particularly meaningful in the context of our overall investigational T1D program, as these same VX-880 cells are the building blocks for our phase 1/2 VX-264 cells-plus-device program, as well as our research-stage hypoimmune islet cell program.”
At baseline, the 6 patients treated in the trial all had undetectable fasting C-peptide and history of recurrent SHEs; they needed an average of 34.0 units of insulin each day. In light of the results seen after treatment with VX-880 in Part A and Part B, the trial’s independent data review committee recommended that the study proceed to Part C, in which patients will be administered the full target dose of VX-880.
The clinical trial for VX-880 was previously put on hold by the FDA in May 2022.2 The agency cited “insufficient information to support dose escalation” as the reason for the hold. At the time, Carmen Bozic, MD, the executive vice president of Global Medicines Development and Medical Affairs and the chief medical officer of Vertex, expressed surprise at the FDA’s decision. The hold was lifted just over 2 months later, in July 2022.3
The announcement of the new positive data from the trial for VX-880 is the latest in a series of recent positive developments in the realm of cell therapy for T1D. Most notably, on June 29, 2023, the FDA approved CellTrans’ allogeneic pancreatic islet cell therapy donislecel under the name Lantidra, for treating adults with T1D who are unable to approach target glycated hemoglobin because of current repeated episodes of severe hypoglycemia despite intensive diabetes management and education.4 Meanwhile, on June 26, Sernova announced that 5 patients with T1D with severe hypoglycemia unawareness who were implanted with the company’s Cell Pouch System, an investigational medical device containing immune protected therapeutic cells, achieved insulin independence following islet transplant to the Cell Pouch and supplemental portal vein islet infusion.5