Vertex Pharmaceuticals on Monday reported positive three-month data for the first patient enroled in its Phase I/II trial of VX-880, the company's allogeneic stem cell-derived, pancreatic islet cell replacement therapy for type 1 diabetes. Bastiano Sanna, chief of cell and genetic therapies at Vertex, called the results "unprecedented," with the company noting this is the first instance of a patient with type 1 diabetes achieving restoration of islet cell function from such a cell therapy.
The single-arm study is being conducted in patients who have type 1 diabetes with impaired hypoglycaemic awareness and severe hypoglycaemia. Approximately 17 patients will be enrolled in the trial, with the first two treated with half the target dose, followed by dose escalation to the target dose in subsequent participants. The patient whose results Vertex revealed on Monday had been diagnosed with type 1 diabetes about 40 years ago and was dependent on exogenous insulin. The individual received a single infusion of VX-880 through a hepatic portal vein in conjunction with standard immunosuppressive therapy.
Islet cell function was evaluated using a Mixed Meal Tolerance Test (MMTT). Fasting and stimulated C-peptide levels were undetectable at the start of the study, indicating the patient was not producing endogenous insulin.
However, 90 days after VX-880 infusion, Vertex said fasting C-peptide was 280 pmol/L, reflecting restored basal insulin production, and increased after MMTT stimulation to a peak of 560 pmol/L, pointing to restored glucose-responsive insulin production. The patient experienced a 91% decrease in daily insulin requirement, needing only 2.9 daily units at the 90-day visit. The patient also saw improvements in glycaemic control, including HbA1c, which went from 8.6% at baseline to 7.2% at 90 days post-infusion.
Most side effects were considered mild-to-moderate, and there were no serious adverse reactions. The most common adverse events involved severe hypoglycaemia, which Vertex said "were non-serious, not related to VX-880 and occurred in the perioperative period."
"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," Sanna remarked. Vertex says it intends to continue the Phase I/II programme for VX-880. It is also progressing investigational new drug (IND)-enabling studies for its encapsulated islet cell programme and plans to file an IND for this program in 2022. The company obtained VX-880, formerly known as STx-02, as part of its $950-million acquisition of Semma Therapeutics in 2019.
For a closer look at today's results, see ViewPoints: Technically speaking – small win for Vertex's VX-880 in T1D.
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