Encapsulated stem-cell derived beta cells are found to be a potential means for glucose control in people with type 1 diabetes. The findings published in ‘Nature Biotechnology’ details a novel cell therapy developed by a U.S. biotechnology company which aims to replace the insulin-producing beta cells that people with type 1 diabetes lack. Dubbed VC-02, the small medical implant consists of devices with perforated membranes, which are loaded with pancreatic endoderm cells (PEC-01) obtained by differentiation of the CyT49 human embryonic stem cell line. The devices, approximately the size of a Band-Aid and no thicker than a credit card are implanted just beneath a patient's skin to provide a steady, long-term regulated supply of self-sustaining insulin.

      The study was conducted among 10 participants at nine centers in North America and one center in Belgium. Inclusion criteria included men and non-pregnant women, with a diagnosis of T1D for a minimum of 5 years, hypoglycemia unawareness, a stable diabetes treatment regimen, willingness to use a CGM device and being an acceptable candidate for surgical implantation. A Clarke score ≥4 confirmed patients qualifying for study participation on the basis of hypoglycemia unawareness. β cell function was measured by meal-stimulated plasma C-peptide levels at 3-month intervals, and the effect on glucose control was assessed by continuous glucose monitoring (CGM) and insulin dosing.

      Of 10 patients with undetectable baseline C-peptide, three achieved levels ≥0.1 nmol l−1 from month 6 onwards that correlated with improved CGM measures and reduced insulin dosing, indicating a glucose-controlling effect. The patient with the highest C-peptide (0.23 nmol l−1) increased CGM time-in-range from 55% to 85% at month 12; β cell mass in sentinel devices in this patient at month 6 was 4% of the initial cell mass, indicating directions for improving efficacy. In summary, these participants spent more time in an optimal blood glucose range and reduced their intake of externally administered insulin.

      This trial is a first-in-human, phase 1/2, open-label study on safety, tolerability and efficacy of VC-02 in patients with T1D and hypoglycemia unawareness.