A Study to Evaluate Safety, Engraftment, and Efficacy of VC-01 in Subjects With T1 Diabetes Mellitus (VC01-103)

Through histology, the potential for functional engraftment of VC-01 combination product could be assessed in Cohort 1 subjects. Explanted sentinel units from subjects were processed and stained for markers identifying the number of graft cell nuclei (i.e., signifying the cells were viable). The percentage of viable graft cells in these explanted units were then compared to the percentage of viable graft cells from the pre-clinical (i.e., animal) models. These pre-clinical models are based on animal studies performed at ViaCyte (ref: internal study report). The data in Outcome Measure Data Table represent the % of viable graft cells present in the explanted sentinels compared to what was expected based on the animal model at Weeks 4, 8, 12, and 26 (e.g., At Week 4, there was an average of 18.27% viable graft cells in the participant's explants compared to what was expected based on the animal models).

Evaluation of clinical efficacy of VC-01 combination product in Cohort 2 subjects was intended by measuring C-peptide levels during a 4-hour Mixed Meal Tolerance Test (MMTT). Blood glucose and C-peptide data were collected from subjects at timepoints 0, 30, 60, 90, 120, 180, 240 minutes after ingestion of a "meal" (i.e., BOOST drink). These C-peptide data points could be used to create the AUC calculation. If the implanted units contained mature, insulin-producing cells, stimulated C-peptide levels would be expected to increase over the time course in reaction to the meal.