IntroductionWe compared the efficacy and safety of human regular insulin (HRI) versus rapid-acting insulin (RAI) in a type 2 diabetes population already using the V-Go insulin delivery device.Research design and methodsThis was a 14-week, multicenter, randomized, open-label, parallel-group, phase IV, non-inferiority study. Patients ≥21years of age, with inadequately controlled type 2 diabetes who were currently using the V-Go insulin delivery system with RAI, with glycated hemoglobin (HbA1c) ≥6.5% (≥48 mmol/L) to ≤12.5% (≤108 mmol/L) were randomized 1:1 to RAI continuation or switch to HRI. The primary outcome was estimated treatment difference (ETD) in HbA1c least-squares mean change from baseline at 14 weeks (prespecified non-inferiority hypothesis with 95% CI upper limit <0.4%). Primary analysis was by per protocol (PP); safety analysis was by intention to treat.ResultsWe randomized 136 patients to continued RAI treatment (n=67) or HRI (n=69); 113 patients were included in the PP analysis (RAI, n=54; HRI, n=59). Mean change in HbA1c from baseline to study end was −0.60±1.1% (95% CI −0.90 to –0.29); −6.6±12.0 mmol/mol (95% CI −9.8 to −3.2) with HRI treatment and −0.38±1.3% (95% CI −0.70 to –0.05); −4.2±14.2 mmol/mol (95% CI −7.7 to −0.5) with RAI treatment, with ETD of −0.22% (95% CI −0.67 to 0.22); −2.4 mmol/mol (95% CI −7.3 to 2.4), p=0.007, confirming non-inferiority of HRI to RAI. No between-group differences in changes in total daily insulin doses, number of hypoglycemic values (≤70 mg/dL (≤39 mmol/L) or body weight were observed. No severe hypoglycemic events were reported. Direct pharmacy cost savings (−US$265.85; 95% CI −US$288.60 to −US$243.11; p<0.0001) were observed with HRI treatment.ConclusionsIndividuals with type 2 diabetes requiring insulin can be treated with V-Go wearable insulin delivery device using HRI, safely and effectively, and potentially at a much lower cost compared with RAI, which can lead to improved access to insulin therapy for these individuals.Trial registration numberNCT03495908.