Novel Once Weekly Basal Insulin Fc (BIF) Achieved Similar Glycemic Control with A Comparable Safety Profile Versus Insulin Degludec in Patients with Type 1 Diabetes (T1D)

Objective

Basal Insulin Fc (BIF; insulin efsitora alfa; LY3209590), a fusion protein combining a novel single-chain insulin variant with a human IgG Fc domain, is designed for once weekly basal insulin administration. This Phase 2 study assessed safety and efficacy of BIF versus degludec in N=265 patients with type 1 diabetes (T1D) using multiple daily injections.

Research Design and Methods

During this randomized, parallel, open-label study, patients with T1D were randomized (1:1) to receive BIF once weekly or degludec once daily over the 26-week treatment period. Both groups were titrated to fasting glucose 80-100 mg/dL. Primary endpoint was HbA1c change from baseline to Week 26 (non-inferiority margin=0.4%). Secondary endpoints included percent time in range (TIR, 70-180 mg/dL), CGM fasting glucose (FG), and rate of hypoglycemia.

Results

After 26 weeks, BIF demonstrated non-inferior HbA1c change from baseline versus degludec with a statistically significant treatment difference of 0.17% (90% CI=0.01, 0.32; p=0.07) favoring the comparator. Percent TIR was similar for BIF (56.1%) and degludec (58.9%; p=0.112) at Week 26. FG values were significantly higher for BIF (158.8 mg/dL) versus degludec (143.2 mg/dL; p=0.003). Rates of CGM-derived hypoglycemia were not statistically significantly different for BIF and degludec over 24 hours for Level 1 (p=0.960) or Level 2 (p=0.517) during the treatment period. Occurrence of serious adverse events was similar between BIF and degludec.

Conclusions

Once weekly BIF demonstrated non-inferior glycemic control to once daily degludec (treatment difference: 0.17% favoring degludec) and no difference in hypoglycemia or other safety findings in patients with T1D.