Once-weekly IcoSema versus once-daily insulin glargine U100 in type 2 diabetes management (COMBINE 4): an open-label, multicentre, treat-to-target, randomised, phase 3b trial.
BACKGROUND: Stepwise treatment intensification is recommended for managing type 2 diabetes, including insulin initiation when non-insulin glucose-lowering medications are insufficient. Guidelines recommend combining a GLP-1 receptor agonist with basal insulin to improve glycaemic efficacy while reducing weight gain and hypoglycaemia risk. COMBINE 4 evaluated the efficacy and safety of IcoSema, a once-weekly combination therapy of basal insulin icodec and semaglutide (a GLP-1-receptor agonist) versus insulin glargine U100 (glargine U100) in people with type 2 diabetes on oral glucose-lowering medications. METHODS: COMBINE 4 was a 40-week, randomised, open-label, treat-to-target, phase 3b trial conducted across 97 sites in nine countries. Adults (aged ≥18 years) with type 2 diabetes (HbA1c ≥8·0%) receiving oral glucose-lowering medications were randomly allocated in a 1:1 ratio without stratification to IcoSema or once-daily glargine U100. The titration target was 3·9-5·0 mmol/L (70-90 mg/dL). The primary endpoint was change in HbA1c and the secondary confirmatory endpoint was change in bodyweight, both from baseline to week 40, evaluated in all randomly allocated participants. Adverse events were recorded during weeks 0-45. This trial is registered with ClinicalTrials.gov (NCT06269107) and is complete. FINDINGS: Of 653 individuals screened between Feb 15 and Aug 6, 2024, 151 did not meet screening criteria and 17 withdrew before initiating treatment; 243 were randomised to IcoSema and 242 to glargine U100. Of the 485 randomly allocated participants, 286 (59%) were male and 199 (41%) were female, and median age was 58 years (range 26-82). For HbA1c, from baseline (9·57% for IcoSema and 9·50% for glargine U100), mean change to week 40 was greater with IcoSema versus glargine U100 (-3·32 vs -2·44 percentage points; estimated treatment difference [ETD] -0·88 percentage points [95% CI -1·12 to -0·63]), confirming superiority of IcoSema (p<0·001). From baseline to week 40, mean bodyweight decreased with IcoSema and increased with glargine U100 (-0·79 vs 3·81 kg; ETD -4·61 kg [95% CI -5·46 to -3·75]), confirming superiority of IcoSema (p<0·001). Rate of combined clinically significant (blood glucose <3·0 mmol/L [<54 mg/dL], confirmed with a blood glucose meter) or severe hypoglycaemia (severe cognitive impairment requiring external assistance for recovery) was statistically significantly lower with IcoSema versus glargine U100 (0·29 vs 0·59 episodes per person-year of exposure; estimated rate ratio 0·56 [95% CI 0·32 to 0·97]; p=0·04). Gastrointestinal disorders were the most frequently reported adverse events with IcoSema. INTERPRETATION: Once-weekly IcoSema demonstrated superior HbA1c reduction and bodyweight change, with lower rates of clinically significant or severe hypoglycaemia, versus glargine U100, suggesting that IcoSema might be an effective once-weekly treatment option for insulin-naive individuals with type 2 diabetes inadequately controlled on oral glucose-lowering medications. FUNDING: Novo Nordisk.