Cardiometabolic outcomes of once-weekly IcoSema in adults with type 2 diabetes: systematic review and meta-analysis of the COMBINE trials

Background Patients with type 2 diabetes face a high residual risk of atherosclerotic cardiovascular disease (ASCVD) despite advances in therapy. Once-weekly IcoSema, a fixed-ratio combination of basal insulin icodec and semaglutide, offers the potential to simultaneously address glycemic control, weight, and multiple cardiometabolic risk factors with a single weekly injection. Methods We conducted a PRISMA-compliant systematic review and random-effects meta-analysis of randomized trials from the COMBINE program. Data from COMBINE 1 (active comparator: once-weekly insulin icodec) and COMBINE 3 (active comparator: basal-bolus insulin therapy) ( N = 1,970) were pooled comparing IcoSema with insulin-based intensification strategies in patients inadequately controlled on basal insulin. COMBINE 2 was excluded because its semaglutide monotherapy comparator addresses a fundamentally different clinical question (escalation from GLP-1 RA monotherapy). The primary focus was on changes in body weight, Systolic blood pressure and HbA1c; key secondary outcomes included changes in lipid profile relevant to ASCVD risk. Certainty of evidence was assessed using GRADE. Results IcoSema showed no statistically significant difference in HbA1c reduction compared with control (pooled MD -0.37%, 95% CI -0.95 to 0.21; P = 0.21; I²=98%) but shows highly significant body weight reduction (pooled MD -6.10 kg, 95% CI -7.21 to -5.00; P < 0.00001). It significantly lowered systolic blood pressure (MD -2.45 mmHg, 95% CI -3.52 to -1.38; P < 0.00001), total cholesterol (ETR 0.97, 95% CI 0.95–0.98; P = 0.0001), LDL-C (ETR 0.94, 95% CI 0.90–0.98; P = 0.005), triglycerides (ETR 0.94, 95% CI 0.91–0.97; P = 0.0006), and VLDL-C (ETR 0.94). An exploratory, hypothetical ASCVD risk modeling analysis based on these surrogate-marker changes is presented in the Supplementary Appendix and is intended as an illustration only. Conclusions Once-weekly IcoSema delivers meaningful improvements in weight, blood pressure, and atherogenic lipids, all key modifiable drivers of ASCVD in adults with type 2 diabetes. These surrogate benefits, combined with reduced injection burden and low risk of hypoglycemia, suggest potential for enhanced ASCVD prevention and improved long-term adherence. Results should be interpreted as hypothesis-generating only because only two trials met the inclusion criteria. Dedicated cardiovascular outcome trials are essential to validate these surrogate-marker benefits and to confirm whether they translate into a reduction in cardiovascular events.