Rationale and design of the phase 3a development programme (ONWARDS 1–6 trials) investigating once-weekly insulin icodec in diabetes

Aim: To describe the phase 3a ONWARDS clinical development programme investigating insulin icodec (icodec), a once-weekly basal insulin, including the design and rationale for each of the ONWARDS 1–6 trials. Materials and Methods: Six randomized controlled trials have been initiated in adults with type 2 diabetes (T2D) (insulin-naive: ONWARDS 1, 3 and 5; previously insulin-treated: ONWARDS 2 and 4) and type 1 diabetes (T1D) (ONWARDS 6). Each trial will investigate icodec use in a unique clinical scenario, with consideration of long-term safety and varied comparator treatments (insulin glargine U100 or U300 or insulin degludec). ONWARDS 5 will incorporate real-world elements and a digital dose titration solution to guide icodec dosing. The primary objective for each of the trials is to compare the change in HbA1c from baseline to week 26 or week 52 between icodec and comparator arms. Secondary objectives include investigating other glycaemic control and safety parameters, such as fasting glucose, time in glycaemic range and hypoglycaemia. Patient-reported outcomes will assess treatment satisfaction. Conclusions: The ONWARDS 1–6 trials will evaluate the efficacy and safety of once-weekly icodec compared with currently available daily basal insulin analogues in T2D and T1D. These trials will generate comprehensive evidence of icodec use in diverse populations across the spectrum of diabetes progression and treatment experience.