Roche obesity drug shows 22.5% weight loss as it seeks to catch up with Lilly, Novo

(Jan 27, 2026) by Reuters.

BERLIN, Jan 27 (Reuters) – Roche’s experimental obesity drug, which works in a similar way to Eli Lilly’s Zepbound, produced as much as 22.5% weight loss in a mid-stage trial, underpinning the Swiss drugmaker’s efforts to catch up with dominant rivals.

The company said on Tuesday that the Phase-II efficacy rate – adjusted for the placebo effect – reflected 48 weeks of treatment and was based on participants who fully followed the treatment regimen.

Taking into account patients who fell behind the treatment plan, the placebo-adjusted weight loss was 18.3%. The company said treatment for longer would likely yield better results.