Berlin, Jan 27, 2026, 20:02 CET
- Roche reported that its experimental obesity drug CT-388 achieved a 22.5% weight loss over placebo after 48 weeks at the highest dose
- The company aims to kick off Phase 3 trials this quarter as it steps into the competitive weight-loss arena
- Initial investor reaction was lukewarm, given that heavyweights like Novo Nordisk and Eli Lilly already dominate the field
On Tuesday, Roche revealed that its experimental obesity drug CT-388 led patients to shed up to 22.5% of their body weight in a mid-stage trial. The Swiss pharma giant plans to leverage these results to advance into pivotal testing. (Roche)
Roche is stepping up in the obesity space, aiming to carve out a new growth path in an arena largely controlled by Novo Nordisk and Eli Lilly. Experts predict this sector could balloon to about $150 billion annually by the early 2030s, attracting more major pharma players into the fray. (Reuters)
Despite solid mid-stage results, CT-388 remains years away from hitting the market, while competitors already have drugs available in pharmacies and are running major outcomes trials. Roche shares edged up roughly 0.5% early Tuesday, showing investors’ cautious stance amid a crowded landscape.
CT-388 is a once-weekly injection designed to target two hormones, GLP-1 and GIP, that regulate appetite and blood sugar by signaling fullness and enhancing glucose control. Roche described the 22.5% figure as “placebo-adjusted,” meaning it reflects results compared to a dummy injection, based on patients who remained on the drug and adhered to the regimen for 48 weeks.
Roche reported that when factoring in patients who missed doses or discontinued treatment, the placebo-adjusted weight loss reached 18.3%. The Phase 2 trial involved 469 adults classified as obese or overweight with at least one weight-related condition, excluding those with type 2 diabetes.
Roche reported that over half of the patients taking the 24 mg dose dropped their body mass index below 30, the standard threshold for obesity. In comparison, only 13% of those in the placebo group achieved this. Additionally, 73% of pre-diabetic participants had normal blood sugar levels by week 48, versus just 7.5% on placebo.
Roche reported side effects typical for this class of drugs, mostly gastrointestinal issues, with no new safety concerns emerging. Treatment was discontinued due to side effects in about 5.9% of patients taking CT-388, versus 1.3% on placebo. (STAT)
“The strong weight loss results alongside a well-tolerated safety profile boost our confidence in the clinical development programme,” said Roche Chief Medical Officer Levi Garraway. Roche also announced that the Phase 3 obesity trials, Enith1 and Enith2, are set to begin this quarter.
Roche executive Manu Chakravarthy expressed optimism that weight loss hadn’t plateaued by the study’s conclusion. “Seeing no plateau and such a steep, linear path probably indicates the potential for greater efficacy,” he said.
CT-388 falls into the same broad “dual agonist” category as Lilly’s tirzepatide, marketed as Zepbound for obesity and Mounjaro for diabetes, whereas Novo’s Wegovy targets only GLP-1. Roche acquired CT-388 via its $2.7 billion takeover of U.S. biotech Carmot Therapeutics in 2023 and is using that acquisition to try to catch up with the market frontrunners.
Roche revealed that CT-388 is also under investigation in a separate Phase 2 trial involving individuals with obesity or overweight and type 2 diabetes. The company noted CT-388 might be combined with its experimental drug petrelintide as part of efforts to expand its obesity drug portfolio.
These results come from a mid-stage trial, and the most pronounced effect appeared at the highest dose tested. Bigger Phase 3 trials are still on the horizon. Larger studies might uncover rare safety concerns, higher drop-out rates in practical settings, or a narrower advantage compared to existing products — all critical factors in a market where doctors and insurers already have several top brands to pick from.
Roche plans to unveil the complete dataset at an upcoming medical congress. Meanwhile, investors will zero in on the trial designs, keep an eye on whether weight loss maintains momentum without plateauing, and watch if tolerability remains strong as dosing increases.
