Roche reported positive Phase II results for CT-388, an investigational dual GLP-1/GIP agonist, achieving up to 22.5% placebo-adjusted weight loss at 48 weeks in people with obesity, with strong metabolic benefits and a favourable safety profile.
Written By: Pharmacally Medical News Desk
Roche reported positive topline findings from CT388-103, a Phase II clinical trial evaluating CT-388, its investigational once-weekly dual GLP-1/GIP receptor agonist being developed for the treatment of obesity. The company said the study demonstrated significant and clinically meaningful weight loss over 48 weeks, supporting plans to advance the programme into Phase III development.
In the trial (NCT06525935), participants receiving subcutaneous CT-388 injections titrated up to a maximum dose of 24 mg achieved a placebo-adjusted weight loss of 22.5% at week 48 under the efficacy estimand. Roche noted that weight reduction remained progressive, with no evidence of a plateau by the end of the 48-week treatment period. For the treatment-regimen estimand, placebo-adjusted weight loss reached 18.3% (p < 0.001), and a clear dose-response relationship was observed, with higher doses producing greater reductions in body weight.
Roche also highlighted that a large proportion of participants met clinically important weight-loss milestones at the 24 mg dose. At week 48, 95.7% of treated participants achieved at least 5% weight loss, 87% achieved at least 10%, 47.8% achieved at least 20%, and 26.1% achieved at least 30%, underscoring the therapy’s potential to deliver substantial weight reduction in people living with obesity.
Beyond weight outcomes, the company reported improvements in glycaemic status among participants with prediabetes at baseline. Roche said 73% of prediabetic participants treated with CT-388 at 24 mg achieved normal blood glucose levels at week 48, compared with 7.5% in the placebo group, suggesting potential benefit in delaying or preventing progression to type 2 diabetes.
CT-388 was generally well tolerated, with most gastrointestinal adverse events described as mild-to-moderate and consistent with the incretin class of medicines. Roche added that discontinuation due to adverse events remained low, occurring in 5.9% of participants in the CT-388 arms compared with 1.3% in the placebo arm. Full study results are expected to be presented at an upcoming medical congress.
Levi Garraway, M.D., Ph.D., Roche’s Chief Medical Officer and Head of Global Product Development, said the robust weight loss combined with the tolerability profile reinforces confidence in the clinical development programme as the company prepares to move into Phase III trials. Roche views CT-388 as an important component of its expanding cardiometabolic portfolio.
Since integrating CT-388 into its pipeline, Roche has designated the candidate as a fast-track asset and accelerated its development timeline. The drug is currently being studied in another Phase II trial (CT388-104) in participants with obesity or overweight and type 2 diabetes. Roche stated that its Phase III obesity programme, Enith1 and Enith2, is expected to begin this quarter, and the company is also considering CT-388 as a potential combination asset with petrelintide.
CT-388 is an investigational dual GLP-1/GIP receptor agonist designed to reduce appetite and regulate blood glucose through selective activation of both receptors involved in energy homeostasis. Roche noted that the molecule was engineered to provide potent receptor activation with minimal ß-arrestin recruitment, which may reduce receptor desensitisation and support prolonged pharmacologic activity.
Roche emphasized the growing global burden of obesity, calling it one of the greatest single risk factors for chronic disease worldwide. The company noted projections suggesting that by 2035, more than four billion people could be living with excess weight or obesity, increasing strain on healthcare systems due to associated comorbidities and reduced quality of life.
References
[Ad hoc announcement pursuant to Art. 53 LR] Roche announces positive Phase II results for its dual GLP-1/GIP receptor agonist CT-388 in people living with obesity, 27 January 2026, https://www.roche.com/media/releases/med-cor-2026-01-27
A Study of CT-388 in Participants with Obesity or Overweight With at Least One Weight-Related Comorbidity, ClinicalTrials.gov ID NCT06525935, https://clinicaltrials.gov/study/NCT06525935