Phase 2 results for Roche's obesity drug competitive, but real test may come from combination study
A weight-loss drug from Roche that aims to achieve two goals, leading to weight loss, is competitive with other drugs in its class, but from a development perspective, the candidate still lags behind rival drugs that are already commercialized or in late-stage testing. That means differentiation from the crowded field of metabolic drugs may need to come from testing weekly injections as part of combination treatments.
Roche's drug CT-388 produced a placebo-adjusted weight loss of 22.5% at the highest dose tested at 48 weeks, according to preliminary phase 2 data released on Tuesday. Weight loss did not plateau at that time point, suggesting that more weight loss may occur with longer treatment. Roche said obesity was alleviated in 54% of study participants who received the 24 mg dose, compared with 13% in the placebo group.
Roche did not disclose specific details but said the gastrointestinal side effects were classified as mild to moderate, consistent with other drugs in this class. Discontinuation due to adverse reactions occurred in 5.9% of the study drug group and 1.3% of the placebo group.
Roche said full study results will be presented at an upcoming medical meeting. A separate Phase 2 study is evaluating CT-388 in obese or overweight patients with type 2 diabetes. Roche plans to advance CT-388 into Phase 3 testing in obesity this quarter.
CT-388 is a peptide designed to activate GLP-1 and GIP receptors. These are the same targets targeted by Eli Lilly and Company's blockbuster weight loss drug Zepbound. But Roche's drug, the most advanced program from its $2.7 billion acquisition of Carmot Therapeutics in 2023, comes from a platform technology that develops drugs that provide “bias signals,” the focus of a drug's desired pathway. In the case of CT-388, the biased signal of this once-weekly injectable drug is expected to prolong its pharmacological activity.
Roche expanded its metabolic drug pipeline again last year, spending $1.65 billion to begin a collaboration on Zealand Pharma's petrelintide. This once-weekly injectable peptide drug is designed to activate amylin receptors to promote feelings of fullness. Targeting amylin is also expected to provide better tolerability and muscle protection. When the deal was announced, Roche expressed interest in testing petrelintide in combination with CT-388. Other companies developing drugs targeting the amylin receptor include AbbVie and Novo Nordisk.
William Blair analyst Andy Hsieh said in a research note that the limited data released by Roche makes it difficult to draw solid conclusions about how CT-388 compares to Eli Lilly's Zepbound or Kailera Therapeutics and Viking Therapeutics' late-stage dual GLP-1/GIP agonists. He said the company was encouraged by the low discontinuation rates throughout the study, but was most interested in the discontinuation rate in the high-dose 24 mg arm. Further differentiation may come from testing the drug in combination with petrelintide.
“We believe this combination could provide greater potency and potentially help individuals with higher body mass index achieve normal weight,” Hsieh said. “We believe this approach could allow this therapy to stand out as it enters the increasingly crowded and competitive obesity field.”
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