Yesterday, Roche announced topline results from a phase two study of a new injectable dual agonist medicine for obesity. The drug, CT-388, delivered a reduction in body weight of 22.5% after 48 weeks at the highest dose tested (24 mg). Placebo-subtracted weight loss was 18.3% and at 48 weeks, patients taking the drug were still losing weight.

CT-388 activates both GLP-1 and GIP receptors to achieve its effect, very much like tirzepatide from Lilly does. And right now, tirzepatide is the market-leading therapy for obesity. It is, of course, tricky to compare a drug at such an early stage of development to a well-established medicine like tirzepatide. But this first look at the efficacy of CT-388 suggests that it might compare favorably.

With these good results in hand, Roche will take CT-388 into pivotal phase three studies right away.

How Will CT-388 Fit?

Roche made a $2.7 billion deal in late 2023 and announced its intent to develop “best in class” medicines for obesity. Later, the company struck a deal worth up to $5.3 billion with Zealand Pharma for an amylin agonist, petrelintide. Roche intends to study it in combination therapy with CT-388.

Yes, Roche is spending big money to claim leadership in this market. But the competition will be intense and, as a result, the market will change dramatically over the next several years.

Right now, Novo Nordisk has hopes of expanding the market with its launch of Wegovy (semaglutide) tablets. Lilly is hot on their heels, looking for an approval of orforglipron tablets as early as this spring.

The Market Will Change

And it might be that a dual agonist will be old news after a triple agonist emerges in the form of retatrutide. In short, competition will be coming from many directions and the only certainty is that better therapies are on the way. Healthcare professionals and patients will have more options than ever in the years to come for treating obesity.

So the real hope in this space is for better obesity care to reach many more people than the relative few who are receiving it now.

Click here for the press release from Roche, here, here, and here for further perspective.

Fantasy, painting by Kuzma Petrov-Vodkin / WikiArt