Major firm halts muscle-sparing obesity drug trial over business concerns, others follow suit

Interesting piece. It stands out that neither of the two biggest players could find a way to make the compound commercially viable even after the regulator hinted it might still be approvable. In the end it looks like a straightforward business call.

Thanks for posting this. I read the article too but I’m stuck on one point. The regulator’s comment that incremental weight loss over a GLP-1 alone is now an acceptable primary endpoint seems like it should make approval easier for muscle-preservation add-ons. Wouldn’t that encourage companies to finish the trials they already started rather than stop them?

This article is over a year old. The big company may have written off its purchase of the startup, but the other firm has reported strong results and has now moved into phase-two testing.

One thing that stands out from looking into this is that it is relatively easy to get a drug to increase muscle mass on paper, but much harder to prove real gains in strength or daily function. That has been the case mainly in sarcopenia studies where the muscle increases are small. It may be different when the goal is simply limiting muscle loss during GLP-1 therapy, since preserving lean mass could help keep metabolic rate up and support lasting weight control. I find it unlikely that cutting muscle loss by a large amount would have no effect on physical performance.

I think there is a misunderstanding. They stopped only one of the studies, the one in type-two diabetes patients, but left the other development program running in the non-diabetic group. It looks like they are now prioritizing the obesity indication over diabetes.

I think there is some misunderstanding here. The regulator’s remark was that the muscle-building effects themselves were not considered meaningful enough on their own. It was the company that said weight loss by itself would be acceptable even if muscle loss is ignored. Using a SARM for muscle preservation is also not the same approach as a myostatin inhibitor.

It would be interesting to know what SARM it was, for science of course.

I've noticed that compounds aimed at myostatin could trigger major unwanted reactions, making strong caution essential before any use. Even so I'm still optimistic some large drug makers will figure things out eventually, though progress so far looks pretty uneven. Several big firms have sunk serious research funds into this area, sometimes testing alongside other weight loss compounds, but most projects have run into problems like no measurable gains in mid stage trials, uneven results across studies, or work that keeps going without solid answers yet. One version helped movement in certain genetic muscle disorders, though how that might translate elsewhere stays unclear. Other tactics that block related pathways showed limited gains in small human tests but leave the safety picture murky, with at least one effort dropped after bleeding problems appeared and another still in very early stages. Proteins that latch onto myostatin directly often fall short on results or bring their own safety concerns. This direction might end up mattering a lot down the line, but nothing has clicked fully yet.

Another major risk is that myostatin acts as a growth brake. Removing that brake might affect more than just skeletal muscle and could influence organs such as the heart, liver, kidneys or intestines.

I’m very interested in one of the compounds that appears to cut lean-mass loss when used with a GLP-1 by about half. I’m curious how it would perform with other GLP-1 variants and whether it could ever be produced elsewhere. Being a monoclonal antibody makes that unlikely, and by the time it reaches the market I will probably have reached my goal weight anyway.