Biotech Values

[Mufaso]

Lots of differing opinions on how much muscle loss comes with weight loss and for what reason. Obviously, you will get different percentages based on what your base BMI is but then it is be affected by lots of factors like how much exercise one does while in caloric deficit and/or how much protein is consumed.

I posted on ALT claim as I believe going forward, how much muscle is lost while on a weight loss drug will become a battleground between different drugs and an important market segment. Their specific claim was "only 25.5% from lean mass, comparable to the effects historically associated with weight loss from diet and exercise programs,” Anecdotally, I believe the general consensus is that 30%-40% of the typical weight loss for an obese individual is muscle. (BTW- A big problem occurs when people yo-yo back up as the weight they put back on is disproportionately higher in fat) . An article I reference below says the muscle loss figure is one third, so take your pick as to what an "average/typical" number is.

“When we look at weight reduction from any intervention, about one-third of the weight we lose tends to be lean mass, and that can be problematic,” said Dr. Jaime Almandoz, an associate professor of internal medicine in the Division of Endocrinology at UT

But answering your question on comparable drugs to ALT's I previously posted in #msg-173034452 that supposedly Wegovy weight loss was 40% muscle and Mounjaro was 25% from this article:
https://www.nbcnews.com/health/health-news/weight-loss-drugs-muscle-loss-rcna84936

Here is some data in the article from the Wegovy trial saying 40% of the weight loss was Muscle mass.

A 2021 clinical trial that tested the weight loss effects of Wegovy found that while about 40% of the weight people lost tended to be lean mass, including muscle, at the end of 68 weeks, people who took the drug had a lower risk of heart disease and better physical function compared to a placebo group.

Here is some data from a Mounjaro trial saying the muscle loss was only 25%:

Studies showed similar results for the drug tirzepatide, which is sold under the brand name Mounjaro. In a phase 3 clinical trial, “a reduction in lean mass was reported at a similar rate as what is seen in lifestyle-based treatments for obesity,” Jessica Thompson, a spokesperson for tirzepatide-maker Eli Lilly, said in an emailed statement

A new analysis of data from the same trial found that after 72 weeks of taking the drug, about 25% of the weight participants lost was lean mass. However, the participants had an overall healthier body composition. Aronne, who worked on the trial, presented the findings this week at the European Congress on Obesity in Dublin.

Viking has yet to comment on muscle loss to my knowledge.

Disclaimers about the follies of comparing different trials aside, I would be very interested in any data anyone has that shows that semaglutide is better than tirzepatide for muscle mass retention or any other thoughts anyone has here. I suspect that all of these companies will slice the data differently to make their particular drug look better than competition..
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As a final thought, BioAge is running a trial for azelaprag, an apelin receptor (APJ) agonist, in combination with Lilly’s Zepbound (tirzepatide) and therapeutic pipeline. See #msg-173838283. Hopefully when this trial runs we will see a comparator arm on tirzepatide that will show what tirzepatide muscle loss is alone in a defined patient population.