This drug class could be the next GLP-1. Apitegromab, a myostatin inhibitor, just got FDA approval! Myostatin is a protein that tells your muscles to stop growing. This drug inhibits myostatin. It's why Belgian Blue cattle look like Arnold Schwarzennegger. Apitegromab targets the same system by blocking myostatin activation. In patients with spinal muscular atrophy, adding it to their existing treatment improved their ability to move. But its potential could go beyond this. In a study with 102 adults on tirzepatide, half of them also received apitegromab while the other half was given a placebo. After 24 weeks, both groups lost a similar amount of weight, but those on apitegromab lost about half as much lean tissue: 1.6kg vs. 3.5 kg (this combination is still experimental). But this myostatin inhibitor is still compelling. If we safely pair GLP-1s with a drug that can preserve muscle, and it works - it could create demand for an entirely new category of treatment.