Published, not speculated. In the REDEFINE 1 DXA substudy, 33.1% of weight lost on CagriSema was lean soft tissue, versus 30.3% for semaglutide alone (Ravussin, ObesityWeek 2025). Regeneron’s COURAGE put semaglutide monotherapy near 34.5%; SURMOUNT-1 had tirzepatide closer to 25% (Look et al., DOM 2025).
For most patients this is adaptive. For older adults, post-menopausal women and anyone with sarcopenic obesity, it is a clinical problem. Hence the race for a muscle-preserving adjunct, a market TD Cowen sizes above 30 billion USD by 2035. Apitegromab has shown it is feasible: 54.9% lean mass retention on top of tirzepatide in EMBRAZE.
Notice where almost every one of those programs sits: the myostatin and activin axis. So the practical question before any combination goes clinical: does your candidate protect human myotubes against that specific driver, and at what concentration?
That is what our matrix answers. Same four axes as the previous post, same primary human cells, with the metabolic readouts that matter here: glucose uptake, mitochondrial network, lipid accumulation.
Full drop and rescue data for each axis is in the flashcard below !
