Bimagrumab and apitegromab: the race for designer muscle

Bimagrumab and apitegromab: the race for designer muscle

The pharmaceutical industry is no longer content with making fat disappear. The next step, according to trials with bimagrumab and apitegromab, is to keep the body from losing muscle mass while dieting, or even to gain it effortlessly. Both drugs, designed to inhibit the proteins that limit muscle growth, are in phase 2 trials. If nothing goes wrong, their market arrival is estimated within five to eight years.

The combination that supercharges weight loss

Data from the BELIEVE trial, involving adults with obesity, put the combination of bimagrumab and semaglutide ahead of semaglutide alone. Across 507 patients, weight loss reached 22.1% with the high-dose combination, compared with 15.7% for semaglutide alone and 10.8% for bimagrumab on its own. The most striking figure is the composition of that loss: 92.2% of the weight shed with the combination was fat. In other words: slimming down without dismantling muscle, something aggressive diets rarely achieve.

The mechanism: blocking myostatin

No chemical stimulation or magic pills — according to its technical advocates: the idea is to dampen the signal the body itself uses to avoid producing muscle. The name of that protein, myostatin, is already the holy grail of bodybuilding. Animals naturally lacking it develop extreme musculature. Although nobody expects to reach that extreme, the approach opens the door to a lean, strong body without setting foot in a gym. The tongue-in-cheek prediction that gyms will become the new video rental shops circulates as a warning to the fitness industry.

Side effects and the pharmaceutical business

Skepticism is mandatory at this stage. "It is biologically impossible for a drug to have no side effects," sums up a view widely held among those who distrust lists of wonders. Monoclonal antibodies have been used for decades, but in diseases with no alternatives, and with safety profiles that leave room for improvement. At high doses for aesthetic purposes, the question of joint, cardiovascular or metabolic damage remains unanswered.

The commercial opportunity has not gone unnoticed either. The SELECT trial, with 17,604 patients, already showed that semaglutide reduces serious cardiovascular events by 20%. If the combination with bimagrumab maintains that benefit and adds muscle, the market multiplies. The pharmaceutical companies know it.

Designer muscle will probably arrive. The fine print on long-term effects has yet to be written. Meanwhile, the cheapest way to build strength with the fewest known surprises remains lifting real iron.