Genentech (Roche) announced it has stopped development of an experimental muscle‑building antibody after key studies failed to show consistent improvements in muscle growth and function. The company communicated the decision to patient communities and investigators, tying the termination to disappointing efficacy in a pivotal study and leaving ongoing obesity trials that relied on the same mechanism under renewed scrutiny. Roche’s move reflects rising pipeline selectivity in large pharma: groups are pruning programs that no longer meet risk‑reward thresholds. The decision will affect trial patients, internal prioritization and potential follow‑on programs aimed at muscle preservation or metabolic indications.