Chugai Regains Emugrobart Rights as Roche Ends Obesity Development

Chugai Pharmaceutical Co., Ltd. (TSE: 4519) said on September 28, 2026, that Roche (OTC: RHHBY) has discontinued development of Emugrobart (GYM329) for obesity and returned all global rights to the drug to Chugai. The Japanese drugmaker said it will refocus development of Emugrobart on spinal muscular atrophy (SMA), its original indication. Financial terms of the rights transfer were not disclosed. Chugai did not specify the reason for the obesity program's termination or provide a timeline for the resumed SMA development. Chugai shares trade on the Tokyo Stock Exchange; Roche, its majority shareholder, is listed on the OTC market in the United States.