MPH-220

MPH-220 is an orally bioavailable, first-in-class small-molecule antispastic agent that selectively inhibits fast skeletal muscle myosin-2 to induce peripheral muscle relaxation while sparing cardiac, smooth muscle, and non-muscle myosin isoforms.[1][5] By binding in the blebbistatin-binding pocket of the myosin motor domain and stabilizing the pre-powerstroke, actin-detached state, it depresses force production in fast-twitch skeletal fibers without significant cardiovascular or respiratory effects in preclinical models.[1] Originally discovered by Motorpharma and now developed clinically as MTR-601 by Motric Bio, the drug is being advanced for focal dystonias such as cervical dystonia (torticollis) and for broader indications involving muscle spasticity and stiffness following stroke or other neurological injury.[4][5][7]