FDA Approves Pimicotinib for Rare Joint Tumor

The FDA has approved pimicotinib, sold as Pimjetmi, for adults with symptomatic tenosynovial giant cell tumor, a rare condition in which abnormal tissue growth in a joint can cause pain and limited movement. The approval applies specifically to patients whose tumors could not be safely removed by surgery without risking worse function or serious complications, according to the FDA's approval announcement.

The decision rests on the MANEUVER trial, a double blind, randomized, placebo controlled study across multiple countries. Patients received either 50 mg of pimicotinib daily or placebo. By week 25, 56 percent of those on the drug showed a confirmed response under independent review, compared with just over 3 percent on placebo. Most responders maintained that benefit for six months or longer, and many for a full year. Patients also reported meaningful gains in joint range of motion, reduced pain scores, and better physical function compared with placebo.

Side effects included itching, rash, swelling around the face and eyes, fatigue, nausea, and several laboratory abnormalities involving liver enzymes and muscle markers. The label carries warnings for liver toxicity and potential harm to a developing fetus. This approval came through Project Orbis, a framework allowing simultaneous review by regulators in several countries.

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