Vimseltinib versus a placebo in patients with tenosynovial giant cell tumor: a plain language summary of the MOTION phase 3 trial.

What is this summary about?: This article presents a patient-friendly summary of the MOTION phase 3 clinical trial results, which were published in The Lancet in June 2024.The primary goal of the MOTION trial was to understand if treatment with a drug called vimseltinib shrank tumors more than a placebo in participants with symptomatic tenosynovial giant cell tumor, also known as TGCT, for which surgery was unlikely to provide benefit. A placebo is something that looks like the treatment being studied but does not contain any medicine.The MOTION trial compared the effects of vimseltinib versus a placebo using several different outcomes associated with TGCT. These outcomes included tumor size, active range of motion of the affected joint, and several patient-reported quality-of-life measures including physical function, stiffness, overall health, and pain.

What were the main conclusions reported by the researchers?: The trial showed that more participants treated with vimseltinib experienced significant tumor shrinkage, as defined by a 30% or greater reduction in tumor size, compared with those receiving a placebo. Participants receiving vimseltinib had improved active range of motion, and they reported improved physical function, stiffness, overall health, and pain, regardless of the amount of tumor shrinkage, compared with participants receiving a placebo. Most side effects in participants treated with vimseltinib were not severe and were manageable.

What are the key takeaways?: Vimseltinib was better at shrinking tumors and improving active range of motion, stiffness, pain, and other health measures than the placebo for participants with TGCT. Vimseltinib has the potential to become a new treatment option for patients with TGCT for whom surgery may not provide benefit.