FDA Approves Vimseltinib for Symptomatic Tenosynovial Giant Cell Tumor

On February 14, 2025, the Food and Drug Administration (FDA) announced the approval of vimseltinib, marketed as Romvimza by Deciphera Pharmaceuticals, LLC. This new treatment is a kinase inhibitor specifically designed for adult patients suffering from tenosynovial giant cell tumor (TGCT) when surgery might exacerbate functional limitations or lead to severe health complications. Detailed prescribing information for Romvimza will be made available on the FDA's Drugs@FDA website.

The approval of vimseltinib stems from its efficacy as demonstrated in the MOTION clinical trial (NCT05059262), a double-blind, multicenter, and placebo-controlled study. This trial enrolled patients diagnosed with TGCT, who presented measurable disease according to the RECIST v1.1 criteria, and possessed at least one tumor lesion measuring 2 cm or larger. The trial aimed to evaluate the effectiveness of vimseltinib in patients where surgical options could result in further functional impairment or critical health issues.

During the study, participants were randomly assigned in a 2:1 ratio to receive either vimseltinib or a placebo over a span of 24 weeks in the double-blind phase, referred to as Part 1. Following this phase, the trial entered an open-label phase (Part 2), where patients initially on placebo were given the option to switch to vimseltinib. The assignment was stratified by the tumor’s location, differentiating between the lower limb and other areas, and by geographical region, distinguishing between the United States and other countries. In total, 123 patients participated, with 83 receiving vimseltinib and 40 on placebo during the first phase.

The primary measure of efficacy focused on the overall response rate (ORR), which was evaluated through a blinded independent radiological review at the 25-week mark. Results revealed a significant ORR of 40% in the vimseltinib group compared to 0% in the placebo group. The statistical significance of these results, indicated by a p-value of less than 0.0001, underscores the drug’s potential. Moreover, the median duration of response (DOR) had not been reached in the vimseltinib group after an additional six months of observation. Notably, 28 responders, accounting for 85%, maintained a response for at least six months, and 19 responders, or 58%, for nine months or more. The significant primary outcome was further backed by notable improvements in the active range of motion, patient-reported physical functioning, and pain reduction in the vimseltinib group, as compared to those on placebo.

Common adverse reactions observed in at least 20% of participants included laboratory abnormalities such as elevated aspartate aminotransferase levels, along with periorbital edema, fatigue, rash, increased cholesterol levels, peripheral and facial edema, reduced neutrophil and leukocyte counts, pruritus, and elevated alanine aminotransferase levels.

The recommended dosage for vimseltinib is 30 mg to be taken orally twice a week, ensuring a minimum interval of 72 hours between doses. This approval process benefited from the Assessment Aid, which is a voluntary submission from the applicant to facilitate the FDA’s evaluation. Furthermore, this application was given priority review status.