Vimseltinib: A novel colony stimulating factor 1 receptor (CSF1R) inhibitor approved for treatment of tenosynovial giant cell tumors (TGCTs).

A tenosynovial giant cell tumor (TGCT) is a rare benign neoplasm arising from the tendon sheaths, bursae, or synovial lining of joints and is characterized by locally aggressive growth and the potential for recurrent disease. Surgery is still the main form of treatment for a TGCT, but these neoplasms, and most notably the diffuse type, exhibit a high proclivity for recurrence, thus highlighting the unmet clinical need for novel therapeutic modalities. At the same time, a subgroup of patients deemed ineligible for surgery are confronted with limited therapeutic alternatives, further underscoring the urgent need for innovative treatment paradigms. On February 14, 2025, the US Food and Drug Administration approved a new colony-stimulating factor 1 receptor (CSF1R) inhibitor, vimseltinib, for the treatment of symptomatic TGCTs in adult patients for whom surgical resection would likely result in severe functional limitations or serious complications. As the second-in-class CSF1R inhibitor approved for TGCTs, vimseltinib exhibits enhanced selectivity for CSF1R over pexidartinib, the first-in-class agent, suggesting potential translational benefits in safety profiles. The clinical utility of vimseltinib is anticipated to be further elucidated by real-world evidence and expanded clinical evaluations.