Could vimseltinib be the next big thing in TGCT treatment? FDA says Yes!

The U.S. Food and Drug Administration (FDA) has granted priority review status to Deciphera Pharmaceuticals, Inc.’s New Drug Application (NDA) for vimseltinib, a drug developed to treat tenosynovial giant cell tumor (TGCT). The FDA’s target action date for this review is February 17, 2025. This development follows the European Medicines Agency’s (EMA) acceptance of Deciphera’s Marketing Authorization Application (MAA) for vimseltinib in July 2024, marking a significant step in the drug’s regulatory journey.

Vimseltinib’s Pivotal Phase 3 MOTION Study Results

The application is bolstered by compelling data from the pivotal Phase 3 MOTION study. This study was designed to evaluate the efficacy and safety of vimseltinib in patients with TGCT who are not candidates for surgery and have not received prior anti-CSF1/CSF1R therapy. The study demonstrated that vimseltinib achieved a statistically significant and clinically meaningful objective response rate (ORR) compared to placebo. Specifically, 40% of patients treated with vimseltinib exhibited a positive response at Week 25, contrasted with 0% in the placebo group (p < 0.0001). The drug also showed substantial improvements across all key secondary endpoints, including tumor volume score (TVS), range of motion (ROM), and quality of life measures.

The MOTION study results were presented at the 2024 American Society of Clinical Oncology (ASCO) Annual Meeting and published in The Lancet. These results underscore vimseltinib’s potential as a significant new therapeutic option for TGCT patients, particularly those who are not eligible for surgery.

Study Design and Methodology

The MOTION study is a two-part, randomized, double-blind, placebo-controlled Phase 3 trial. The primary endpoint is the ORR at Week 25, evaluated by Blinded Independent Radiologic Review (BIRR) per Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST v1.1). Secondary endpoints include tumor volume score (TVS), range of motion (ROM), physical function, stiffness, quality of life, and pain. The study’s design includes 24 weeks of treatment with either vimseltinib or placebo, followed by an open-label extension phase for patients initially receiving placebo.

Background on Tenosynovial Giant Cell Tumor (TGCT)

Tenosynovial giant cell tumor (TGCT) is a rare, non-malignant tumor that arises near or within joints, characterized by an overproduction of colony-stimulating factor 1 (CSF1) due to a genetic translocation. TGCT, also known as giant cell tumor of the tendon sheath (GCT-TS) or pigmented villonodular synovitis (PVNS), can cause significant pain, swelling, and joint dysfunction. While typically benign, these tumors can cause considerable discomfort and disability, particularly when they recur or are not amenable to surgical intervention. Existing treatment options are limited, highlighting the need for new systemic therapies.

Vimseltinib: A New Hope

Vimseltinib is an investigational, oral switch-control tyrosine kinase inhibitor designed to selectively inhibit CSF1R. Developed using Deciphera Pharmaceuticals’ proprietary switch-control kinase inhibitor platform, vimseltinib targets the CSF1R pathway, which is implicated in the pathogenesis of TGCT. The drug’s development reflects Deciphera’s commitment to advancing innovative cancer treatments, including its approved drug QINLOCK, a switch-control inhibitor for gastrointestinal stromal tumors (GIST).

The data from the MOTION study is promising and could offer a new therapeutic option for TGCT patients who have limited treatment choices. Vimseltinib’s efficacy in this study is a significant advancement in addressing the unmet need in TGCT treatment.