Tenosynovial giant cell tumor, also known as pigmented villonodular synovitis (PVNS) or giant cell tumor of the tendon sheath (GCT-TS), is primarily treated through surgical resection. For localized TGCT, the typical approach involves direct removal of the tumor nodule. In contrast, diffused-type TGCT (DTGCT) tends to present as larger tumors affecting major joints, making treatment more complex. Management options for DTGCT often include total synovectomy, joint replacement, or, in extremely rare cases, amputation.

Among the 7MM, the United States had the highest prevalence of tenosynovial giant cell tumor, accounting for approximately 45% of total cases. In 2023, localized TGCT in the U.S. was most commonly found in the digits, representing around 75% of cases. Depending on whether the tumor is localized or diffuse, giant cell tumors can also occur in the knee, ankle, hip, and other areas. According to DelveInsight analysts, diffuse TGCT was most frequently observed in the knee, with an estimated 30,000 cases in the US in 2023.

The primary approach to treating TGCT is surgery, often supplemented by alternative options like Radiation Therapy, Radiosynovectomy, and Systemic Therapies, including CSF1 inhibitors and Tyrosine Kinase Inhibitors. TURALIO (pexidartinib, previously known as PLX3397) is a targeted therapy developed by Daiichi Sankyo for adult patients with symptomatic tenosynovial giant cell tumor that leads to significant morbidity or functional limitations and cannot be effectively treated with surgery. 

This orally administered small-molecule tyrosine kinase inhibitor acts on colony-stimulating factor 1 receptor (CSF1R), KIT proto-oncogene receptor tyrosine kinase (KIT), and FMS-like tyrosine kinase 3 (FLT3) with an internal tandem duplication (ITD) mutation. Overexpression of the CSF1R ligand contributes to excessive cell proliferation and accumulation in the synovium.  

The US FDA approved TURALIO in August 2019 for the treatment of TGCT in adults with severe symptoms and limited surgical options. Before this, in October 2015, pexidartinib received Breakthrough Therapy Designation (BTD) from the FDA for TGCT treatment. TURALIO carries a risk of serious and potentially life-threatening liver toxicity and is available only through a restricted Risk Evaluation and Mitigation Strategy (REMS) program.