Neoadjuvant Pimicotinib Combined With Surgery Versus Upfront Surgery for Diffuse Tenosynovial Giant Cell Tumor

Tenosynovial giant cell tumor (TGCT) is a rare neoplasm predominantly occurring in young and middle-aged adults, characterized by high recurrence and high disability rates. Surgery represents the first-line treatment at present. Although surgical resection can eradicate lesions, repeated surgical interventions constitute the major disease-related burden. Particularly for patients with diffuse-type TGCT (D-TGCT), postoperative recurrence rates can exceed 50%.

Pimicotinib is a highly selective colony-stimulating factor 1 receptor (CSF1R) inhibitor. The phase III MANEUVER trial has verified its prominent tumor shrinkage effect and symptomatic improvement in patients with unresectable, symptomatic TGCT, with an objective response rate (ORR) of 54%. In addition, pimicotinib demonstrates a favorable safety profile; most adverse events are mild in severity, mainly including pruritus, edema, fatigue and elevated creatine kinase, without severe hepatotoxicity.

Neoadjuvant therapy followed by surgery falls within the scope of multimodal treatment, which is mostly applied to recurrent and refractory cases rather than the standard upfront regimen for treatment-naive patients. Clinical case reports and real-world observations have preliminarily validated the feasibility and clinical value of sequential systemic targeted therapy followed by surgical resection. To date, systematic and standardized clinical data regarding neoadjuvant strategies remain scarce, especially randomized controlled evidence comparing neoadjuvant targeted therapy plus surgery versus primary upfront surgery. This study aims to compare the efficacy and safety of neoadjuvant pimicotinib combined with surgery versus upfront primary surgery in the management of D-TGCT, so as to generate evidence-based rationale for developing more effective and safe therapeutic regimens for D-TGCT.