Merck Receives Approval for Pimicotinib in Rare Joint Tumour Tenosynovial Giant Cell Tumour (TGCT)
Tuesday, December 23, 2025
Merck has secured the world’s first regulatory approval for pimicotinib as a systemic treatment for adults with symptomatic tenosynovial giant cell tumour (TGCT) in China.
Pimicotinib is a colony-stimulating factor-1 receptor (CSF-1R) inhibitor and represents the first Class 1 chemical drug approved in China specifically for the treatment of TGCT. The therapy offers a new option for patients who previously had limited alternatives beyond surgery, particularly in recurrent or inoperable cases.
TGCT is a rare but locally aggressive tumour that affects the joints, causing swelling, stiffness, pain and reduced mobility. If not treated effectively, it can lead to long-term damage to bones, joints and surrounding tissues, significantly affecting quality of life. The condition has also been historically referred to as pigmented villonodular synovitis (PVNS).
Granted by the China National Medical Products Administration under Priority Review, the approval covers patients for whom surgery is not appropriate or may lead to functional limitation or significant morbidity, marking an important advance in the treatment of this rare joint condition.
The approval is based on results from the global Phase 3 MANEUVER study, which evaluated the efficacy and safety of pimicotinib in patients requiring systemic treatment. In the study, pimicotinib showed the highest objective response rate reported to date in a Phase 3 trial for a systemic TGCT therapy. At week 25, the objective response rate assessed using RECIST v1.1 criteria was 54.0% in the pimicotinib group, compared with 3.2% in the placebo group, demonstrating a statistically significant benefit.
In addition to tumour response, pimicotinib showed meaningful improvements in patient-relevant outcomes. These included better joint range of motion, improved physical function, and reductions in stiffness and pain. Longer-term follow-up data presented at the 2025 ESMO Congress showed that the objective response rate increased to 76.2% among patients who received pimicotinib from the start of the study.
The treatment was generally well tolerated. During the randomised phase of the trial, very few patients discontinued treatment due to adverse events, and dose reductions were uncommon. No signs of cholestatic liver toxicity or skin and hair pigmentation issues were observed.
With this approval, pimicotinib becomes an important new systemic treatment option for TGCT patients in China, addressing a significant unmet medical need and offering the potential for improved disease control and daily functioning.
Source: merckgroup.com
