Merck KGaA, a leading science and technology company, announced updated results from the global Phase 3 MANEUVER trial evaluating pimicotinib, an investigational colony stimulating factor-1 receptor (CSF-1R) inhibitor developed by Abbisko Therapeutics Co., Ltd., for the treatment of tenosynovial giant cell tumor (TGCT).

With a median follow-up of 14.3 months, pimicotinib demonstrated a notable increase in objective response rate (ORR), improving from 54 per cent at Week 25 to 76.2 per cent (95 per cent CI: 63.8, 86.0) as assessed by a blinded independent review committee (BIRC) per RECIST v1.1 criteria.

The study also reported sustained and clinically meaningful improvements in patient-reported outcomes such as pain reduction, increased range of motion, and improved physical function. The safety profile remained consistent with previously reported data, with no new safety concerns identified.

These findings were presented in the Sarcoma Mini-Oral Session (Presentation #2690MO) at the European Society for Medical Oncology (ESMO) Congress 2025.

“With the initial MANEUVER study results presented earlier this year at ASCO, pimicotinib achieved the highest objective response rate observed in a Phase 3 clinical trial of a systemic therapy for TGCT,” said Prof. Niu Xiaohui, Director of the Bone and Soft Tissue Tumour Diagnosis and Research Centre at Beijing Jishuitan Hospital. “These new data build upon that success, showing that tumor responses deepen over time while patients experience sustained improvements in function and pain relief—demonstrating pimicotinib’s potential as a best-in-class systemic therapy for TGCT.”

“TGCT affects every aspect of a patient’s life—from physical pain and stiffness to their ability to work, care for family, and engage socially,” said Sydney Stern, PhD, MS, of TGCT Support, a program of the Life Raft Group. “Pimicotinib offers hope by reducing symptoms and tumor size, helping patients regain control of their lives and maintain their roles as parents, partners, and caregivers.”

Patients who initially received placebo and later switched to pimicotinib (n=31) also benefited, achieving an ORR of 64.5 per cent by both RECIST v1.1 and Tumor Volume Score assessments, with a median follow-up of 8.5 months.

Pimicotinib continued to show a favorable safety profile, with no new safety signals observed. Importantly, there was no evidence of cholestatic hepatotoxicity, drug-induced liver injury, or skin/hair hypopigmentation, and most treatment-emergent adverse events were mild and manageable.

“These longer-term results underscore pimicotinib’s potential to transform TGCT care by providing durable tumor reduction and meaningful improvement in patient quality of life,” said Dr. Victoria Zazulina, Head of Development Unit, Oncology, Healthcare Business, Merck KGaA, Darmstadt, Germany. “We are collaborating closely with global regulatory authorities to make this promising therapy available to patients as quickly as possible.”