Abbisko Therapeutics has received approval from the US Food and Drug Administration (FDA) for Pimjetmi (pimicotinib), an orally administered small-molecule colony-stimulating factor 1 receptor (CSF-1R) inhibitor, as a systemic treatment for adults with symptomatic Tenosynovial Giant Cell Tumour (TGCT) where surgical resection could result in worsening functional limitations or severe morbidity.

The approval marks the fourth regulatory authorisation for Pimjetmi, following its approval in China by the National Medical Products Administration (NMPA) in December 2025, Canada by Health Canada in June 2026, and Switzerland by the Swiss Agency for Therapeutic Products (Swissmedic) in October 2026.

Commenting on the development, Yao-Chang Xu, PhD, Founder and Chief Executive Officer, Abbisko Therapeutics, said, “The US FDA approval of Pimjetmi marks a significant milestone in Abbisko Therapeutics’ innovation and global development journey. As our first proprietary innovative medicine to reach commercialisation, Pimjetmi is now approved in China, Canada, Switzerland and the United States.”

He added that the company's global commercialisation partnership with Merck KGaA, Darmstadt, Germany, is accelerating the treatment's availability to patients worldwide. Xu further highlighted that the achievement demonstrates Abbisko's capabilities across early-stage drug discovery, global clinical development and regulatory submissions. The company will continue to focus on unmet medical needs and the development of differentiated medicines.

Danny Bar-Zohar, CEO Healthcare and Member of the Executive Board of Merck KGaA, Darmstadt, Germany, said, “People living with TGCT have long faced difficult treatment decisions as they navigate a disease that can significantly affect their daily lives, including their mobility. Translating scientific innovation into clinically meaningful advances for people living with rare tumours is a strategic imperative for our company, as we continue our commitment to addressing significant unmet needs.”

He added that the US approval strengthens Merck's position in the rare tumour segment and expands its portfolio of treatment options, offering renewed hope to patients and their families.

The US FDA approval was supported by primary and long-term results from the global Phase III MANEUVER study and its Open-Label Extension. In the trial, Pimjetmi demonstrated a statistically significant improvement in Objective Response Rate (ORR) at week 25 compared with placebo. Based on Response Evaluation Criteria in Solid Tumours (RECIST) version 1.1 and assessments by a Blinded Independent Review Committee (BIRC), the ORR was 56 percent among patients receiving Pimjetmi, compared with 3 percent in the placebo group.

The treatment also demonstrated statistically significant improvements across key secondary endpoints relevant to patients' daily lives. 

The primary findings from the MANEUVER study were presented at the 2025 American Society of Clinical Oncology (ASCO) Annual Meeting. Longer-term follow-up results, presented at the 2025 European Society for Medical Oncology (ESMO) Congress, showed sustained treatment benefits. With a median follow-up of 14.3 months among patients initially randomised to pimicotinib, the median duration of response had not been reached. Furthermore, 77% of patients who achieved a response at week 25 maintained clinical benefit after an additional 12 months of follow-up.

The regulatory applications for Pimjetmi in the US, Canada and Switzerland were reviewed under Project Orbis, an international collaboration framework initiated by the FDA's Oncology Center of Excellence. The initiative facilitates coordination among participating regulatory authorities to accelerate the review of oncology products and support the global development of innovative cancer treatments.