17 November 2025, Shanghai – Abbisko Therapeutics Co. Ltd. (Abbisko Therapeutics 00256.HK) announced the poster presentation of longer-term efficacy, safety and patient-reported outcomes from the global Phase III MANEUVER study of pimicotinib (ABSK021) in patients with tenosynovial giant cell tumour (TGCT) at the Connective Tissue Oncology Society (CTOS) 2025 Annual Meeting.

This longer-term analysis showed that sustained treatment with pimicotinib in patients with TGCT led to continued improvements in tumor response, patient-reported outcomes including pain and function, and maintained an acceptable safety profile, reinforcing its potential for long-term use in eligible patients.

TGCT is a rare and locally aggressive tumor primarily affecting joints, tendon sheaths, and bursae with potentially devastating morbidity. TGCT is driven by overexpression of colony-stimulating factor-1 (CSF-1) in neoplastic synovial cells that leads to accumulation of colony-stimulating factor-1 receptor (CSF-1R)–expressing inflammatory cells in the tumor.

The MANEUVER study is a global, multicenter, randomized, double-blind, placebo-controlled Phase III clinical trial consisting of three parts, designed to evaluate the efficacy and safety of pimicotinib in patients with TGCT. The primary endpoint and all key secondary endpoints were met in Part 1 at week 25, and the corresponding results were presented at the 2025 American Society of Clinical Oncology (ASCO) Annual Meeting. The primary endpoint is the objective response rate (ORR) at the end of Part 1, as assessed by blind independent review committee (BIRC) per RECIST v1.1. At Week 25, pimicotinib demonstrated a statistically significant improvement in ORR compared with placebo at Week 25 (54.0% vs 3.2%, P＜0.0001).

The outcomes presented at the CTOS 2025 Annual Meeting were the longer-term efficacy and safety data from the completion of Part 2 of the MANEUVER study. With a median follow-up of 14.3 months, patients who had received pimicotinib from the beginning of the study demonstrated robust and durable tumor responses. The ORR by blinded independent review committee (BIRC) per RECIST v1.1 increased from 54% at week 25 to 76.2% (95% CI: 63.8, 86.0), with four patients achieving complete response.

Meanwhile, the study also showed continued clinically meaningful improvements in clinical outcome assessments (COAs) related to TGCT patients’ quality of life, including range of motion, stiffness, pain, and physical function. The poster also presented quality of life (QoL) benefits assessed by the EQ-5D-5L visual analog scale (VAS). Patients receiving pimicotinib treatment showed a mean QoL improvement of 7.4% from baseline at Week 25, which further increased to 13.1% at Week 73.

In addition, patients who were initially randomized to the placebo arm in Part 1 and subsequently switched to pimicotinib in Part 2 also derived clinical benefit, achieving an ORR of 64.5% at a median follow-up of 8.5 months, along with notable improvements in COAs.

In terms of safety, the median dose intensity remained high at 88.2% during treatment. Most treatment-emergent adverse events (TEAEs) were Grade 1–2. No new safety signals were observed, and there was no evidence of cholestatic hepatotoxicity, drug-induced liver injury, or hair/skin hypopigmentation.

It is noteworthy that at the European Society for Medical Oncology (ESMO) Congress 2025 held in October this year, Professor Xiaohui Niu from Beijing Jishuitan Hospital, the leading principal investigator (PI) of MANEUVER study, presented these significant research findings in an oral presentation.

About Abbisko Therapeutics

Founded in April 2016, Abbisko Therapeutics Co., Ltd. (HKEX: 02256.HK), is an oncology-focused biopharmaceutical company based in Shanghai that is dedicated to the discovery and development of innovative medicines to treat unmet medical needs in China and globally. The Company was established by a group of seasoned drug hunters with rich research & development and managerial expertise from top multinational pharmaceutical companies. Since its founding, Abbisko Therapeutics has built an extensive pipeline of innovative programs focused on precision oncology and immuno-oncology.

Please visit www.abbisko.com for more information.