20 October 2025, Shanghai – Abbisko Therapeutics Co. Ltd. (Abbisko Therapeutics 00256.HK) announced that longer-term efficacy and safety outcomes from the global phase III MANEUVER trial of pimicotinib (ABSK021) in patients with tenosynovial giant cell tumour (TGCT) were presented at the ESMO Congress 2025.

This longer-term analysis demonstrated that tumour responses to pimicotinib, as assessed by objective response rate (ORR) by blinded independent review committee (BIRC) per RECIST v1.1 and tumor volume score (TVS) continued to deepen and improve with time and were durable, with ongoing clinically meaningful improvements in clinical outcome assessments (COAs; including range of motion, stiffness, pain, and physical function), and a safety profile consistent with previous analyses, supporting the feasibility of longer-term treatment.

Figure 1. Photo of oral presentation from ESMO

TGCT is a rare mesenchymal 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.

Pimicotinib is a novel, oral, highly selective, and potent small-molecule CSF-1R inhibitor independently developed by Abbisko Therapeutics. Its global phase III MANEUVER trial consists of three parts and is designed to evaluate the efficacy and safety of pimicotinib in patients with TGCT. The results from Part 1 of MANEUVER trial, presented at the 2025 ASCO Annual Meeting, showed that pimicotinib provided significant efficacy benefits for patients. At week 25, the objective response rate (ORR) assessed by blinded independent review committee (BIRC) per RECIST v1.1 was 54% in the pimicotinib treatment group, compared to only 3.2% in the placebo control group.

Figure 2. MANEUVER trial design

At the ESMO Congress 2025, Prof. Xiaohui Niu from Beijing Jishuitan Hospital, leading principal investigator (PI) of MANEUVER trial, reported the longer-term efficacy and safety outcomes. With a median follow-up of 14.3 months, the ORR assessed by BIRC per RECIST v1.1 in patients treated with pimicotinib since the beginning of the study increased to 76.2% (95% CI: 63.8, 86.0), with the median duration of response (mDOR) not yet reached (range: 0.03-19.81 months). At the end of Part 2 (week 49), the COAs showed ongoing improvements (Table 1) with a good safety profile. Up to Week 73, pimicotinib showed a mean change from baseline of 23.9% in relative range of motion. Patients who were randomized to placebo in Part 1 and then switched to pimicotinib in Part 2 also achieved benefit, with an ORR of 64.5% by both BICR per RECIST v1.1 and TVS, as well as improvements in COAs.

Table 1. COAs at the end of Part 2 (Week 49) for patients randomized to pimicotinib at baseline

As accumulating data further validate the efficacy, safety, and tolerability of pimicotinib in the longer-term management of TGCT, its potential to become a best-in-class therapy and its commercial value are poised for progressive realization.

About Pimicotinib

Pimicotinib is a novel, oral, highly selective, and potent small-molecule CSF-1R inhibitor independently developed by Abbisko Therapeutics. Positive top-line results from the global Phase III MANEUVER study of pimicotinib for the treatment of tenosynovial giant cell tumor (TGCT) were announced in November 2024. Currently, pimicotinib has been included in the priority review process by the Center for Drug Evaluation (CDE) of the National Medical Products Administration (NMPA) in China for the treatment of adult TGCT patients requiring systemic therapy. Pimicotinib also has been granted breakthrough therapy designation (BTD) by the NMPA. In December 2023, Abbisko entered into an agreement with Merck KGaA, Darmstadt, Germany, pertaining to the commercial rights to pimicotinib, pursuant to which Merck KGaA, Darmstadt, Germany, is responsible for the commercialization of pimicotinib globally.

Outside of China, pimicotinib has been granted Breakthrough Therapy Designation by the US Food and Drug Administration (FDA) and PRIME Designation by the European Medicines Agency (EMA).

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.