Abbisko’s pimicotinib secures FDA approval for symptomatic TGCT after Phase III MANEUVER results showed a 56% response rate versus 3.2% with placebo.
Written By: Siddhi Bhadekar, M. Pharm (QA)
Reviewed By: Pharmacally Editorial Team
The U.S. Food and Drug Administration (FDA) approved PIMJETMI® (pimicotinib), an oral colony-stimulating factor 1 receptor (CSF-1R) inhibitor, on November 10, 2026, for adults with symptomatic tenosynovial giant cell tumor (TGCT) for whom surgical resection may cause worsening functional limitation or severe morbidity. Abbisko Therapeutics, which independently developed the drug, announced the approval on November 11. Merck KGaA, Darmstadt, Germany which operates its U.S. biopharmaceutical business as EMD Serono, Inc. holds global commercialization rights.
Regulatory Pathway and Global Approvals
The approved indication addresses patients whose symptomatic TGCT cannot be adequately managed through surgery without potentially substantial functional consequences. The recommended dosage is 50 mg orally once daily, with or without food.
Pimicotinib received FDA Fast Track and Breakthrough Therapy designations. Its application was reviewed under Project Orbis, which facilitated collaboration with regulatory authorities in Australia, Canada, Israel, Switzerland, and the United Kingdom, with the European Medicines Agency (EMA) participating as an official observer.
The U.S. approval represents the fourth marketing authorization for pimicotinib, following approvals in China in December 2025, Canada in June 2026, and Switzerland in October 2026.
Phase III MANEUVER Demonstrated Significant Tumor Responses
Approval was supported by the international Phase III MANEUVER trial (NCT05804045), a randomized, double-blind, placebo-controlled study conducted across 40 centers in Asia, Europe, and North America. The trial enrolled 94 adult patients with symptomatic TGCT and at least one measurable lesion of 2 cm or larger for whom surgery could cause significant functional impairment or complications.
Participants were randomized 2:1 to receive pimicotinib 50 mg once daily () or placebo () during the 24-week double-blind phase (Part 1), followed by open-label treatment (Part 2) and long-term extension (Part 3). The primary endpoint was objective response rate (ORR) at week 25, assessed by blinded independent central review according to RECIST v1.1.
Pimicotinib achieved an ORR of 56% (95% CI, 42–68), compared with 3.2% (95% CI, 0.1–17) with placebo ().
The treatment also demonstrated statistically significant improvements across key secondary endpoints, including active range of motion of the affected joint measured by goniometry (), physical functioning assessed via the PROMIS-PF scale (), and worst pain measured by the Brief Pain Inventory numeric rating scale (). These findings extend the clinical evidence beyond tumor shrinkage to outcomes directly relevant to patients’ daily functioning.
Longer-Term Follow-up Indicates Sustained Responses
Additional follow-up from the open-label and extension phases provided evidence of response durability. The FDA reported that median duration of response (DOR) had not been reached in the pimicotinib arm. Among responders, 32 (91%) had a DOR of at least six months, while 27 (77%) maintained a response for at least 12 months.
These findings support sustained antitumor activity, although ongoing follow-up will be necessary to establish the durability of benefit over extended treatment periods.
Safety Profile and FDA Warnings
The most common adverse reactions occurring in more than 20% of patients were pruritus, rash, face edema, periorbital edema, fatigue, nausea, headache, and peripheral edema.
Laboratory abnormalities occurring in more than 30% of patients included increased creatine phosphokinase, lactate dehydrogenase, aspartate aminotransferase, lipase, cholesterol, amylase, and alanine aminotransferase.
The FDA prescribing information also includes warnings and precautions for hepatotoxicity, embryo-fetal toxicity, and increased serum creatinine without affecting renal function. Clinicians are advised to perform periodic liver function test monitoring during treatment, and patients of reproductive potential—as well as male patients with female partners of reproductive potential should use effective contraception during therapy and avoid breastfeeding.
Drug Development and Commercialization
Pimicotinib is an orally administered, small-molecule CSF-1R inhibitor independently developed by Abbisko. Under a December 2023 agreement, Merck KGaA, Darmstadt, Germany received global commercialization rights. Abbisko is eligible for a milestone payment following the first U.S. commercial sale, double-digit royalties on global net sales, and additional potential development, regulatory, and commercial milestones.
TGCT is a rare, locally aggressive tumor affecting joints, tendon sheaths, and bursae. Overexpression of colony-stimulating factor 1 (CSF-1) in neoplastic synovial cells promotes the accumulation of CSF-1R-expressing inflammatory cells within tumors. By inhibiting CSF-1R, pimicotinib targets this disease-associated signaling pathway.
Clinical Interpretation
MANEUVER provides randomized evidence that pimicotinib can produce substantial tumor responses while improving joint mobility, physical functioning, and pain. These outcomes are particularly relevant in TGCT, where preserving joint function and reducing disease-related disability are primary treatment objectives.
However, the safety profile requires attentive management, particularly regarding liver enzyme elevations and FDA warnings concerning hepatotoxicity and embryo-fetal toxicity. Longer-term follow-up will also be important to establish cumulative safety, sustained disease control, and outcomes following treatment discontinuation.
Pimicotinib now adds a third systemic CSF-1R inhibitor option for adults with symptomatic TGCT for whom surgery carries substantial risks. Its clinical positioning alongside pexidartinib which carries a boxed warning for hepatotoxicity and requires a Risk Evaluation and Mitigation Strategy (REMS) program and vimseltinib which is administered twice weekly without a REMS will depend on individual patient risk profiles, monitoring requirements, and dosing preferences, as available MANEUVER findings do not establish comparative superiority among these agents.
References
Abbisko Therapeutics. PIMJETMI® (pimicotinib) Developed by Abbisko Therapeutics and Licensed by Merck KGaA, Darmstadt, Germany Receive U.S. FDA Approval for TGCT. November 10, 2026.
U.S. Food and Drug Administration. FDA approves pimicotinib for symptomatic tenosynovial giant cell tumor, US FDA, November 10, 2026.
ClinicalTrials.gov. Study of Pimicotinib (ABSK021) for Tenosynovial Giant Cell Tumor (MANEUVER), NCT05804045.
About the Writer
Siddhi Rajendra Bhadekar (Linkedin) is an M.Pharm professional with expertise in medical and scientific writing, literature review, publication writing, and evidence synthesis, supported by four peer-reviewed publications.
She brings working knowledge of ICH-GCP, MedDRA, pharmacovigilance, ADR/AE reporting, clinical data management, and regulatory documentation.
With experience across pharmaceutical R&D, Quality Control, and Quality Assurance, she combines scientific research skills with strong attention to accuracy and detail.
Her background in manuscript development, publication planning, and scientific communication enables her to translate complex healthcare information into clear, reliable content.