Pimicotinib
An investigational treatment for Tenosynovial Giant Cell Tumor.
Drug facts
The same compound appears under different names depending on the context. Here is how to identify Pimicotinib wherever you encounter it, plus the key facts at a glance.
- Generic name
- Pimicotinib
- Development code
- ABSK021
- Drug class
- CSF1R kinase inhibitor
- Manufacturer
- Abbisko Therapeutics; worldwide commercialization rights held by Merck KGaA, Darmstadt, Germany (EMD Serono in the US and Canada)
- How it's taken
- Oral, once a day, under FDA review
Pimicotinib is an investigational once-daily pill from Abbisko Therapeutics for tenosynovial giant cell tumor (TGCT), under FDA review with no decision date disclosed[5][6].
- Merck KGaA, Darmstadt, Germany, whose healthcare business is called EMD Serono in the US and Canada, holds worldwide commercialization rights[6].
- In the Phase 3 MANEUVER trial, tumors shrank in 54% of people on pimicotinib by week 25 against 3% on placebo[1].
- China approved it in December 2025 and Canada in June 2026, according to Merck KGaA[6].
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Where Pimicotinib fits
Pimicotinib is an investigational once-daily pill under FDA review for tenosynovial giant cell tumor (TGCT), and it blocks CSF1R, the same receptor targeted by the 2 approved TGCT medicines[5][1].
- Surgery remains the first treatment for TGCT, but many people have tumors that cannot be removed or that come back, and these can cause lasting joint problems[7].
- Turalio (pexidartinib), approved in 2019, and Romvimza (vimseltinib), approved in 2025, are the FDA-approved medicines for people whose TGCT surgery cannot help or could harm[8][10].
- MANEUVER compared pimicotinib with placebo, and no trial comparing pimicotinib directly with Turalio or Romvimza appears on ClinicalTrials.gov[1][2].
- Anyone curious about pimicotinib can ask a TGCT specialist whether surgery, an approved CSF1R medicine or a clinical trial best fits their tumor and joint.
How Pimicotinib works
Tenosynovial giant cell tumor grows in the lining of a joint or tendon sheath. The tumor is driven by too much of a signal called CSF1, which draws in macrophages and other inflammatory cells that carry its receptor, CSF1R, and those cells build up the tumor[7]. Pimicotinib is a highly selective drug that blocks CSF1R, which is meant to cut off that signal so the tumor can shrink[1]. Turalio (pexidartinib) and Romvimza (vimseltinib), the 2 FDA-approved TGCT medicines, work on the same receptor[8][9].
Clinical trial results
MANEUVER (NCT05804045) is a Phase 3, double-blind trial run at 40 hospitals in Asia, Europe and North America[1]. It randomized 94 adults with symptomatic TGCT that could not be removed by surgery, 63 to pimicotinib 50mg once a day and 31 to placebo, for 24 weeks, followed by an open-label part in which everyone could take pimicotinib[1].
By week 25, tumors shrank by the standard RECIST measure in 54% of people on pimicotinib (34 of 63) against 3% on placebo (1 of 31), as judged by reviewers who did not know who got which treatment[1]. By tumor volume score, a measure of total tumor size, 61.9% responded against 3.2%[2]. Active range of motion in the affected joint improved by an average of 15.6% on pimicotinib against -0.07% on placebo[2].
On 0 to 10 scales, worst stiffness fell by 3.0 points against 0.6, and worst pain fell by 2.3 points against 0.2[2]. Physical function scores (PROMIS) rose by 5.6 points against 2.2[2].
At the 2-year follow-up, presented at ESMO 2026, 76.2% of the people first assigned to pimicotinib had a RECIST response, and range of motion was 19.6% better than at the start at week 97[6]. Of those first assigned to pimicotinib, 54% were still taking it at 2 years[6]. The 2-year figures have no placebo group to compare with, because the placebo group could switch to pimicotinib after week 25[1].
J-MANEUVER (NCT07499362) is a Phase 2, single-arm study of pimicotinib in about 20 Japanese adults with TGCT, run by Merck KGaA. It began on March 26, 2026 and is recruiting[3].
Main registered trial: NCT05804045 on ClinicalTrials.gov. Check it for the current status, sites and contacts before asking about enrollment.
Side effects and safety
Pimicotinib has no FDA label, so its official side effects and warnings are not set yet[6]. In the 24-week blinded part of MANEUVER, the most common side effects on pimicotinib compared with placebo were itching (52% against 3%), face swelling (48% against 0%), rash (35% against 0%), swelling around the eyes (32% against 10%), fatigue (29% against 23%), nausea (27% against 6%) and headache (21% against 6%)[2].
Blood test changes were common. Creatine phosphokinase (CPK), a muscle enzyme, rose in 71% of people on pimicotinib against 16% on placebo, the liver enzyme AST in 54% against 10%, and LDH in 57% against 0%[2]. A CPK rise of grade 3 or 4 occurred in 13% of people on pimicotinib, and it was the only grade 3 or 4 side effect seen in more than 10%[1].
Serious side effects occurred in 3 of 63 people on pimicotinib (4.8%) and 1 of 31 on placebo (3.2%)[2]. The dose was lowered for 8% of people on pimicotinib, and 1 person (2%) stopped because of side effects[1]. The investigators reported no cholestatic liver injury (damage that blocks bile flow), no drug-induced liver injury and no loss of skin or hair color during that period[1]. Merck KGaA's October 26, 2026 update reported no evidence of cholestatic liver injury or loss of skin or hair color in MANEUVER[6].
This is not a complete list of side effects. Talk to your doctor or pharmacist about what to expect and when to seek medical attention.
Taking Pimicotinib
In MANEUVER, people took 50mg of pimicotinib by mouth once a day[1]. The J-MANEUVER study in Japan uses the same 50mg once-daily dose in 28-day cycles[3]. The FDA has not yet approved a dose, so food instructions, dose reductions and monitoring will not be set until a US label is published[6].
Development history
Abbisko Therapeutics developed pimicotinib under the code ABSK021 and funded MANEUVER, which began enrolling on April 27, 2023[1][2]. Merck KGaA, Darmstadt, Germany, holds worldwide commercialization rights[6]. China's National Medical Products Administration approved pimicotinib for TGCT in December 2025[5]. EMD Serono announced in January 2026 that the FDA had accepted its New Drug Application for TGCT[5].
The FDA has given pimicotinib Breakthrough Therapy designation for inoperable TGCT, and the European Medicines Agency has given it PRIME designation[5]. The MANEUVER results were published in The Lancet in March 2026[1]. Merck KGaA said on October 26, 2026 that Health Canada had approved pimicotinib in June 2026 and that the US application was still under FDA review, with no decision date disclosed[6]. Abbisko has also registered a Phase 2 study of pimicotinib in chronic graft-versus-host disease[4].
Explore Tenosynovial Giant Cell Tumor trials
Other Tenosynovial Giant Cell Tumor treatments
Common questions about Pimicotinib
▸What is Pimicotinib?
Pimicotinib is an investigational once-daily pill from Abbisko Therapeutics for tenosynovial giant cell tumor (TGCT), under FDA review with no decision date disclosed[5][6]. Merck KGaA, Darmstadt, Germany, whose healthcare business is called EMD Serono in the US and Canada, holds worldwide commercialization rights[6]. In the Phase 3 MANEUVER trial, tumors shrank in 54% of people on pimicotinib by week 25 against 3% on placebo[1]. China approved it in December 2025 and Canada in June 2026, according to Merck KGaA[6].
▸How does Pimicotinib work?
Tenosynovial giant cell tumor grows in the lining of a joint or tendon sheath. The tumor is driven by too much of a signal called CSF1, which draws in macrophages and other inflammatory cells that carry its receptor, CSF1R, and those cells build up the tumor[7]. Pimicotinib is a highly selective drug that blocks CSF1R, which is meant to cut off that signal so the tumor can shrink[1]. Turalio (pexidartinib) and Romvimza (vimseltinib), the 2 FDA-approved TGCT medicines, work on the same receptor[8][9].
▸What are the side effects of Pimicotinib?
Pimicotinib has no FDA label, so its official side effects and warnings are not set yet[6]. In the 24-week blinded part of MANEUVER, the most common side effects on pimicotinib compared with placebo were itching (52% against 3%), face swelling (48% against 0%), rash (35% against 0%), swelling around the eyes (32% against 10%), fatigue (29% against 23%), nausea (27% against 6%) and headache (21% against 6%)[2]. Blood test changes were common. Creatine phosphokinase (CPK), a muscle enzyme, rose in 71% of people on pimicotinib against 16% on placebo, the liver enzyme AST in 54% against 10%, and LDH in 57% against 0%[2]. A CPK rise of grade 3 or 4 occurred in 13% of people on pimicotinib, and it was the only grade 3 or 4 side effect seen in more than 10%[1]. Serious side effects occurred in 3 of 63 people on pimicotinib (4.8%) and 1 of 31 on placebo (3.2%)[2]. The dose was lowered for 8% of people on pimicotinib, and 1 person (2%) stopped because of side effects[1]. The investigators reported no cholestatic liver injury (damage that blocks bile flow), no drug-induced liver injury and no loss of skin or hair color during that period[1]. Merck KGaA's October 26, 2026 update reported no evidence of cholestatic liver injury or loss of skin or hair color in MANEUVER[6].
▸How is Pimicotinib taken?
▸Is Pimicotinib FDA approved?
Not yet. Pimicotinib is under FDA review for Tenosynovial Giant Cell Tumor; Merck KGaA, Darmstadt, Germany has filed an application and a decision is pending. The FDA calendar page tracks the outcome.
▸Is pimicotinib FDA approved?
No. Pimicotinib is under FDA review for tenosynovial giant cell tumor and has no US approval.
Status: EMD Serono announced in January 2026 that the FDA had accepted its application. Merck KGaA said on October 26, 2026 that the review was still ongoing.
Decision date: Merck KGaA has not disclosed one.
Elsewhere: China approved it in December 2025 and Canada in June 2026, according to Merck KGaA.
Source: Merck KGaA, October 26, 2026; EMD Serono, January 2026
▸What did the MANEUVER trial of pimicotinib show?
Tumors shrank in 54% of people on pimicotinib by week 25, against 3% on placebo.
Who was studied: 94 adults with symptomatic TGCT that surgery could not remove, at 40 hospitals in Asia, Europe and North America.
Joint movement: Range of motion improved by an average of 15.6% on pimicotinib, with almost no change on placebo.
Pain and stiffness: On 0 to 10 scales, worst pain fell 2.3 points against 0.2, and worst stiffness 3.0 points against 0.6.
After 2 years: 76.2% of people first assigned to pimicotinib had a tumor response, with no placebo group left to compare.
Source: Xu et al., The Lancet, 2026; ClinicalTrials.gov NCT05804045 results
▸Does pimicotinib affect the liver?
MANEUVER found no cholestatic or drug-induced liver injury through week 25, though liver and muscle enzyme rises were common in blood tests.
Liver: The investigators reported no cholestatic liver injury and no drug-induced liver injury. AST rose in 54% of people on pimicotinib against 10% on placebo.
Muscle enzyme: CPK rose in 71% against 16%, and 13% had a grade 3 or 4 rise.
Later update: Merck KGaA's October 26, 2026 release reported no evidence of cholestatic liver injury in MANEUVER.
No label yet: Monitoring rules will be set only if the FDA approves it.
Source: Xu et al., The Lancet, 2026; ClinicalTrials.gov NCT05804045 results
▸How is pimicotinib different from Turalio and Romvimza?
All 3 block CSF1R, but they are taken on different schedules, and no trial has compared them directly.
Pimicotinib: 50mg once a day in MANEUVER, under FDA review.
Turalio: Twice a day with a low-fat meal, with a boxed warning for liver injury and a REMS program, according to its label.
Romvimza: Twice a week, with no boxed warning, according to its label.
Comparison: Each drug was tested against placebo in its own trial, and results from different trials cannot be lined up as a contest.
Source: Xu et al., The Lancet, 2026; Turalio label, DailyMed; Romvimza label, DailyMed
Sources and references
Every factual claim on this page is drawn from the public sources listed below. Click any reference to open the original document.
- The Lancet · 2026-03-05. Pimicotinib versus placebo for tenosynovial giant cell tumour (MANEUVER): an international, randomised, placebo-controlled, phase 3 trial.. https://pubmed.ncbi.nlm.nih.gov/41796601/
- ClinicalTrials.gov · 2026-05-04. Study of Pimicotinib (ABSK021) for Tenosynovial Giant Cell Tumor (MANEUVER). https://clinicaltrials.gov/study/NCT05804045
- ClinicalTrials.gov · 2026-10-23. Study of Pimicotinib in Japanese Participants With Tenosynovial Giant Cell Tumor (TGCT) (J-MANEUVER). https://clinicaltrials.gov/study/NCT07499362
- ClinicalTrials.gov. A Phase II Study Evaluating the Efficacy and Safety of ABSK021 (Pimicotinib)) in the Treatment of cGvHD Chronic Graft Versus Host Disease (cGvHD). https://clinicaltrials.gov/study/NCT06186804
- EMD Serono via Business Wire (BioSpace copy) · 2026-01-12. FDA Accepts New Drug Application for Pimicotinib for the Treatment of Tenosynovial Giant Cell Tumor. https://www.biospace.com/press-releases/fda-accepts-new-drug-application-for-pimicotinib-for-the-treatment-of-tenosynovial-giant-cell-tumor
- Merck KGaA, Darmstadt, Germany via Business Wire (STT copy) · 2026-10-26. Two-Year Data of Pimicotinib Demonstrated Durable Tumor Control and Sustained Improvement in TGCT Symptoms and Joint Function. https://www.sttinfo.fi/tiedote/72444131/two-year-data-of-pimicotinib-demonstrated-durable-tumor-control-and-sustained-improvement-in-tgct-symptoms-and-joint-function?publisherId=58763726
- Expert Review of Anticancer Therapy · 2026-01-24. Management of tenosynovial giant cell tumor: approved and investigational therapies.. https://pubmed.ncbi.nlm.nih.gov/41557367/
- U.S. National Library of Medicine, DailyMed · 2025-01. TURALIO (pexidartinib) capsules: Prescribing Information. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=7b0ec4bf-b2ac-49ee-96af-7740ad3f2e16
- U.S. National Library of Medicine, DailyMed · 2026-06. ROMVIMZA (vimseltinib) capsules: Prescribing Information. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=f73c7a62-9601-4df0-810f-100f515d79ea
- U.S. Food and Drug Administration · 2025-02-14. FDA approves vimseltinib for symptomatic tenosynovial giant cell tumor. https://www.fda.gov/drugs/cancer-approvals/fda-approves-vimseltinib-symptomatic-tenosynovial-giant-cell-tumor