FDA Approves Pimicotinib for Symptomatic Tenosynovial Giant Cell Tumor

The FDA has approved pimicotinib (Pimjetmi) for adults with symptomatic tenosynovial giant cell tumor (TGCT) for which surgical resection may cause worsening functional limitation or severe morbidity.¹ The once-daily oral colony-stimulating factor 1 receptor (CSF-1R) inhibitor produced a 54% objective response rate (ORR) vs 3% with placebo at week 25 in the phase 3 MANEUVER trial; its label carries warnings for hepatotoxicity, embryo-fetal toxicity, and serum creatinine increases that shape nursing monitoring and education.^1,2

What is TGCT, and who is the new option for?

TGCT is a rare, locally aggressive tumor that develops in or around joints and can cause progressive swelling, stiffness, and reduced mobility; if left untreated or if it recurs, it can permanently damage bone, joints, and surrounding tissue.⁶ Surgery is the mainstay of treatment, but the approval targets patients for whom resection could worsen function or cause severe morbidity.^1,6 Pimicotinib joins the CSF-1R–directed agents vimseltinib (Romvimza) and pexidartinib (Turalio) as US systemic options.

How was pimicotinib studied in MANEUVER?

MANEUVER (NCT05804045) is a double-blind, placebo-controlled phase 3 trial conducted at 40 hospitals in Asia, Europe, and North America.^2,7 Eligible patients had symptomatic TGCT with at least 1 measurable lesion of 2 cm or larger and no prior anti-CSF-1/CSF-1R therapy.^1,3

In part 1, 94 patients were randomly assigned 2:1 to pimicotinib 50 mg once daily (n = 63) or placebo (n = 31) for 24 weeks, with randomization stratified by region (China vs non-China).^1,2 Placebo recipients could then cross over to open-label pimicotinib.²

The primary end point was ORR at week 25 by blinded independent central review per RECIST version 1.1.^2,3

How effective was pimicotinib at shrinking tumors?

The ORR at week 25 was 54% (34 of 63 patients) with pimicotinib vs 3% (1 of 31) with placebo, an absolute difference of 51% (95% CI, 33%-63%; P < .0001).²

Additional week 25 findings with pimicotinib included:

• Tumor size reduction in 92.1% of patients (58 of 63), with 1 complete response and 33 partial responses³
• ORR by tumor volume score, a TGCT-specific MRI measure, of 61.9% vs 3.2% with placebo (P < .0001)³

Responses deepened over time. At a median follow-up of 14.3 months, the ORR rose to 76.2% (95% CI, 63.8%-86.0%), and placebo recipients who crossed over had an ORR of 64.5%.⁴ In a 2-year analysis presented at the 2026 ESMO Congress (median follow-up, 22.9 months), the ORR by tumor volume score reached 77.8% and the 2-year duration of response rate was 82%.⁵

Did patients report less pain and stiffness?

Compared with placebo, pimicotinib improved active range of motion (P = .0003) and physical function measured by the PROMIS-PF scale (P = .0074) and reduced worst stiffness (P < .0001) and worst pain (P < .0001).³ Relative range of motion improved by a mean of 23.9% from baseline with longer follow-up.⁴

"In MANEUVER, we observed the highest ORR seen to date with a systemic therapy, together with statistically significant improvements in measures of pain, stiffness, and range of motion," Niu Xiaohui, director of the Bone and Soft Tissue Tumour Diagnosis and Research Centre at Beijing Jishuitan Hospital, said in a news release.³

What adverse effects should nurses watch for?

According to the FDA, the most common adverse reactions (>20%) were pruritus, rash, facial edema, periorbital edema, fatigue, nausea, headache, and peripheral edema. The most common laboratory abnormalities (>30%) were increased creatine phosphokinase (CPK), lactate dehydrogenase, aspartate aminotransferase, lipase, cholesterol, amylase, and alanine aminotransferase.¹

In part 1, the only grade 3 or 4 event in more than 10% of pimicotinib-treated patients was increased CPK (13%). Dose reductions occurred in 8% of patients, and 2% discontinued treatment.² By 2 years, 27.0% had a dose reduction and 7.9% had discontinued because of an adverse event.⁵

The recommended dose is 50 mg orally once daily, with or without food.¹

What else is known about the approval?

Pimicotinib received breakthrough therapy and fast track designations and was reviewed under Project Orbis with international regulators.¹ It was approved in China in December 2025, was developed by Abbisko Therapeutics, and is commercialized by EMD Serono.⁶

What are the key takeaways for oncology nurses?

• Monitor liver function: The label includes a hepatotoxicity warning; follow the prescribing information for liver test monitoring.¹
• Counsel on contraception: Embryo-fetal toxicity is a labeled warning; discuss reproductive plans before treatment starts.¹
• Interpret creatinine carefully: Serum creatinine may rise without a change in kidney function.¹
• Prepare patients for edema and skin effects: Facial and periorbital swelling, pruritus, and rash were among the most common reactions.¹
• Track CPK elevations: Grade 3 or 4 CPK increases occurred in 13% of patients in part 1.²
• Reinforce adherence: The once-daily oral dose can be taken with or without food.¹

References

1. FDA approves pimicotinib for symptomatic tenosynovial giant cell tumor. News release. FDA. November 10, 2026. Accessed November 10, 2026. https://www.fda.gov/drugs/cancer-approvals/fda-approves-pimicotinib-symptomatic-tenosynovial-giant-cell-tumor

2. Xu H, Niu X, Ravi V, et al. Pimicotinib versus placebo for tenosynovial giant cell tumour (MANEUVER): an international, randomised, placebo-controlled, phase 3 trial. Lancet. 2026. doi:10.1016/S0140-6736(25)02602-9

3. Pimicotinib demonstrates best-in-class potential with significant efficacy and clinically meaningful improvements in patients with tenosynovial giant cell tumor. News release. EMD Serono. May 28, 2025. Accessed November 10, 2026. https://www.emdserono.com/us-en/company/news/press-releases/phase-3-maneuver-pt-1-pimicotinib-data-28-05-2025.html

4. Pimicotinib treatment demonstrates deep and durable tumor responses and continued improvements in pain and function for patients with TGCT. News release. EMD Serono. October 17, 2025. Accessed November 10, 2026. https://www.emdserono.com/us-en/company/news/press-releases/pimicotinib-maneuver-longer-term-results-esmo-2025-17-10-2025.html

5. Gelderblom H, Ravi V, Martin Broto J, et al. Pimicotinib in patients with tenosynovial giant cell tumour: 2-year analysis of the phase 3 MANEUVER trial. Presented at: ESMO Congress 2026; October 23-27, 2026; Madrid, Spain. Poster 3747P.

6. FDA accepts new drug application for pimicotinib for the treatment of tenosynovial giant cell tumor. News release. EMD Serono. January 12, 2026. Accessed November 10, 2026. https://www.emdserono.com/us-en/company/news/press-releases/fda-accepts-new-drug-application-for-pimicotinib-12-01-2026.html

7. Study of pimicotinib (ABSK021) for tenosynovial giant cell tumor (MANEUVER). ClinicalTrials.gov identifier: NCT05804045. Accessed November 10, 2026. https://clinicaltrials.gov/study/NCT05804045