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Treatment of Tenosynovial Giant Cell Tumor with Emactuzumab

A Phase III, Multicentre, Randomised, Double-Blind Study to Assess the Safety and Efficacy of Emactuzumab vs. Placebo in Subjects With Tenosynovial Giant Cell Tumour

Phase 3 Interventional SynOx Therapeutics Limited · NCT05417789

This study is testing if a new drug called emactuzumab can help people with Tenosynovial Giant Cell Tumor who can’t have surgery feel better.

Quick facts

PhasePhase 3
Study typeInterventional
Enrollment128 (estimated)
Ages12 Years and up
SexAll
SponsorSynOx Therapeutics Limited Industry-sponsored
Drugs / interventionsnilotinib, imatinib, chemotherapy, emactuzumab
Locations44 sites (Beverly Hills, California and 43 other locations)
Trial IDNCT05417789 on ClinicalTrials.gov

What this trial studies

This multicenter, Phase 3 trial evaluates the efficacy and safety of emactuzumab in patients with localized or diffuse Tenosynovial Giant Cell Tumor (TGCT) who cannot undergo surgical removal. Participants will be randomly assigned to receive either emactuzumab or a placebo in a double-blind manner, with treatments administered intravenously every two weeks for a total of five infusions. The study includes a follow-up observation period and various assessments such as physical exams, blood tests, and imaging studies to monitor the treatment's effects. The goal is to determine if emactuzumab can provide a viable treatment option for patients with TGCT.

Who should consider this trial

Good fit: Ideal candidates are individuals over 12 years old with biopsy-confirmed localized or diffuse TGCT who are not suitable for surgical intervention.

Not a fit: Patients who are pregnant, breastfeeding, or have medical conditions requiring systemic immunosuppression may not benefit from this study.

Why it matters

Potential benefit: If successful, this treatment could offer a non-surgical option for patients suffering from TGCT, potentially improving their quality of life.

How similar studies have performed: Other studies have shown promise in treating TGCT with similar approaches, indicating potential for success.

Eligibility criteria

Show full inclusion / exclusion criteria 
Inclusion Criteria:

* Age \>12 years
* Biopsy-confirmed (standard of care diagnosis history) local or diffuse TGCT where surgical resection would be associated with predicted worsening functional limitations through surgical joint damage, and/or subject has an anticipated high risk of early recurrence as determined by a multidisciplinary tumour board or equivalent, or any other morbidity associated with the surgery, and/or surgical treatment is not expected to improve the clinical outcomes of the subject.
* Measurable disease: longest diameter ≥20 mm.
* Adequate organ and bone marrow function
* If a woman of childbearing potential (WOCBP), must have a negative pregnancy test prior to starting treatment and agree to use a highly effective method of contraception
* Participants must have given written consent

Exclusion Criteria:

* If a female, the subject is pregnant or breast feeding.
* Medical conditions, including auto-immune, requiring systemic immunosuppression. Any systemic treatment for these conditions (eg, glucocorticoids) is not allowed within 4 weeks of Screening and during the study.
* Known metastatic TGCT or other active cancer that requires concurrent or planned treatment
* Received systemic therapy for TGCT (investigational or approved) targeting CSF-1 or CSF-1R or any multi-tyrosine kinase inhibitor (eg nilotinib and imatinib) within 3 months prior to screening
* Any surgery, chemotherapy or radiotherapy within 3 months of screening
* Unresolved clinically significant toxicity from a previous treatment or any history of serious liver toxicity.
* Current or chronic history of liver disease.
* Inadequate renal and liver function
* Systemic antiretroviral therapy within 3 months of baseline
* Within 6 months of baseline has experienced: clinically significant myocardial infarction, severe/unstable angina pectoris, congestive heart failure New York Heart Association (NYHA) Class III or IV, or pulmonary disease (NYHA Criteria 1994) including severe thromboembolic event; incompletely healed clinically significant wounds, including bone fractures; pathological fracture or significant hypercalcaemia.

Where this trial is running

Beverly Hills, California and 43 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
View on ClinicalTrials.gov → Find more trials like this →
Conditions TGCTTGCT, Tenosynovial Giant Cell TumourPVNS, Pigmented Villonodular SynovitisSynovitisEmactuzumabLocal TGCTDiffuse TGCT
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.