ClinicalTrials.gg
Active, not recruitingNCT05417789TANGENTUpdated Jul 29, 2026

Study of Emactuzumab for Tenosynovial Giant Cell Tumor (TGCT)

A Phase 3 interventional study of Emactuzumab and Placebo in TGCT, sponsored by SynOx Therapeutics Limited. Active, not recruiting at 33 sites in 12 countries. Open to participants aged 12 Years and older. Per ClinicalTrials.gov, last updated 2026-07-29.

Sponsored by SynOx Therapeutics Limited · Phase 3, Interventional, and Treatment

Phase
Phase 3
Study type
Interventional
Enrollment
128
Allocation
Randomized
Ages
12 Years and older
Sex
All
01

Study summary

This is a multicenter, Phase 3, randomised, double-blind, placebo-controlled study, which aims to evaluate the efficacy and safety of the investigational drug emactuzumab for the treatment of patients with localized or diffuse TGCT where surgical removal of the tumor is not viewed as an option.

The study consists of two parts. In Part 1, eligible subjects will be assigned in a 2:1 ratio to receive either emactuzumab or matching placebo in a double-blind fashion, that will be administered in total 5 times as an intravenous (i.v.) infusion once every 2 weeks. This will be followed by an observation period of 3 months leading to a total duration of 24 weeks in Part 1. A number of assessments will be carried out during the course of the study, including physical examinations, blood tests, imaging studies, electrocardiograms, and questionnaires. Part 2 is a long-term double-blind follow-up phase of the subjects on emactuzumab or placebo. Subjects assigned to placebo in Part 1 have the option, subject to eligibility, to crossover to receive open-label emactuzumab in Part 2. Subjects assigned to active drug in Part 1 have the option to receive open-label retreatment under certain circumstances.

02

Conditions studied

  • TGCT

Keywords

  • TGCT, Tenosynovial Giant Cell Tumour
  • PVNS, Pigmented Villonodular Synovitis
  • Synovitis
  • Emactuzumab
  • Local TGCT
  • Diffuse TGCT
03

In context

Synovitis, Pigmented Villonodular

20 studies on the registry are indexed under Synovitis, Pigmented Villonodular; 2 are open to participants now.

This study's planned enrollment of 128 is above the median of 36 across 17 interventional studies indexed under Synovitis, Pigmented Villonodular.

Browse Synovitis, Pigmented Villonodular studies →

Lead sponsor

This is the only study on the registry with SynOx Therapeutics Limited as lead sponsor.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
12 Years and older
Sexes eligible
All
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • Age >12 years
  • -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.
  • : longest diameter ≥20 mm.
  • Adequate organ and bone marrow function
  • If a woman of (WOCBP), must have a negative pregnancy test prior to starting treatment and agree to use a highly effective method of
  • Participants must have given written consent

Exclusion criteria

Exclusion Criteria:

  • If a female, the subject is pregnant or breast feeding.
  • Medical conditions, including auto-immune, requiring systemic . Any systemic treatment for these conditions (eg, ) is not allowed within 4 weeks of Screening and during the study.
  • Known TGCT or other active cancer that requires concurrent or planned treatment
  • Received systemic therapy for TGCT ( 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 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 (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.
Terms in these criteria, in plain language(10)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Biopsy and archival tissue

A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.

Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.

Measurable disease

The amount of disease can be tracked with a defined measurement, so the study can see whether it shrinks or grows. It might be a tumour measured on a scan or, in some blood cancers such as myeloma, a marker measured in blood or urine.

The criteria or the study team say which measurement counts — having no tumour visible on a scan does not by itself rule you out.

Childbearing potential

Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).

Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.

Contraception

Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.

Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.

Immunosuppression

A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.

Read whether the line is about a condition or about medicines, and which medicines and doses it means.

Corticosteroids (steroids)

Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.

Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.

Metastases

Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.

Investigational drug or device

A drug or device being studied in a clinical trial.

It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.

Clinically significant

Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.

NYHA class (heart failure)

The New York Heart Association’s four classes of how much heart failure limits physical activity.

I
No limits: ordinary activity causes no undue tiredness or breathlessness.
II
Slight limits: comfortable at rest, ordinary activity causes symptoms.
III
Marked limits: comfortable at rest, less than ordinary activity causes symptoms.
IV
Symptoms even at rest; any activity makes them worse.

Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.

05

Study design

Phase
Phase 3
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Quadruple (Participant, Care provider, Investigator, Outcomes assessor)
Enrollment
128 participants (estimated)

Study arms

  • Experimental
    Group 1 in Part 1/Part 2: Emactuzumab

    Group 1: Subjects receiving emactuzumab administered intravenously (i.v) on Day(D)1 and repeated once every two weeks (Q2W) for a total of 5 times, followed by an observation period of 3 months leading to a total period of 24 weeks in Part 1 and continued with a follow-up phase in Part 2. Eligible Subjects assigned to active drug in Part 1 have the option to receive open-label retreatment in Part 2.

    Drug: Emactuzumab

  • Placebo comparator
    Group 2 in Part 1 and Part 2: Placebo

    Group 2: Subjects receiving placebo administered intravenously (i.v) on D1 and repeated once every two weeks (Q2W) for 5 times followed by an observation period of 3 months to a total period of 24 weeks in Part 1. In Part 2, Eligible Subjects will have the option to receive open-label emactuzumab, administered by i.v once every 2 weeks (Q2W) for a total of 5 times.

    Drug: Placebo

Interventions

  • Emactuzumab administered once every 2 weeks (q2w)

  • DrugPlacebo

    Matching placebo administered once every 2 weeks (q2w)

06

What researchers measure

Primary outcomes

  1. Overall Response Rate (ORR)

    Objective Response Rate (ORR = complete response \[CR\] + partial response \[PR\]) by 6 months from initiation of therapy according to RECIST v1.1 based on independent, blinded central review

    Time frame: Day 0 - Day 180 (6 months)

Secondary outcomes

  1. Physical Function

    Change in Patient-Reported Outcomes Measurement Information System Physical Function (PROMIS-PF) TGCT from baseline to 6 months

    Time frame: up to 24 months

  2. Range of Motion (ROM)

    Mean change from baseline in active ROM of the joint over time

    Time frame: up to 24 months

  3. Worst Stiffness

    Mean change from baseline in the Worst Stiffness Numeric Rating Scale (NRS) score over time

    Time frame: up to 24 months

  4. Worst Pain

    Mean change in Pain Numerical Rating Scale (NRS) from baseline over time

    Time frame: up to 24 months

  5. Quality of Life (QoL)

    Change in EuroQol 5-dimension, 5-level questionnaire (EQ-5D-5L)

    Time frame: up to 24 months

  6. Duration of response (DoR)

    Duration of response (DoR) as measured by RECIST version 1.1

    Time frame: up to 24 months

  7. Tumour volume score (TVS)

    Change in Tumour volume score (TVS)

    Time frame: up to 24 months

  8. Surgical Intervention Rate

    The number of subjects who undergo surgery during the study for TGCT

    Time frame: up to 24 months

07

Study locations

33 sites
08

References and documents

Publications

  • Gelderblom H, Palmerini E, van de Sande M, Martin-Broto J, Tinoco G, Seltzer E, Davies M, Coll R, Veltkamp S, Blay JY. TANGENT study design: a phase III, randomized study of emactuzumab for the treatment of tenosynovial giant cell tumors. Future Oncol. 2026 Jul 20:1-11. doi: 10.1080/14796694.2026.2702768. Online ahead of print. PubMed 42473802 ↗

Individual participant data

Plan to share: No — Summary (synopsis) of the CSR

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Jul 29, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT05417789
Lead sponsor
SynOx Therapeutics Limited
Responsible party
Sponsor
First posted
Jun 14, 2022
Start date
Oct 9, 2024
Primary completion
Dec 23, 2025
Completion
Sep 30, 2030 (estimated)
Last update
Jul 29, 2026

Study contacts

Jean Y Blay, Prof, MD
principal investigator · Comprehensive Cancer Centre of Lyon

Oversight

Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is active, not recruiting, as verified in Jul 2026. You cannot join it, but the record below documents what was studied.

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Discussion

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Studies of the drug tested here: Emactuzumab

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