SynOx Therapeutics has completed subject enrolment in its multi-centre Phase III TANGENT trial of the humanised IgG1 monoclonal antibody (mAb) emactuzumab for the treatment of tenosynovial giant cell tumours (TGCTs).

The global, double-blind, placebo-controlled, randomised trial aims to evaluate the efficacy and safety of emactuzumab in those who are unsuitable for surgical intervention or unlikely to derive benefit from it.

The primary goal of the trial is the objective response rate (ORR) as per the RECIST criteria evaluations at six months after randomisation.

Subjects are randomised into a 2:1 ratio to be given either emactuzumab or a matched placebo, with the treatment comprising 1,000mg of the therapy given every two weeks for five doses.

Secondary goals of the study include outcomes reported by patients, functional evaluations of the range of motion, stiffness, pain, safety, and durability of response. Participants will be followed for two years following randomisation, with those showing disease progression post six months eligible for open-label emactuzumab.

SynOx anticipates reporting top-line data from the TANGENT trial in the first quarter of 2026.

SynOx Therapeutics chief medical officer Elyse Seltzer said: “Completion of enrolment in our registrational TANGENT trial marks an important milestone for SynOx and for the TGCT community.

“We are deeply grateful to the patients, families, investigators, and clinical sites whose dedication has made this study possible and allowed SynOx to fully enrol the trial significantly ahead of our projected timeline.”

Developed originally by Roche, emactuzumab is said to target CSF-1 receptors (CSF-1R).

In earlier trials, the therapy demonstrated an objective response rate of approximately 71%, rapid tumour minimisation, and a manageable safety profile.

TGCT is formerly known as pigmented villonodular synovitis and is an uncommon, non-malignant tumour that can lead to loss of function, pain, and stiffness in the affected joints.

Earlier this year, the US Food and Drug Administration (FDA) granted fast-track designation to the therapy for TGCT treatment while the European Medicines Agency awarded it an orphan medicinal product designation.

The company is also exploring further development opportunities for emactuzumab in other macrophage-driven diseases.