Primary analysis of TANGENT: A phase 3 randomised trial evaluating the safety and efficacy of emactuzumab in patients with tenosynovial giant cell tumours

TANGENT

Patient / Population Intervention / Exposure Comparison Outcome

In patients with tenosynovial giant cell tumours, short-course emactuzumab improved overall response rate by RECIST v1.1 at 6 months compared with placebo.

N

136patients

Design

Global phase 3, randomised 2:1, double-blind, placebo-controlled trial of short-course intravenous emactuzumab vs placebo in patients with tenosynovial giant cell tumours (NCT05417789).

Endpoint

Overall response rate by RECIST v1.1 at 6 months.

ResultORR by RECIST v1.1 at 6 months 29.7% with emactuzumab vs 2.2% with placebo, difference 27.8 (95% CI 16.2-38.5; P<0.001). ORR by tumour volume score 53.8% vs 6.7%, difference 47.8 (95% CI 33.7-59.4; P<0.001). LS mean change from baseline in PROMIS-PF 4.3 vs -1.3, difference 5.6 (95% CI 3.3-7.9; P<0.001). Passive ROM 9.93 vs 2.12, difference 7.81 (95% CI 3.17-12.45; P<0.001). Worst stiffness -2.4 vs -0.3, difference -2.1 (95% CI -3.0 to -1.3; P<0.001). Worst pain -2.5 vs -0.4, difference -2.2 (95% CI -3.0 to -1.4; P<0.001). EQ-5D-5L VAS 2.0 vs -0.4, difference 2.4 (95% CI -4.2 to 9.1; P=0.238). Safety was consistent with phase 1 data and CSF-1R inhibitors.

Gelderblom H, Palmerini E, Van de Sande M, et al. Presented at ESMO Congress 2026, abstract LBA89, 24 October. Not yet published.

Discussion & critique

This double-blind, placebo-controlled trial shows that a short course of emactuzumab shrinks tumours and improves function, pain and stiffness at 6 months, although the EQ-5D-5L VAS did not differ from placebo. The primary endpoint is radiographic response at a single 6-month time point, and the abstract does not report how durable responses are after treatment stops or whether tumours regrow. Safety is described only as consistent with earlier data, with no adverse event rates or discontinuations given, and the abstract gives no details on tumour subtype or prior treatment. The comparator is placebo, not an existing CSF-1R inhibitor, and the trial was funded by SynOx Therapeutics Ltd.