Study of Emactuzumab for Tenosynovial Giant Cell Tumor (TGCT)

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.