Study of Emactuzumab for Tenosynovial Giant Cell Tumor (TGCT)

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.