Study of Cabiralizumab in Patients With Pigmented Villonodular Synovitis / Diffuse Type Tenosynovial Giant Cell Tumor

Inclusion Criteria:

   - Histologically confirmed diagnosis of inoperable PVNS/ dt-TGCT or potentially
   resectable tumor that would result in unacceptable functional loss or morbidity as
   determined by a qualified surgeon or multi-disciplinary tumor board (must be
   documented in the CRF during screening)

   - Measurable PVNS/dt-TGCT by RECIST 1.1 on MRI

   - ECOG performance status <1

Exclusion Criteria:

   - Prior therapy with an anti-CSF1R antibody

   - Prior therapy with PLX3397 unless discontinued for intolerance (i.e., non-progression
   on prior kinase inhibitor)

   - Liver function tests (including ALT, AST, and total bilirubin), outside of the range
   of local laboratory normal at Screening

   - Inadequate organ or bone marrow function

   - History of congestive heart failure or myocardial infarction <1 year prior to first
   study dose administration

   - Significant abnormalities on ECG at Screening

   - Contraindications to MRI and use of intravenous gadolinium-based contrast agents

   - Creatine Kinase ≥ 1.5x the upper limit of normal

   - Positive test for latent TB at Screening (Quantiferon test)

   - Active known or suspected autoimmune disease