Study of Vimseltinib (DCC-3014) in Patients With Advanced Tumors and Tenosynovial Giant Cell Tumor

This is a multicenter, open-label Phase 1/2 study of vimseltinib in patients with malignant solid tumors and tenosynovial giant cell tumor (TGCT). There will be 2 distinct parts in this study: Dose Escalation (Phase 1) and Expansion (Phase 2). Phase 1 will enroll both malignant solid tumor and TGCT patients. Phase 2 will comprise two cohorts (Cohort A and Cohort B) and will only enroll TGCT patients.

Inclusion Criteria Dose Escalation Phase: 1. Patients ≥18 years of age 2. Patients must have: 1. advanced malignant solid tumors; or 2. symptomatic TGCT for which surgical resection is not an option (tumor biopsy to confirm diagnosis required if no histology/pathology available at screening) 3. Malignant solid tumor patients only: Able to provide a tumor tissue sample 4. Must have 1 measurable lesion according to RECIST Version 1.1 5. Malignant solid tumor patients only: Must have Eastern Cooperative Oncology Group (ECOG) performance status of 0-1 6. Adequate organ and bone marrow function 7. If a female of childbearing potential, must have a negative pregnancy test prior to enrollment and agree to follow the contraception requirements. 8. Must provide signed consent to participate in the study and is willing to comply with study-specific procedures. Expansion Phase (Cohorts A and B) 1. Patients ≥18 years of age 2. Patients must have symptomatic TGCT for which surgical resection is not an option (tumor biopsy to confirm diagnosis required if no histology/pathology available at screening) a) Expansion Cohort B: patients must have prior systemic treatment with anti-CSF1 or anti-CSF1R therapy, with the exception of imatinib or nilotinib 3. Adequate organ and bone marrow function 4. Must have at least 1 measurable lesion according to RECIST Version 1.1 5. If a female of childbearing potential, must have a negative pregnancy test prior to enrollment and agree to follow the contraception requirements. 6. Must provide signed consent to participate in the study and is willing to comply with study-specific procedures. Exclusion Criteria Dose Escalation Phase: 1. Received anticancer therapy or therapy for TGCT, including investigational therapy, within 2 weeks or 28 days for therapies with half-life (t1/2) longer than 3 days prior to the administration of study drug. 2. Unresolved toxicity (Grade \>1 or baseline) from previous anticancer therapy or TGCT therapy, excluding alopecia. 3. Known active central nervous system (CNS) metastases. 4. History or presence of clinically relevant cardiovascular abnormalities. 5. Systemic arterial or venous thrombotic or embolic events. 6. QT interval corrected by Fridericia's formula (QTcF) \>450 ms in males or \>470 ms in females or history of long QT syndrome. 7. Left ventricular ejection fraction (LVEF) \