Testing the Addition of Navitoclax to the Combination of Dabrafenib and Trametinib in People Who Have BRAF Mutant Melanoma

PRIMARY OBJECTIVES: I. To determine the maximum tolerated dose (MTD), toxicity, and safety profile of navitoclax when given in combination with dabrafenib and trametinib in patients with BRAF-mutant solid tumors. (Phase I) II. To estimate the complete response (CR) rate in patients with BRAF-mutant melanoma treated with dabrafenib, trametinib, and navitoclax as compared to the historical control dabrafenib and trametinib combination (DT). (Phase II) III. To compare the maximal tumor regression in patients with BRAF-mutant melanoma treated with dabrafenib, trametinib versus dabrafenib, trametinib, and navitoclax. (Phase II) SECONDARY OBJECTIVES: I. To describe pharmacodynamics effects of treatment with dabrafenib, trametinib, and navitoclax on both serial tumor biopsies and serial blood draws in a small subset of patients treated with BRAF-mutant melanoma. (Phase I) II. To describe the pharmacokinetics of treatment with dabrafenib, trametinib, and navitoclax. (Phase I) III. To compare the progression-free survival (PFS), overall survival (OS), and overall response rate (ORR) in patients with BRAF-mutant melanoma treated with dabrafenib, trametinib, versus dabrafenib, trametinib, and navitoclax. (Phase II) IV. To compare the degree of apoptosis induced in on-treatment biopsies of patients with BRAF-mutant melanoma treated with dabrafenib, trametinib versus dabrafenib, trametinib, and navitoclax. (Phase II) V. To explore other pharmacodynamic effects in on-treatment biopsies of patients with BRAF-mutant melanoma treated with either dabrafenib, trametinib versus dabrafenib, trametinib, and navitoclax including cell proliferation (Ki-67), proteomics (reverse-phase protein microarrays \[RPPA\]), and B-cell chronic lymphocytic leukemia (CLL)/lymphoma 2 (BCL-2) family gene expression analysis. (Phase II) OUTLINE: This is a phase I, dose-escalation study of dabrafenib, trametinib, and navitoclax followed by a randomized phase II study. PHASE I: Patients receive navitoclax orally (PO) once daily (QD) on days -7 to -1 of cycle 1 only. Patients also receive dabrafenib PO twice daily (BID), trametinib PO QD, and navitoclax PO QD days 1-28. Cycles repeat every 28 days in the absence of disease progression or unacceptable toxicity. Patients also undergo electrocardiography (ECHO) or multigated acquisition scan (MUGA), magnetic resonance imaging (MRI) or computed tomography (CT), also undergo biopsy, and collection of blood samples throughout the trial. PHASE II: Patients are randomized to 1 of 2 arms. ARM I: Patients receive dabrafenib PO BID and trametinib PO QD on days 1-28. Cycles repeat every 28 days in the absence of disease progression or unacceptable toxicity. Patients also undergo ECHO or MUGA, MRI or CT, biopsy, and collection of blood samples throughout the trial. ARM II: Patients receive navitoclax PO QD days -7 to -1 of cycle 1 only. Patients also receive dabrafenib PO BID, trametinib PO QD, and navitoclax PO QD on days 1-28. Cycles repeat every 28 days in the absence of disease progression or unacceptable toxicity. Patients also undergo ECHO or MUGA, MRI or CT, biopsy, and collection of blood samples throughout the trial. After the completion of study treatment, patients are followed up for clinical evaluation at 28 days and every 3 months thereafter until disease progression or death, whichever comes first. For survival follow up, patients are followed every 12 months for 3 years.