E6201 Plus Dabrafenib for the Treatment of Metastatic Melanoma Central Nervous System Metastases (CNS)

Selected subjects will be: both males and females age ≥18 years; histologically confirmed melanoma with BRAF V600 mutation with CNS metastasis; archived tumor sample from the primary, recurrent or metastatic disease with documented BRAF mutation; recovered from all acute toxicities (≤ Grade 1) due to prior immunotherapy; determined to have adequate renal and hepatic function, and no known history of significant cardiac disease. Monotherapy Safety Run-in Phase: Following screening, a total of up to 4 subjects were enrolled. E6201 was administered by intravenous (IV) infusion over a 2-hour period at a dose of 320 mg/m\^2 twice weekly (Days 1, 4, 8, 11, 15 and 18) for three weeks, repeated every 28 days (1 cycle) until progression of disease, observation of unacceptable adverse events, intercurrent illness or changes in the subject's condition that prevents further study participation. Combination Safety Run-in Phase: Following screening, a total of 6-12 subjects are anticipated to establish the recommended doses of E6201 plus dabrafenib. E6201 will be administered by IV infusion over a 2-hour period twice weekly (Days 1, 4, 8, 11, 15 and 18) repeated every 28 days plus dabrafenib orally twice daily (=1 cycle). Dose Level 1: E6201 320 mg/m\^2 twice weekly plus dabrafenib 150 mg BID. Dose Level -1: E6201 240 mg/m\^2 twice weekly plus dabrafenib 150 mg BID. Dose Level -2: E6201 240 mg/m\^2 twice weekly plus dabrafenib 100 mg BID. Dose Level -3: E6201 160 mg/m\^2 twice weekly plus dabrafenib 100 mg BID Dose Level -4: E6201 160 mg/m\^2 twice weekly plus dabrafenib 75 mg BID. Dose Level -5: E6201 160 mg/m\^2 twice weekly plus dabrafenib 50 mg BID. A total of 6 subjects will be treated at the combined MTD doses for both drugs in the Combination Safety Run-in Phase before beginning the Expansion Phase. Expansion Phase: An additional cohort of up to N=18 subjects will be treated at the E6201 plus dabrafenib combined MTD. Subjects treated at the MTD in the Combination Safety Run-in Phase will count towards accrual in the Expansion Phase. CNS disease response will be assessed according to 2 methodologies: Response Evaluation Criteria in Solid Tumors (RECIST v. 1.1) and Response Assessment in Neuro-Oncology - Brain Metastases (RANO-BM). Non-CNS systemic disease will be assessed according to RECIST v. 1.1. Blood for hematology and serum chemistry determinations will be collected and ECGs will be taken during the study. Assessments will be obtained at Week 8 and every 8 weeks thereafter until documented progression of disease (PD). Subjects who demonstrate clinical benefit will be allowed to continue therapy with E6201 until progression of disease, observation of unacceptable adverse events, intercurrent illness or changes in the subject's condition that prevents further study participation.