Study of HBI-8000 With Nivolumab in Melanoma, Renal Cell Carcinoma and Non-Small Cell Lung Cancer

A Phase 1b/2 Study to Assess the Safety and Efficacy of HBI-8000 in Combination with Nivolumab in Patients with Advanced Solid Tumors Including Melanoma, Renal Cell Carcinoma (RCC), and Non-Small Cell Lung Cancer (NSCLC). The primary objective of this study is: -To evaluate the safety and tolerability of HBI-8000 when combined with a standard dose and regimen of nivolumab, and to evaluate frequency and severity of toxicities of this combination treatment The secondary objectives of this study include: * To explore the efficacy of study treatment as measured by Objective Response Rate (ORR), Disease Control Rate (DCR), Clinical Benefit Rate (CBR), Duration of Response (DoR), Progression-Free Survival (PFS) in all subjects treated at RP2D * To obtain pharmacokinetics of twice weekly HBI-8000 when administered in combination with nivolumab administered once every two weeks (Phase 1b all sites) * To obtain pharmacokinetics of twice weekly HBI-8000 when administered in combination with nivolumab administered per package insert dose and administration (Phase 2 selected sites) * To characterize the effect of HBI-8000 on the electrocardiogram QT corrected (QTc) interval (Phase 1b only) Exploratory: * To investigate the kinetics and extent of histone acetylation in peripheral blood mononuclear cells (PBMC) at the RP2D of HBI-8000 (Phase 2 only) * To explore potential biomarkers for disease response through sequential sampling of blood and/or tumor tissue in subjects consenting to correlative sub-studies at participating sites (Phase 2 only) Dose Escalation (Phase 1b) will include up to 18 subjects, followed by Cohort Expansion (Phase 2) including up to 100 subjects (melanoma up to 60 subjects and NSCLC up to 40 subjects at MTD and/or RP2D.