Pilot Study of Vigil™ + Pembrolizumab for Advanced Melanoma

This is an open label Pilot study to evaluate the combination of Vigil™ autologous tumor cell immunotherapy and pembrolizumab PD-1 inhibitor in patients with incurable locally advanced or metastatic melanoma. Patients undergoing a standard of care surgical procedure (e.g., tumor biopsy, palliative resection) and meeting procurement eligibility criteria may have tumor harvested for Vigil™ vaccine manufacture. Patients subsequently meeting study enrollment criteria including manufacture of a minimum of 4 doses of Vigil™ and agreement to provide on treatment tumor biopsies will receive (i) Vigil™ 1 x 10e7 cells intradermal on Days 1, 15, 29, 43 and every 3 weeks thereafter for up to 9 total doses of Vigil™ and (ii) pembrolizumab 2 mg/kg IV starting on Day 43 and every 3 weeks thereafter for up to 6 months from study enrollment. Day 1 of study treatment must be within 6 weeks of tumor procurement. Tumor biopsy and peripheral blood mononuclear cells (PBMCs) for correlative studies will be obtained at baseline (before tumor procurement), and at Week 7 and Week 16 while on study. PBMCs will also be collected at Week 1 (pre-Vigil™) and end of treatment (EOT). Radiological assessment of tumor by immune related Response Criteria (irRC) and RECIST criteria will be obtained at screening (after tumor procurement) and at Week 13 and EOT. The primary study objective is to characterize and compare CD8+ T cell density, PD-1+ T cell density, and PD-L1 expression on tumor biopsy at baseline, following 3 doses (approximately 6 weeks) of single agent Vigil™ and again following 3 doses of pembrolizumab. Secondary study objectives include evaluation of tolerability and safety of the combination, and to determine and compare IFNγ-ELISPOT result pre-procurement, at screening, after single agent Vigil™, and after Vigil™ plus pembrolizumab combination. Additional study objectives include determining best ORR by irRC criteria.