An Exploratory Study of Pembrolizumab Plus Entinostat in Non-Inflamed Stage III/IV Melanoma

Melanoma Clinical Trial

Official title: Breaking Innate PD-1 Inhibitor (PD1i) Resistance Using Epigenetic Modifiers; Antitumor Efficacy and Correlative Analyses of Entinostat Plus Pembrolizumab in Non-Inflamed Metastatic Melanoma (MM)

Status Completed

Clinical Trial Summary

Cancers develop in two different ways. First, cancer cells can become invisible to the immune system by stop having proteins on their surface that are required for the immune system to recognize them. In this scenario, tumors do not attract any immune cells (e.g. white blood cells) whatsoever or they do not attract specialized white blood cells against cancer cells, called lymphocytes. White blood cells are the type of immune cells that attack foreign cells, such as cancer cells or normal cells infected with viruses or bacteria. Second, cancer cells can still grow side-to-side with white blood cells but are able to hide from them. As a result, the white blood cells cannot find and attack the cancer cells. Different types of cancers have different chance of having immune cells in the tumor. For example, the possibility that immune cells are within skin melanomas is almost 50% whereas the possibility in melanoma of the eye is only 10%.

As a result, the first goal of this study is to understand whether entinostat can make a melanoma tumor more visible to the immune system. To see whether entinostat makes tumor more visible to the immune system, participants will have a mandatory tumor biopsy 3 weeks after starting entinostat therapy. Tumor tissue collected before and after participating in this study will be compared to see if there are more immune cells in the tumor after receive entinostat. The second goal of the study is to see if giving a combination of entinostat and pembrolizumab can shrink melanoma tumors of patients who did not have immune cells in tumors prior to treatment. The study will determine how many subjects cancer has become better or not changed 6 months after subjects have started treatment on the study. We will also determine what type of side effects occur in subjects receiving entinostat and pembrolizumab to look at the safety of this combination.

The investigators will also look at any changes in the DNA of melanoma before the study begins. As a result of these changes in DNA, there are often see differences in the proteins that work to create other proteins. In addition, the study will look into how entinostat may make melanoma cells more visible to the immune system by comparing proteins in tumors before and after treatment. Finally, the study will see if this treatment changes the numbers and types of immune cells that are found in the blood by comparing blood at different time points while patients are on the study.

Clinical Trial Description

This is an exploratory (n=10-12 evaluable patients), open-label, single-arm, phase II study in patients with 'non-inflamed' unresectable regional or distant metastatic melanomas irrespective of prior treatment with PD-1/PD-L1 pathway inhibitors. The primary endpoint is to assess the incidence of histopathologic conversion of non-inflamed melanomas from patients with metastatic melanoma to 'inflamed' melanoma following single-agent entinostat "priming" (entinostat monotherapy). More specifically, patients with metastatic melanomas that have no evidence of tumor-infiltrating or tumor-associated lymphocytes (TIL/TAL), based on standard hematoxylin and eosin (H&E) staining of representative tumor sections (non-inflamed melanomas) will receive weekly entinostat for 3 weeks in cycle 1 (entinostat monotherapy; 5mg PO, qwk on D1, D8, D15 of cycle 1; cycle length = 21 days). Mandatory tumor tissue biopsies will be performed in the end of cycle 1, beginning of cycle 2 (day 21±2 days), immediately before treatment with concurrent entinostat (once weekly × 3) and pembrolizumab (200 mg q3wks) in cycles 2-9 (see section 5.2.1 drug dosing schema). Correlative studies will be performed at baseline and in the end of cycle 1, beginning of cycle 2 (day 21±2 days) to assess whether: (a) 3 weeks of entinostat monotherapy converts TIL/TAL-absent melanomas to TIL/TAL-present by histopathologic (H&E stain) analysis, (b) 3 weeks of single-agent entinostat induces changes in gene expression profiling by assessing distinct signatures as defined by RNA-sequencing signatures (RNA-seq; 'immune-high', innate anti-PD-1 resistance, and epigenetic 1-3), (c) 3 weeks of single-agent entinostat induces changes in histone-accessible DNA by performing formaldehyde-assisted isolation of regulatory elements (FAIRE)4, (d) conversion of non-inflamed to inflamed melanomas by single-agent entinostat and/or antitumor response to the entinostat-pembrolizumab combination is associated with a baseline signature that consists of distinct somatic mutation gene profile, global histone modification profile in melanoma tissue or peripheral blood mononuclear cells (PBMC), and/or abundance of entinostat targets in melanoma cells (HDAC 1, 2, 3, and 11). Up to 12 evaluable patients will be treated with entinostat plus pembrolizumab for up to 27 weeks (approximately 6 months) based on clinical benefit. Patients who continue to have clinical benefit at 27 weeks may continue therapy with pembrolizumab or any other PD-1/PD-L1 inhibitor, as per standard of care.Secondary exploratory endpoints involve: (a) assessment of antitumor response of entinostat administered concurrently with pembrolizumab at week 10 (or earlier if patient progresses), based on response rate per Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST v1.1). (b) assessment of the progression-free survival (PFS) rate at 27 weeks (approximately 6 months) of the entinostat-pembrolizumab combination. (c) determine the safety of the entinostat-pembrolizumab combination in patients with metastatic melanoma per NCI Common Terminology Criteria for Adverse Events (NCI-CTCAE). (d) assessment of other exploratory biomarkers in tumor tissue and peripheral blood. ;

Related Conditions & MeSH terms

• Melanoma

• NCT number: NCT03765229
• Study type: Interventional
• Source: UNC Lineberger Comprehensive Cancer Center
• Status: Completed
• Phase: Phase 2
• Start date: March 22, 2019
• Completion date: July 31, 2023