A Study of PRT3789 in Combination With Pembrolizumab in Patients With Advanced or Metastatic Solid Tumors With a SMARCA4 Mutation

Phase 2TerminatedNCT06682806

Prelude Therapeutics6 enrolled

Overview

This is a Phase 2 an open-label, multi-center study to determine the safety, tolerability, efficacy, pharmacokinetics, pharmacodynamics, and anti-tumor activity of PRT3789 in combination with pembrolizumab in patients with advanced, recurrent or metastatic solid tumors with a SMARCA4 mutation.

This is an open-label, multi-center Phase 2 study of PRT 3789, a first-in-class SMARCA2 targeted protein degrader, in combination with pembrolizumab, a potent humanized immunoglobulin G4 (IgG4) monoclonal antibody (mAb) with high specificity of binding to the programmed cell death 1 (PD-1) receptor, evaluating patients with Advanced or Metastatic Solid Tumors with a SMARCA4 Mutation. This study consists of 2 parts. Part 1 is a safety run-in and will establish the dose of PRT3789 to be used in combination with pembrolizumab in the main study (Part 2). For Part 2 (Main study) primary endpoints are ORR (defined as the proportion of patients with a confirmed best overall response of either complete response or partial response) and duration of response per investigator assessment per RECIST v1.1. Approximately 46 to 60 patients will be enrolled in Part 1 and Part 2 based on the dose of PRT3789 selected/cleared during the safety run-in.

Study Type

INTERVENTIONAL

Allocation

Purpose

TREATMENT

Masking

NONE

Enrollment

Conditions

Advanced Solid Tumor Esophageal Cancer

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Patients who are willing and able to comply with all scheduled visits, treatment plan, laboratory tests, lifestyle considerations and other study procedures, including providing informed consent. * Patients must either progress on standard of care therapy or be ineligible for standard of care therapy in order to be eligible for enrollment on the study. * Part 1 Safety Run-in: Patients with advanced, recurrent, or metastatic histologically or cytologically confirmed solid tumor malignancy and any mutation of SMARCA4 detected by next generation sequencing in tumor tissue or blood, or absence of SMARCA4 protein (BRG1). Part 2 Main Study: Patients with advanced, recurrent, or metastatic histologically confirmed esophageal cancer or NSCLC and have a deleterious SMARCA4 mutation, or absence of SMARCA4 protein (BRG1) detected by immunohistochemistry in tumor tissue using a clinically validated laboratory test. * Part 1 Run-in: Measurable or non-measurable (but evaluable) disease per RECIST v1.1 as assessed by the local site investigator/radiologist. Part 2 Main Study: Measurable disease per RECIST v1.1 as assessed by the local site investigator/radiologist. Lesions situated in a previously irradiated area are considered measurable if progression has been shown in such lesions. * Willingness and ability to provide tumor tissue (i.e., archived or fresh tumor biopsy if archived tumor tissue is unavailable) * Adequately controlled blood pressure with or without antihypertensive medications. * Patients with HIV must have well-controlled HIV on antiretroviral therapy. * Adequate organ function Exclusion Criteria: * Patients who have adverse events due to previous anticancer therapies and/or complications from prior surgical intervention must have recovered to ≤ Grade 1 or baseline before starting study treatment. Patients with endocrine-related AEs who are adequately treated with hormone replacement or patients who have ≤ Grade 2 neuropathy are eligible. * Other acute or chronic medical or psychiatric conditions that would make the patient inappropriate for entry into this study. * Patients with solid tumors with a known concomitant SMARCA2 mutation or loss of protein expression. * Uncontrolled or symptomatic central nervous system (CNS) metastases or leptomeningeal disease and/or carcinomatous meningitis). * History of or current (noninfectious) pneumonitis/interstitial lung disease * Diagnosis of immunodeficiency disease/disorder. * Known additional malignancy that is progressing or has required active treatment within the past 3 years. * Patients who received prior treatment with an agent directed to a stimulatory or co-inhibitory T-cell receptor. * Currently taking a strong or moderate CYP3A4 inhibitor or inducer and St. John's Wort and are unable to discontinue use within 15 days of the first dose of study treatment. * Receipt of any targeted therapy directed against BRM/BRG1 (SMARCA2/SMARCA4). * Pregnant or breastfeeding or plan to become pregnant during the duration of the study.

Locations (9)

Florida Cancer Specialists

West Palm Beach, Florida, United States

Karmanos Cancer Institute

Detroit, Michigan, United States

John Theurer Cancer Center at Hackensack University Medical Center

Hackensack, New Jersey, United States

SCRI Oncology Partners

Nashville, Tennessee, United States

Tennessee Oncology, PLLC - Greco-Hainsworth Centers for Research

Nashville, Tennessee, United States

The University of Texas MD Anderson Cancer Center

Houston, Texas, United States

IOB - Next Oncology - Hospital Quironsalud Barcelona

Barcelona, Spain

START Barcelona - HM Nou Delfos

Barcelona, Spain

Hospital Universitario Fundacion Jimenez Diaz - Servicio de Oncologia

Madrid, Spain

Outcomes

Primary Outcomes

Safety and tolerability of PRT3789 in combination with pembrolizumab as measured by incidence of DLTs (Part 1)

Safety and tolerability will be evaluated by incidence of dose-limiting toxicities (DLTs)

Time frame: Baseline through completion of study, an average of 2 years

Safety and tolerability of PRT3789 in combination with pembrolizumab as measured by incidence and severity of AEs according to NCI CTCAE (Part 1)

Safety and tolerability will be evaluated by incidence and severity of adverse events (AEs) according to National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE)