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A Phase 2 Study of PRT3789 in Combination with Pembrolizumab in Patients with Advanced or Metastatic Solid Tumors with a SMARCA4 Mutation

Phase 2
Recruiting
Conditions
Esophageal Cancer
Advanced or Metastatic Solid Tumors with a SMARCA4 Mutation
non-small cell lung cancer (NSCLC)
Interventions
Registration Number
2024-516889-11-00
Lead Sponsor
Prelude Therapeutics Inc.
Brief Summary

To evaluate the safety and tolerability of PRT3789 in combination with pembrolizumab in patients with advanced or metastatic solid tumors and to evaluate the efficacy of PRT3789 in combination with pembrolizumab in patients with advanced or metastatic esophageal or NSCLC and deleterious SMARCA4 mutation

Detailed Description

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.

Recruitment & Eligibility

Status
Authorised, recruiting
Sex
Not specified
Target Recruitment
20
Inclusion Criteria

Patients age ≥ 18 at the time of informed consent

Adequate organ function (hematology, renal, hepatic, coagulation)

Patients who are willing and able to comply with all scheduled visits, treatment plan, laboratory tests, lifestyle considerations (including contraception requirements), and other study procedures, including providing informed consent.

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 (loss of function) SMARCA4 mutation

Patients must have at least one of the following: a. Primary resistance to prior anti-PD-1/PD-L1, defined by disease that did not respond at all and instead progressed on anti-PD-L1 therapy (e.g., best response of progressive disease per RECIST 1.1). b. Acquired resistance to prior anti-PD-1/PD-L1, defined as: (i) patients who received anti-PD-1/PD-L1 therapy, (ii) had a partial or complete response, and (iii) progressed within 6 months of prior anti-PD-1/PD-L1 therapy. c. Received prior standard of care therapy but did not receive prior anti-PD-1/PD-L1 therapy because tumor PD-L1 expression was negative. d. Prior anti-PD-1/PD-L1 therapy discontinued for reasons other than disease progression, and subsequent progression > 6 months from prior anti-PD-1/PD-L1.

Part 1 Safety 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

Eastern Cooperative Oncology Group performance status of 0 or 1.

Willingness and ability to provide tumor tissue (i.e., archived or fresh if archived tumor tissue is unavailable).

Adequately controlled blood pressure with or without antihypertensive medications, defined as blood pressure < 160/100 mmHg at screening and no change in antihypertensive medications within 1 week before Cyle 1 Day 1.

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. Note: Stable chronic conditions (≤ Grade 2) that are not expected to resolve (e.g., neuropathy, myalgia, alopecia and prior therapy-related endocrinopathies) are exceptions.

Receipt of any of the following within the specified time intervals before first dose of study treatment, unless otherwise specified or with approval by the Sponsor medical monitor: o Live or live-attenuated vaccine within 30 days o Chemotherapy or chemoimmunotherapy within 21 days or 5 half-lives, whichever is shorter. o Radiotherapy within 14 days. o Radiation therapy to the lung that is > 30 Gy within 6 months o Major surgery within 14 days.

Currently participating in an interventional study of an investigational agent.

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 (e.g., small-cell carcinoma of the ovary hypercalcemic type or thoracic sarcomatoid tumors).

Uncontrolled or symptomatic (e.g., clinical symptoms, cerebral edema) central nervous system metastases or leptomeningeal disease and/or carcinomatous meningitis).

Currently taking a strong or moderate Cytochrome P450 (CYP)3A4 inhibitor or inducer and St. John’s Wort and are unable to discontinue use within 15 days of the first dose of study treatment.

Known additional malignancy that is progressing or has required active treatment within the past 3 years. Note: Participants with basal cell carcinoma of the skin, squamous cell carcinoma of the skin, or carcinoma in situ, excluding carcinoma in situ of the bladder, who have undergone potentially curative therapy are not excluded.

Patients with clinically significant or uncontrolled cardiac disease, uncontrolled electrolyte disorders, patients with an active infection requiring hospitalization or systemic therapy, HIV patients with Kaposi Sarcoma or Multicentric Castleman Disease, known history of hepatitis B or active hepatitis C.

Pregnant or breastfeeding or plan to become pregnant during the study.

Severe hypersensitivity (≥ Grade 3) to pembrolizumab or contraindication to any excipients of study treatment (PRT3789 or pembrolizumab)

Study & Design

Study Type
INTERVENTIONAL
Study Design
SEQUENTIAL
Arm && Interventions
GroupInterventionDescription
PRT3789/Pembrolizumab combinationpembrolizumabPRT3789 is administered as an intravenous infusion once weekly for 3 weeks; Pembrolizumab is administered at 200 mg as an intravenous infusion over 30 min every 3 weeks
PRT3789/Pembrolizumab combinationPRT3789PRT3789 is administered as an intravenous infusion once weekly for 3 weeks; Pembrolizumab is administered at 200 mg as an intravenous infusion over 30 min every 3 weeks
Primary Outcome Measures
NameTimeMethod
Incidence of dose-limiting toxicities

Incidence of dose-limiting toxicities

Incidence and severity of adverse events according to the NCI CTCAE v5.0

Incidence and severity of adverse events according to the NCI CTCAE v5.0

Objective response rate defined as the proportion of patients with a confirmed best overall response of either complete response or partial response, as determined per investigator assessment by RECIST v1.1

Objective response rate defined as the proportion of patients with a confirmed best overall response of either complete response or partial response, as determined per investigator assessment by RECIST v1.1

Duration of response defined as the time from the date of the first documented response (complete response or partial response) to the earliest date of disease progression, as determined per investigator assessment by RECIST v1.1, or death due to any cause

Duration of response defined as the time from the date of the first documented response (complete response or partial response) to the earliest date of disease progression, as determined per investigator assessment by RECIST v1.1, or death due to any cause

Secondary Outcome Measures
NameTimeMethod
Objective response rate defined as the proportion of patients with a best overall response of either complete response or partial response, as determined per investigator assessment by RECIST v1.1 (Part 1 only)

Objective response rate defined as the proportion of patients with a best overall response of either complete response or partial response, as determined per investigator assessment by RECIST v1.1 (Part 1 only)

Duration of response defined as the time from the date of the first documented response (complete response or partial response) to the earliest date of disease progression, as determined per investigator assessment by RECIST v1.1, or death due to any cause (Part 1 only)

Duration of response defined as the time from the date of the first documented response (complete response or partial response) to the earliest date of disease progression, as determined per investigator assessment by RECIST v1.1, or death due to any cause (Part 1 only)

Clinical benefit response defined as the proportion of patients with a best overall response of complete response, partial response, or durable stable disease (24 weeks or longer), as determined per investigator assessment by RECIST v1.1

Clinical benefit response defined as the proportion of patients with a best overall response of complete response, partial response, or durable stable disease (24 weeks or longer), as determined per investigator assessment by RECIST v1.1

PFS defined as the time from the date of first dose of study treatment to the date of first documented progressive disease, as determined per investigator assessment by RECIST v1.1, or death due to any cause

PFS defined as the time from the date of first dose of study treatment to the date of first documented progressive disease, as determined per investigator assessment by RECIST v1.1, or death due to any cause

Overall survival defined as the time from the date of first dose of study treatment to death due to any cause

Overall survival defined as the time from the date of first dose of study treatment to death due to any cause

Incidence and severity of adverse events according to the NCI CTCAE v5.0

Incidence and severity of adverse events according to the NCI CTCAE v5.0

Changes in clinical laboratory parameters

Changes in clinical laboratory parameters

Incidence of dose interruptions, dose modifications, and discontinuations due to adverse events

Incidence of dose interruptions, dose modifications, and discontinuations due to adverse events

The pharmacokinetics of PRT3789 in combination with pembrolizumab including the maximum observed plasma concentration, time of maximum concentration, AUC, steady state trough concentrations, clearance, accumulation, and half-life

The pharmacokinetics of PRT3789 in combination with pembrolizumab including the maximum observed plasma concentration, time of maximum concentration, AUC, steady state trough concentrations, clearance, accumulation, and half-life

Trial Locations

Locations (5)

Goethe University Frankfurt

🇩🇪

Frankfurt Am Main, Germany

Hospital Universitario Fundacion Jimenez Diaz

🇪🇸

Madrid, Spain

Hospital Quironsalud Barcelona

🇪🇸

Barcelona, Spain

Hospital Hm Nou Delfos

🇪🇸

Barcelona, Spain

Institut Gustave Roussy

🇫🇷

Villejuif, France

Goethe University Frankfurt
🇩🇪Frankfurt Am Main, Germany
Fabian Acker
Site contact
496963016217
acker@med.uni-frankfurt.de
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