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PRT3789 Monotherapy and in Combo w/Docetaxel in Participants w/Advanced or Metastatic Solid Tumors w/SMARCA4 Mutation

Phase 1
Recruiting
Conditions
Advanced Solid Tumor
Metastatic Solid Tumor
Non-small Cell Lung Cancers
SMARCA4 Gene Mutation
Interventions
Registration Number
NCT05639751
Lead Sponsor
Prelude Therapeutics
Brief Summary

This is a Phase 1 dose-escalation study of PRT3789, a SMARCA2 degrader, in participants with advanced or metastatic solid tumors with loss of SMARCA4 due to truncating mutation and/or deletion. The purpose of this study is to evaluate the safety, tolerability, pharmacokinetic (PK), and pharmacodynamic (PD) of PRT3789 monotherapy and in combination with docetaxel, describe any dose limiting toxicities (DLTs), define the dosing schedule, and to determine the maximum tolerated dose (MTD) and recommended phase 2 dose (RP2D) to be used in subsequent development of PRT3789.

Detailed Description

This is an open-label, multi-center, dose-escalation, first in human, Phase 1 study of PRT3789 as monotherapy and in combination with docetaxel, a SMARCA2 degrader, evaluating participants with advanced or metastatic solid tumors with loss of SMARCA4 due to truncating mutation and/or deletion. The study will evaluate escalating doses of PRT3789 until the MTD or RP2D is determined. Taking into account pharmacokinetic and pharmacodynamic data from the preceding dose levels, the dose may be escalated until a dose limiting toxicity is identified. Approximately 186 participants will be enrolled in monotherapy, dose escalation, backfill, and combination cohorts.

Recruitment & Eligibility

Status
RECRUITING
Sex
All
Target Recruitment
226
Inclusion Criteria
  • Willing and able to comply with all scheduled visits, treatment plan, laboratory tests, lifestyle considerations (including contraception requirements), and other study procedures
  • Histologically confirmed advanced, recurrent, or metastatic solid tumor malignancy with any mutation of SMARCA4 (dose escalation and combination cohorts) and loss of function mutation of SMARCA4 (backfill cohorts) by local testing that have either progress on or ineligible for standard of care therapy
  • Must have measurable or non-measureable (but evaluable) disease per RECIST v1.1 for dose escalation and combination cohorts
  • Must have measureable diseases per RECIST v1.1 for backfill cohort
  • Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 or 1
  • Willing to provide either archival or fresh tumor tissue sample
  • Adequate organ function (hematology, renal, and hepatic)
Exclusion Criteria
  • Participants with solid tumors with known concomitant SMARCA2 mutation or loss of protein expression
  • Clinically significant or uncontrolled cardiac disease, uncontrolled electrolyte disorders, uncontrolled or symptomatic central nervous system (CNS) metastases or leptomeningeal disease
  • History of another malignancy within 3 years except for adequately treated basal cell or squamous cell skin cancer, superficial bladder cancer, prostate intraepithelial neoplasm, carcinoma in situ of the cervix, or other noninvasive or indolent malignancies, or malignancies previously treated with curative intent and not on active therapy or expected to require treatment or recurrence during the study
  • Concurrent treatment with strong or moderate CYP3A4 inhibitor or inducer

Study & Design

Study Type
INTERVENTIONAL
Study Design
SEQUENTIAL
Arm && Interventions
GroupInterventionDescription
PRT3789 MonotherapyPRT3789PRT3789 will be administered by intravenous infusion
PRT3789/Docetaxel CombinationPRT3789PRT3789 and Docetaxel will be administered by intravenous infusions
PRT3789/Docetaxel CombinationDocetaxelPRT3789 and Docetaxel will be administered by intravenous infusions
Primary Outcome Measures
NameTimeMethod
Safety and tolerability of PRT3789 monotherapy and in combination with docetaxel: AEs, CTCAE AssessmentsBaseline through approximately 3 years

Safety and tolerability will be evaluated by incidence of DLTs, laboratory measurements, dose interruption, modification, and discontinuation due to adverse events (AEs) according to National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE)

Dose limiting toxicity (DLT) of PRT3789 monotherapy and in combination with docetaxelBaseline through Day 21

Dose limiting toxicities will be evaluated over the 21-day observation period

Maximum tolerated dose (MTD)/ Recommended phase 2 dose (RP2D) of PRT3789 monotherapy and in combination with docetaxelBaseline through approximately 3 years

The MTD/RP2D will be established for further investigation in participants with advanced solid tumors

Secondary Outcome Measures
NameTimeMethod
Pharmacodynamic effect of PRT3789 monotherapy and in combination with docetaxel: Target engagementBaseline through approximately 3 years

Pharmacodynamic effect of PRT3789 monotherapy and in combination with docetaxel demonstrating target engagement by assessment of SMARCA2 protein in peripheral blood mononuclear cells (PBMCs) and tumor tissue

Efficacy of PRT3789 monotherapy and in combination with docetaxel: Objective response rate (ORR)Baseline through approximately 3 years

Best overall response of either complete response (CR) or partial response (PR), as assessed by the investigator per RECIST v1.1

Efficacy of PRT3789 monotherapy and in combination with docetaxel: Duration of response (DOR)Baseline through approximately 3 years

Duration from time of first observed response (CR or PR) to the earliest date of disease progression, as assessed by the investigator per RECIST v1.1, or death due to any cause

Efficacy of PRT3789 monotherapy and in combination with docetaxel: Progression-free survival (PFS)Baseline through approximately 3 years

Duration from Day 1 to the earliest date of first disease progression, as assessed by the investigator per RECIST v1.1, discontinuation because of disease progression, or death due to any cause

Efficacy of PRT3789 monotherapy and in combination with docetaxel: Clinical benefit rate (CBR)Baseline through approximately 3 years

Best overall response of CR, PR, or durable stable disease (24 weeks or longer duration), as assessed by the investigator per RECIST v1.1

Pharmacokinetic profile of PRT3789 monotherapy and in combination with docetaxel: Maximum observed plasma concentrationBaseline through approximately 3 years

Pharmacokinetics will be calculated including the maximum observed plasma concentration

Pharmacokinetic profile of PRT3789 monotherapy and in combination with docetaxel: Area under the curveBaseline through approximately 3 years

Pharmacokinetics will be calculated including the area under the plasma concentration versus time curve (AUC)

Trial Locations

Locations (32)

University of California, Davis Comprehensive Cancer Center

🇺🇸

Sacramento, California, United States

UCLA Hematology/Oncology - Santa Monica

🇺🇸

Santa Monica, California, United States

Smilow Cancer Hospital Phase 1 Unit

🇺🇸

New Haven, Connecticut, United States

AdventHealth Medical Group Oncology Research at Celebration

🇺🇸

Celebration, Florida, United States

Mayo Clinic, Jacksonville

🇺🇸

Jacksonville, Florida, United States

Winship Cancer Institute

🇺🇸

Atlanta, Georgia, United States

Northwestern Memorial Hospital

🇺🇸

Chicago, Illinois, United States

Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins

🇺🇸

Baltimore, Maryland, United States

Massachusetts General Hospital

🇺🇸

Boston, Massachusetts, United States

Dana Farber Cancer Institute

🇺🇸

Boston, Massachusetts, United States

Mayo Clinic, Rochester

🇺🇸

Rochester, Minnesota, United States

Washington University School of Medicine - Siteman Cancer Center

🇺🇸

Saint Louis, Missouri, United States

Laura & Isaac Perlmutter Cancer Center at NYU Langone Health

🇺🇸

New York, New York, United States

New York Presbyterian Hospital - Columbia University Medical Center

🇺🇸

New York, New York, United States

Memorial Sloan Kettering Cancer Center

🇺🇸

New York, New York, United States

University Hospitals Cleveland Medical Center

🇺🇸

Cleveland, Ohio, United States

Cleveland Clinic

🇺🇸

Cleveland, Ohio, United States

Providence Cancer Institute Franz Clinic

🇺🇸

Portland, Oregon, United States

The University of Texas MD Anderson Cancer Center

🇺🇸

Houston, Texas, United States

NEXT Virginia

🇺🇸

Fairfax, Virginia, United States

lnstitut Bergonie Centre Regionale de Lutte Contre le cancer, Service Oncologie-Medicale

🇫🇷

Bordeaux, France

Centre Leon Berard

🇫🇷

Lyon Cedex 08, France

lnstitut Paoli Calmettes

🇫🇷

Marseille, France

Oncopole Claudius Regaud IUCT ONCOPOLE

🇫🇷

Toulouse, France

Institut Gustave Roussy

🇫🇷

Villejuif Cedex, France

Leids Universitair Medisch Centrum

🇳🇱

Leiden, Netherlands

National University Hospital

🇸🇬

Singapore, Singapore

National Cancer Centre Singapore

🇸🇬

Singapore, Singapore

START Barcelona - HM Nou Delfos

🇪🇸

Barcelona, Spain

Hospital Universitario Vall d'Hebron

🇪🇸

Barcelona, Spain

START MADRID - FJD Hospital Universitario Fundacion Jimenez Diaz

🇪🇸

Madrid, Spain

Hospital Universitario HM Sanchinarro

🇪🇸

Madrid, Spain

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