Phase II Trial of Talazoparib in BRCA1/2 Wild-type HER2-negative Breast Cancer and Other Solid Tumors

Phase 2

Completed

Conditions: Advanced Breast Cancer
HER2/Neu Negative
Triple-Negative Breast Cancer

Brief Summary: The aim of this single-arm phase 2 clinical trial is to evaluate the anti-cancer activity of Talazoparib (also known as BMN 673) in patients with advanced breast cancer with specific genetic or tumor genomic alterations. Patients with either triple-negative or HER2-negative breast cancer are eligible.

Detailed Description: Talazoparib (BMN 673) is a novel, dual-mechanism PARP inhibitor that potently inhibits the PARP enzyme and effectively traps PARP on DNA. Talazoparib has shown promising single-agent anti-tumor efficacy in several BRCA1/2 mutation-associated advanced cancers. The efficacy of PARP inhibition in BRCA1/2 wild-type TNBC with homologous recombination (HR) defects and in breast tumors with mutations in other non-BRCA1/2 HR pathway genes is currently unknown.

This phase 2 trial explores the activity of single agent talazoparib in BRCA1/2 wild-type BC patients using an optimal Simon two-stage design. Eligible subjects will be assigned to one of two parallel cohorts: 1) Cohort A: Subjects (n=29) with advanced TNBC with underlying HR defects as assessed by the HRD assay and, 2) Cohort B: Subjects (n=29) with advanced HER2-negative BC with a somatic or germline mutation in a non-BRCA1/2 HR pathway gene. Gene mutations of interest are: PTEN, PALB2, CHEK2, ATM, NBN, BARD1, BRIP1, RAD50, RAD51C, RAD51D, MRE11, ATR, Fanconi anemia complementation group of genes (FANCA, FANCC, FANCD2, FANCE, FANCF, FANCG, FANCL).

Recruitment & Eligibility

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Arm && Interventions

Group	Intervention	Description
Cohort A - Triple-negative Breast Cancer	Talazoparib Tosylate	Participants with advanced triple-negative breast cancer (TNBC) with homologous recombination deficiency (HRD) based on the Myriad HRD Assay. Participants receive talazoparib 1 mg by mouth daily.
Cohort B - HER2-negative solid tumor	Talazoparib Tosylate	Participants with advanced HER2-negative solid tumor with a deleterious hereditary or cancer somatic mutation in one of the following genes: PTEN, PALB2, CHEK2, ATM, NBN, BARD1, BRIP1, RAD50, RAD51C, RAD51D, MRE11, ATR, Fanconi anemia complementation group of genes. Participants receive talazoparib 1 mg by mouth daily.

Primary Outcome Measures

Name	Time	Method
Objective Response (OR)	up to 24 weeks	Objective response (OR) is a common measure of benefit. OR is defined as the number of participants who achieved complete response (CR) or partial clinical (PR), per the Response Evaluation Criteria in Solid Tumors (RECIST) Criteria (v1.1). RECIST Criteria are assessed by physical measurement; magnetic resonance imaging (MRI); computed tomography (CT), positron emission tomography (PET)-CT; and/or X-rays, as follows: * CR = Disappearance of all target and non-target lesions * PR = ≥30% decrease in the sum of the long diameter of target lesions * OR = CR+PR * Stable disease (SD) = Small changes that do not meet any of the above criteria * Progressive disease (PD) = ≥20% increase in long diameter of target lesions, and/or the appearance of any new lesion(s) The outcome is expressed as the number of participants that achieved either CR or PR within 24 weeks of the start of treatment, a number without dispersion.

Secondary Outcome Measures

Name	Time	Method
Clinical Benefit (CB)	up to 24 weeks	Clinical benefit (CB) is a common measure of benefit. CB is defined as the number of participants who achieved complete response (CR); partial clinical (PR); or stable disease (SD), per the Response Evaluation Criteria in Solid Tumors (RECIST) Criteria (v1.1). RECIST Criteria are assessed by physical measurement; magnetic resonance imaging (MRI); computed tomography (CT), positron emission tomography (PET)-CT; and/or X-rays, as follows: * CR = Disappearance of all target and non-target lesions * PR = ≥30% decrease in the sum of the long diameter of target lesions * SD = Small changes that do not meet any of the above criteria * CB = CR+PR+SD * Progressive disease (PD) = ≥20% increase in long diameter of target lesions, and/or the appearance of any new lesion(s) The outcome is expressed as the number of participants that achieved either CR, PR, or SD within 24 weeks of the start of treatment, a number without dispersion.
Progression-free Survival (PFS)	1 year	Progression-free survival (PFS) is a common measure of benefit. PFS means to remain alive with disease or tumor progression. Progression was defined per the Response Evaluation Criteria in Solid Tumors (RECIST) Criteria (v1.1) as any ≥20% increase in long diameter of the target lesions, and/or the appearance of any new lesion(s). PFS is expressed as the number of participants who remained alive without progression after 1 year, a number without dispersion.