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

 -  No deleterious germline BRCA1 or BRCA2 mutation based on full sequencing and
 comprehensive rearrangement testing at an external reference laboratory; patients with
 variants of unknown significance will be eligible

 -  Measurable disease per Response Evaluation Criteria In Solid Tumors (RECIST) version
 1.1

 -  Must have progressed on at least 1 prior chemotherapy regimen for the treatment of
 advanced breast cancer; there is no upper limit on the number of prior therapies

 -  If prior platinum agent (eg, carboplatin or cisplatin) has been administered, no
 evidence of progression, or within 8 weeks of stopping platinum treatment

 -  Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 2

 -  Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤ 2.5 x
 upper limit of normal (ULN); if liver function abnormalities are due to hepatic
 metastasis, then AST and ALT ≤ 5 x ULN

 -  Total serum bilirubin ≤ 1.5 x ULN (≤ 3 x ULN for Gilbert's syndrome)

 -  Calculated creatinine clearance ≥ 30 mL/min or serum creatinine ≤ 1.5 mg/dL

 -  Hemoglobin ≥ 9.0 g/dL with last transfusion at least 14 days before day 1 of study
 drug

 -  Absolute neutrophil count (ANC) ≥ 1500/mm^3

 -  Platelet count ≥ 100,000/mm^3

 -  Able to take oral medications

 -  Willing and able to provide written, signed informed consent after the nature of the
 study has been explained, and prior to any research-related procedures

 -  Sexually active patients of childbearing potential must be willing to use an
 acceptable method of contraception such as an intrauterine device or double barrier
 contraception during treatment and for 30 days after the last dose of study drug

 -  Females of childbearing potential must have a negative serum pregnancy test at
 screening and be willing to have additional serum pregnancy tests during the study;
 females considered not of childbearing potential include those who have been in
 menopause at least 2 years, or had tubal ligation at least 1 year prior to screening,
 or who have had total hysterectomy

 -  Willing and able to comply with all study procedures

 -  COHORT A SPECIFIC ELIGIBILITY CRITERIA:

 -  Histologically-confirmed metastatic or recurrent triple-negative breast cancer
 (defined as estrogen receptor ≤ 5%, progesterone receptor ≤ 5%, HER2-negative via
 immunohistochemistry [IHC] or fluorescent in situ hybridization [FISH])

 -  An homologous recombination deficiency (HRD) score ≥ 42 on the HRD Assay as
 assessed on a tumor biopsy sample; in the case that obtaining an adequate
 metastatic tumor biopsy is not possible, we will assess the HRD score from the
 primary breast tumor

 -  COHORT B SPECIFIC ELIGIBILITY CRITERIA:

 -  Histologically-confirmed metastatic or recurrent HER2-negative (via IHC or FISH)
 breast cancer or other histologically-confirmed metastatic solid tumor

 -  Deleterious germline or somatic mutation implicated in the homologous
 recombination (HR) pathway, excluding BRCA1 or BRCA2, based on germline multiplex
 gene testing or direct tumor next generation DNA sequencing. Genes of interest
 include: PTEN, PALB2, CHEK2, ATM, NBN, BARD1, BRIP1, RAD50, Rad51c, Rad51d,
 MRE11, ATR, FANCA, FANCC, FANCD2, FANCE, FANCF, FANCG, FANCL, plus other
 HR-related genes at the discretion of the primary investigators.

 EXCLUSION CRITERIA:

 -  Any patient with a deleterious mutation in BRCA1 or BRCA2

 -  Hormone receptor positive and/or HER2 positive breast cancer (Cohort A only)

 -  HER2 positive breast cancer (Cohort B only)

 -  Prior treatment with a PARP inhibitor

 -  Non-measurable disease only

 -  Pregnant or nursing patients

 -  Any anti-cancer therapy within the past 21 days of the first day of treatment

 -  Brain or central nervous system (CNS) metastases

 -  Exception: Adequately treated brain metastases documented by baseline computed
 tomography (CT) or magnetic resonance imaging (MRI) scan that have not progressed
 since previous scans and do not require corticosteroids (except prednisone ≤ 5
 mg/day or equivalent) for management of CNS symptoms. A repeated CT or MRI
 following the identification of CNS metastases (obtained at least 2 weeks after
 definitive therapy) must document adequately treated brain metastases

 -  Subjects with leptomeningeal carcinomatosis are not permitted

 -  Other malignancy that is either active or for which patient has received treatment in
 the last five years excluding non-melanoma skin cancer and carcinoma in situ of the
 cervix

 -  Radiation therapy in the last 14 days

 -  Known to be human immunodeficiency virus positive

 -  Known active hepatitis C virus

 -  Known active hepatitis B virus

 -  Use of any investigational product or investigational medical device within 28 days
 before day 1 of study drug

 -  Major surgery requiring a prolonged hospitalization or recovery within 21 days before
 day 1 of study drug

 -  Concurrent disease or condition that would interfere with study participation or
 safety, such as any of the following:

 -  Active, clinically significant infection either grade > 2 by National Cancer
 Institute (NCI) Common Terminology Criteria for Adverse Events (CTCAE) version
 4.0 or requiring the use of parenteral anti-microbial agents within 7 days before
 day 1 of study drug

 -  Clinically significant bleeding diathesis or coagulopathy, including known
 platelet function disorders

 -  Known hypersensitivity to any of the components of BMN 673