This partially randomized phase Ib/II trial studies the side effects and best dose of taselisib when given together with enzalutamide and to see how well they work in treating patients with androgen receptor positive triple-negative breast cancer that has spread to other places in the body. Taselisib is a PI3K inhibitor. The PI3K pathway is involved is cancer growth. Androgen may cause the growth of tumor cells. Enzalutamide may stop the growth of tumor cells by blocking the androgen receptor from working. Giving taselisib with enzalutamide may be a better treatment for patients with breast cancer.
PRIMARY OBJECTIVES: I. To determine the safety and tolerability of taselisib given in combination with enzalutamide: Assessment of dose limiting toxicities (DLTs) during the first 4 weeks of treatment (cycle 1). (Phase Ib) II. To determine the safety and tolerability of taselisib given in combination with enzalutamide: Determination of the maximally tolerated dose (MTD) of taselisib given in combination with enzalutamide. (Phase Ib) III. To evaluate the efficacy, as measured by clinical benefit rate (CBR), of enzalutamide + taselisib in patients with androgen receptor positive (AR+) triple negative (TN) metastatic breast cancer (MBC). (Phase II) SECONDARY OBJECTIVES: I. To determine the progression free survival (PFS) of enzalutamide + taselisib in patients with AR+ TN MBC. II. To assess the pharmacokinetics (PKs) of taselisib and enzalutamide in patients with AR+ TN MBC. TERTIARY OBJECTIVES: I. To explore predictors of biomarker response and mechanisms of resistance based on exploratory analysis of tumor tissue obtained through biopsies. II. Levels of phosphatase and tensin homolog (PTEN) expression by immunohistochemistry (IHC) and quantitative real-time polymerase chain reaction (qPCR). III. Presence of mutations in the phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit alpha (PIK3CA) gene. IV. Human epidermal growth factor receptor 2 (HER2) (IHC, fluorescence in situ hybridization \[FISH\]) and estrogen receptor (ER)/progesterone receptor (PR) levels (IHC) in tumor biopsy from a metastatic site. V. Levels of mitogen-activated protein kinase kinase (MEK) activity measured by phosphorylated extracellular-signal-regulated kinases (p-ERK1/2) (IHC) and phosphorylated p-ribosomal protein S6 (S6) (S235/236 and S240/244) at baseline and upon progression of disease. VI. Levels of phosphorylated v-akt murine thymoma viral oncogene homolog 1 (p-AKT) (IHC) at baseline and upon progression of disease. VII. Gene expression profiling to assign a triple negative subtype. VIII. Whole exome deoxyribonucleic acid (DNA)-sequencing (seq) on DNA isolated at baseline and upon progression. IX. Plasma for circulating tumor DNA (ctDNA) analysis to assess PIK3CA mutation status in response and resistance. X. To assess the predictive effects of PIK3CA mutations and PTEN loss on PFS and CBR. XI. To evaluate the ability of multi-parametric magnetic resonance imaging (MRI) performed early in therapy to predict both biological and clinical response. OUTLINE: This is a phase Ib, dose-escalation study of taselisib followed by a randomized phase II study. PHASE IB: Patients receive taselisib orally (PO) once daily (QD) on days 1-28 and enzalutamide PO QD on days 9-28 of course 1 and days 1-28 of subsequent courses. Courses repeat every 28 days in the absence of disease progression or unacceptable toxicity. PHASE II: Patients are randomized to 1 of 2 treatment arms. ARM I: Patients receive taselisib PO QD and enzalutamide as in Phase Ib. Courses repeat every 28 days in the absence of disease progression or unacceptable toxicity. Patients experiencing unacceptable toxicity due to enzalutamide may continue to receive taselisib. ARM II: Patients receive enzalutamide PO QD on days 1-28. Courses repeat every 28 days in the absence of disease progression or unacceptable toxicity. Upon disease progression, patients may crossover to Arm I. After completion of study treatment, patients are followed up for 30 days and then every 3 months for 3 years.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
30
Correlative studies
Given PO
Correlative studies
Given PO
University of Alabama, Birmingham
Birmingham, Alabama, United States
Georgetown University
Washington D.C., District of Columbia, United States
University of Chicago
Chicago, Illinois, United States
Indiana University
Indianapolis, Indiana, United States
John Hopkins University
Baltimore, Maryland, United States
Dana Farber Cancer Institute
Boston, Massachusetts, United States
University of Michigan
Ann Arbor, Michigan, United States
Mayo Clinic
Rochester, Minnesota, United States
University of North Carolina
Chapel Hill, North Carolina, United States
University of Pittsburgh
Pittsburgh, Pennsylvania, United States
...and 2 more locations
Clinical Benefit Rate (CBR) - Phase II
CBR is defined as the proportion of patients with a best response of complete response (CR), partial response (PR), or (SD) stable disease per RECIST criteria 1.1. CR: Disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) must have reduction in short axis to \<10 mm. PR: At least a 30% decrease in the sum of diameters of target lesions. PD: At least a 20% increase in the sum of diameters of target lesions, taking as reference the smallest sum on study. In addition, the sum must also demonstrate an absolute increase of at least 5 mm. SD: Neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for PD, taking as reference the smallest sum of diameters while on study. It is calculated as the mean of binomial distribution.
Time frame: At 16 weeks
Maximum Tolerated Dose (MTD) of Taselisib Combined With 160mg Enzalutamide - Phase I
defined as the highest dose tested in which a dose limiting toxicity is experienced by 0 out of 3 or 1 out of 6 patients among the dose levels. Dose limiting toxicity will be graded according to the National Cancer Institute CTCAE version 4.0.
Time frame: 4 weeks
Overall Progression-Free Survival (PFS) of Patients Treated With Enzalutamide and Taselisib
The PFS time is defined as the time from treatment start to progression or death (whichever comes first), and those alive without progression were censored at the last date of follow up. PFS will be estimated using the Kaplan-Meier method. The median with 95% confidence intervals will be reported.
Time frame: Time from course 1, day 1 until objective tumor progression, assessed up to 3 years
Pharmacokinetic Profile
Pharmacokinetic sampling will occur in the phase Ib portion and in 10 patients in the phase II portion
Time frame: Approximately 4 months
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