ESK981 in Treating Patients With Metastatic Castrate-Resistant Prostate Cancer

Inclusion Criteria:

Have signed an informed consent document indicating that the subject understands the purpose of and procedures required for the study and are willing to participate in the study
Be willing/able to adhere to the prohibitions and restrictions specified in this protocol
Eastern Cooperative Group (ECOG) performance status =< 1
Patient must have evidence of castrate resistant prostate cancer as evidenced by a confirmed rising PSA (per PCWG3 criteria) and a castrate serum testosterone level (i.e. =< 50 mg/dL)
Documented histologically confirmed adenocarcinoma of the prostate
Metastatic prostate cancer (M1) as documented by appropriate medical imaging (i.e. computed tomography [CT]-scan, positron emission tomography [PET] scan or bone scan)
Treatment failure of either abiraterone and/or enzalutamide as evidenced by a confirmed rising PSA (per PCWG3 criteria) and a castrate serum testosterone level (i.e. =< 50 mg/dL) while receiving treatment with either abiraterone and/or enzalutamide
Willingness to use contraception by a method that is deemed effective by the Investigator throughout the treatment period and for at least 30 days following the last dose of therapy
Willingness and ability to comply with study procedures and follow-up examination
Able to swallow and retain oral medication

Exclusion Criteria:

Current systemic therapy (other than a gonadotrophin releasing hormone [GnRH] agonist/antagonist) for CRPC including:

CYP-17 inhibitors (e.g. ketoconazole, abiraterone)
Antiandrogens (e.g. bicalutamide, nilutamide)
Second generation antiandrogens (e.g. enzalutamide, ARN-509, Galeterone)
Immunotherapy (e.g. sipuleucel-T, ipilimumab)
Chemotherapy (e.g. docetaxel, cabazitaxel)
Greater than 2 lines of prior systemic therapy for CRPC
Prior chemotherapy (e.g. docetaxel, cabazitaxel) for CRPC; prior docetaxel administered in the castrate-sensitive space is allowed
Prior radiopharmaceutical therapy (e.g. radium-223, strontium-89, samarium-153, etc.) within the past year
Have any condition that, in the opinion of the investigator, would compromise the well-being of the subject or the study or prevent the subject from meeting or performing study requirements
Absolute neutrophil count (ANC) less than 1500/mm^3
Platelet count less than 100000/mm^3
Hemoglobin less than 9 g/dL
Bilirubin greater than 1.5 times the upper limit of normal (ULN)
Alanine aminotransferase (ALT) or aspartate aminotransferase (AST) greater than 2.0 times the ULN in the absence of known hepatic metastases, or ALT or AST greater than 3.0 times the ULN in the presence of known hepatic metastases
The patient has a serum creatinine value greater than 1.5 mg/dL
The patient has active brain metastases
The patient is currently on warfarin or heparin therapy
The patient has any pre-existing coagulopathy, recent hemoptysis, gross hematuria, or gastrointestinal bleeding, and a history of a clinically significant cardiovascular or cerebrovascular event within 12 months prior to study entry
The patient has uncontrolled hypertension defined as a blood pressure measurement greater than 150 mm Hg systolic or 90 mm Hg diastolic with medication
The patient has received any investigational drug within the past 4 weeks
The patient has previously been enrolled in the study or received ESK981
The patient has known hypersensitivity to gelatin or lactose monohydrate
The patient has taken a medication known to be a potent inducer of CYP1A2, CYP2C8, or CYP3A4 within 4 weeks prior to the first dose of study drug
The patient has taken a medication known to be a potent inhibitor of CYP1A2, CYP2C8, or CYP3A4 within 2 weeks prior to the first dose of study drug