Subject has a history of seizures within 12 months of Cycle 1 Day-2 or diagnosed neurological condition placing subject at the increased risk of seizures. Patients with a known history of seizures must have well-controlled seizures and may not be receiving enzyme-inducing anti-convulsants Seizures within the past 12 months before enrollment History of seizures More than 2 seizures over the last 4 weeks prior to study entry Patients with intractable seizures Central Nervous System (CNS) Function defined as subjects with a known history of seizures must have well-controlled seizures and may not be receiving enzyme-inducing anti-convulsants, CNS toxicity <= Grade 2. New onset seizures (within 3 months before planned randomization) or poorly controlled seizures Patients with uncontrolled seizures defined as seizures that require regular use of rescue medications or in the opinion of the investigator require increasing doses of anti-epileptic medications or would compromise the ability to tolerate study therapy or interfere with protocol therapy or procedures; patients with seizures that are well controlled are eligible and may be on antiepileptic medications if on a stable dose EXCLUSION CRITERIA FOR STRATUM C: Patients with uncontrolled seizures defined as seizures that require regular use of rescue medications or in the opinion of the investigator require increasing doses of antiepileptic medications or would compromise the ability to tolerate study therapy or interfere with protocol therapy or procedures; patients with seizures that are well controlled are eligible and may be on antiepileptic medications if on a stable dose Patients with a confirmed history of encephalitis, meningitis, or uncontrolled seizures in the year prior to signing informed consent are ineligible History of uncontrolled seizures within 6 months of randomization History of seizures No history of seizures, encephalitis, or multiple sclerosis History or evidence upon physical/neurological examination of central nervous system disease (e.g., seizures) unrelated to cancer unless adequately controlled by medication; History of seizures History of seizures History of seizures in the past 3 years New onset seizures (within 3 months prior to screening) or poorly controlled seizures History of central nervous system disease (e.g., seizures) unrelated to cancer unless adequately controlled by medication Encephalitis, meningitis, or uncontrolled seizures in the year prior to informed consent History of seizures Subjects with a history of seizures History of HIV-associated encephalopathy; dementia of any kind; seizures in the past 12 months Patients with a history of seizures with in the past 3 months History of seizures, movement disorders or cerebrovascular accident within the past 1 year prior to cycle 1 day 1 Prior seizures while on enzalutamide therapy Patients who receive treatment with antiepileptic medications must have a two week history of stable dose of antiepileptic without seizures prior to dosing Have experienced >2 seizures within 4 weeks prior to study entry. History of seizures History of significant bleeding disorder or uncontrolled seizures History of significant neurologic or psychiatric disorders including dementia or seizures History of seizures or extrapyramidal symptoms Encephalitis, meningitis, or uncontrolled seizures in the year prior to informed consent Patients with seizures due to CNS metastases must be controlled with stable anti-epileptic treatment for > 14 days Patients with stable seizures (e.g., no seizures for >= 14 days and not requiring escalation or addition of anti-epileptic drugs) will be eligible History of uncontrolled seizures; (Note: patients are eligible for the study if the seizures are well controlled with standard medications) Subjects who have experienced a seizure or seizures within 6 months of study treatment or who are currently being treated with cytochrome P450 enzyme inducing anti-epileptic drugs for seizures (use of anti-epileptic drugs to control pain is allowed in subjects not suffering from seizures unless drug is excluded due to Cytochrome P450 3A4 induction - phenytoin, carbamazepine, Phenobarbital. TUMOR BIOPSY SEQUENCING: Patients with history of central nervous system (CNS) metastases who have received treatment and who either have not had seizures or have been on stable doses of anti-seizure medicine and had no seizures for 4 weeks will be eligible; enzyme-inducing anticonvulsants are contraindicated TREATMENT: Patients with a history of seizures are not eligible to receive veliparib, but patients with a history of CNS metastases who have received treatment and who either have not had seizures or have been on stable doses of anti-seizure medicine and had no seizures for >= 4 weeks will be eligible for other study agents; enzyme inducing anticonvulsants are contraindicated TREATMENT: Patients with active brain metastases or carcinomatous meningitis are excluded from this clinical trial; patients who have a history of seizures are not eligible to receive veliparib, but patients who have either not had seizures or who have been on stable doses of anti-seizure medicine and had no seizures for 4 weeks will be eligible for other study agents; enzyme-inducing anticonvulsants are contraindicated New onset seizures (within 3 months prior to the first dose of rigosertib) or poorly controlled seizures. Any history of HIV-associated encephalopathy; dementia of any kind; seizures in the past 12 months History of seizures No brain metastasis, history of seizures, encephalitis, or multiple sclerosis Patients with history or evidence upon physical examination of central nervous system (CNS) disease, including primary brain tumor, seizures or history of seizures, and/or any CNS metastases are ineligible For Cohort A: Has experienced a seizure or seizures within 6 months of study start or is currently being treated with cytochrome P450 enzyme (CYP) inducing anti-epileptic drugs for seizures Patients must not have a history of seizures Seizures occurrence or the requirement of escalation (or addition) of anti-epileptic drugs Subjects with a history of seizures must be on a stable dose of anti-epileptic drugs (AEDs) and without seizures for 14 days prior to enrollment in patients enrolled prior to Amendment 2. Subjects enrolled after Amendment 2 is approved with a history of seizures must be on a stable dose of anti-epileptic drugs (AEDs) for 7 days prior to enrollment. New onset seizures (within 3 months prior to Screening) or poorly controlled seizures. Presence of uncontrolled seizures =< 5 days prior first drug dose, defined as status epilepticus or multiple seizures not responding to appropriate therapy Diabetics on a stable dose of insulin or antihyperglycemic regimen are allowed if they have had no prior seizures and no history of loss of consciousness due to hypoglycemia History of seizures, movement disorders or cerebrovascular accident within the past 5 years prior to cycle 1 day 1 History of seizures, movement disorders or cerebrovascular accident within the past 5 years History of seizures, movement disorders or cerebrovascular accident within the past 3 years prior to cycle 1 day 1 More than 2 seizures over the last 4 weeks prior to study entry Brain metastases are allowed if well controlled and without seizures Seizures or history of seizures Patients with history of active seizures are not eligible More than two seizures over the last 4 weeks prior to study entry g. Untreated and uncontrolled epileptic seizures History of seizures. History of significant neurologic or psychiatric disorders, including dementia or seizures that would impede consent, treatment, or follow up History of prior seizures History of seizures, movement disorders or cerebrovascular accident within the past 5 years prior to cycle 1 day 1 History of seizures, movement disorders or cerebrovascular accident within the past 3 years prior to cycle 1 day 1 Patients with a prior history of seizures within the past year unrelated to brain metastases Encephalitis, meningitis, or uncontrolled seizures in the year prior to informed consent History of epilepsy or seizures in the past 20 years. Patients with uncontrolled seizures or any neurological conditions resulting in increased risk for seizures are not eligible for study entry No history of seizures Recurring seizures resulting from the head injury Any disorder that would predispose the participant to seizures History of seizures No history of epilepsy/seizures History of seizures History of seizures Patients with tumor-induced seizures must be well controlled on a stable anti-epileptic treatment No history of seizures related to the brain metastases or LMD. History of any neurological disorders or seizures. History of seizures