Participants with known or suspected CNS metastases, untreated CNS metastases, or with the CNS as the only site of disease (patients with controlled brain metastasis allowed to enroll) Has CNS metastases or symptomatic CNS involvement Known CNS disease including, but not limited to, metastases Known CNS metastases CNS metastases as shown by radiology records or clinical evidence of symptomatic CNS involvement in the last 3 months prior to randomization. Known CNS disease including, but not limited to, metastases Symptomatic CNS metastases which are neurologically unstable or requiring increasing doses of steroids to control their CNS disease. Patients with primary CNS tumors or symptomatic CNS metastases who have not undergone surgery and/or radiotherapy and/or who are not neurologically stable; Previously untreated CNS metastases or progressive CNS metastases Participants with known or suspected uncontrolled CNS metastases or with the CNS as the only site of active disease Symptomatic and/or untreated CNS metastases Patients with known symptomatic CNS metastases or lepotomeningeal disease requiring steroids. Subject has symptomatic CNS metastases. Subjects with a history of or active CNS tumors or metastases from non-CNS tumors. Radiographic evidence of CNS metastases Symptomatic central nervous system (CNS) metastases that are neurologically unstable or requiring > 5 mg/day of dexamethasone (or equivalent) to control CNS disease; note: patients with controlled CNS metastases are allowed; radiotherapy or surgery for CNS metastases must have been completed > 2 weeks prior to study entry; patients must be neurologically stable, having no new neurologic deficits on clinical examination, and no new findings on CNS imaging; steroid use for management of CNS metastases must be at a stable dose for two weeks preceding study entry Active (i.e., symptomatic or progressing) CNS metastases. Subjects with CNS metastases are eligible for the trial if: No progression of CNS metastases on MRI or CT for at least 14 days after last day of prior therapy for the CNS metastases Patients with treated or untreated asymptomatic CNS metastases may be allowed to enroll. Participants must not have suspected, known, or progressive CNS metastases, have untreated CNS metastases, or have the CNS as the only site of disease Participants with active central nervous system (CNS) metastases, untreated CNS metastases, or with the CNS as the only site of disease are excluded (controlled brain metastases will be allowed to enroll) have known uncontrolled or symptomatic CNS metastases; Subject has symptomatic CNS metastases. Patients are excluded if they have active CNS metastases. Patients with history of CNS metastases must have MRI scans that show stability of brain metastases for 8 weeks. At screening, patients with > 1 cm or > 3 in number treated CNS metastases may be included if there is no evidence of progressive CNS disease on brain imaging at least 90 days after treatment with surgery and/or radiation therapy, and if the patients with CNS metastases are not taking prednisone > 10 mg or equivalent daily Patients with > 3 untreated CNS metastases or evidence of peri-tumoral edema will be excluded, or patients with CNS metastases of any status who are taking prednisone > 10 mg or equivalent steroid daily will be excluded Patients with =< 3 untreated CNS metastases but with at least one lesion > 1 cm or peri-tumoral edema will be excluded, or patients with CNS metastases of any status who are taking prednisone > 10 mg or equivalent steroid daily will be excluded Patients with treated CNS metastases > 1 cm or > 3 in number will be excluded if there is evidence of progressive CNS disease on brain imaging at least 90 days after treatment with surgery and/or radiation therapy, or patients with CNS metastases of any status who are taking prednisone > 10 mg or equivalent will be excluded History of hemorrhagic CNS metastases Known CNS metastases, unless stable and asymptomatic. Subjects with CNS metastases may be eligible for the study, provided: Symptomatic CNS metastases or CNS metastases requiring steroids Uncontrolled CNS metastases Suspected, known, or progressive CNS metastases (Imaging required only if participants are symptomatic) Untreated CNS disease, metastases or carcinomatous meningitis. Patients with CNS metastases must be at least 2 weeks status post prior therapy to the brain and be off all steroids without progressing CNS disease or symptoms. Patients with symptomatic brain metastases are excluded; however, patients with asymptomatic central nervous system (CNS) metastases may participate in this trial; the patient must have completed any prior local treatment for CNS metastases > 28 days prior to study entry including radiotherapy or surgery; patients receiving steroids for CNS metastases may not participate on this study Patients with primary CNS tumors as well as patients with CNS metastases are excluded. Have either previously untreated intracranial CNS metastases or previously treated intracranial CNS metastases with radiologically documented new or progressing CNS lesions. Have or do not have active (untreated or progressing) CNS metastases. Uncontrolled CNS metastases, primary CNS tumors, or solid tumors with CNS metastases as only measurable disease; Active CNS metastases. Patients with CNS metastases with the following exceptions: Patients with symptomatic CNS metastases; Patients with symptomatic CNS metastases. Any active CNS metastases Patients with > 3 untreated CNS metastases or evidence of peri-tumoral edema will be excluded Patients with =< 3 untreated CNS metastases but with at least one lesion > 1 cm or peri-tumoral edema will be excluded Patients with > 3 untreated CNS metastases or evidence of peri-tumoral edema will be excluded Patients with =< 3 untreated CNS metastases but with at least one lesion > 1 cm or peri-tumoral edema will be excluded PHASE II: Patients with CNS metastases or a history of CNS metastases are ineligible Patients with active CNS metastases Patients with central nervous system (CNS) tumors or known CNS metastases are not eligible; patients with a history of CNS metastases that have been surgically resected are eligible only if the baseline evaluation shows no evidence of current CNS metastases; patients with any evidence of CNS metastases on baseline evaluation are not eligible, regardless of whether the lesions have been previously treated and/or appear stable Subjects with symptomatic CNS metastases. Subjects with untreated CNS metastases are excluded. CNS metastases Symptomatic, untreated CNS metastases Subjects with radiographic evidence of central nervous system (CNS) metastases as assessed by CT or MRI that are not well controlled (symptomatic or requiring control with continuous corticosteroid therapy [e.g., dexamethasone]) a. Note: Subjects with CNS metastases are permitted to participate in the study if the CNS metastases are medically well-controlled and stable for at least 28 days after receiving local therapy (irradiation, surgery, etc.) Symptomatic central nervous system (CNS) metastases that are neurologically unstable or requiring increasing doses of steroids to control CNS disease\r\n* Note: patients with controlled CNS metastases are allowed; radiotherapy or surgery for CNS metastases must have been completed > 2 weeks prior to study entry; patients must be neurologically stable, having no new neurologic deficits on clinical examination, and no new findings on CNS imaging; steroid use for management of CNS metastases must be at a stable dose for two weeks preceding study entry History of brain or other CNS metastases. Known uncontrolled or symptomatic CNS metastases Patient with CNS metastases. Known uncontrolled or symptomatic CNS metastases Uncontrolled central nervous system (CNS) metastases; patients are considered to have controlled CNS metastases (and thus eligible) if they have completed local therapy (radiotherapy [XRT] and/or surgery) and are off steroids with clinical and radiographic stability 1 month from the end of CNS-directed therapy CNS metastases that are symptomatic and /or requiring escalating doses of steroids. Dose escalation and MTD/RP2D expansion cohort: Patients with symptomatic CNS metastases are excluded. Patients with treated CNS metastases or untreated asymptomatic CNS metastases not requiring immediate local therapy may be eligible. Enrollment of patients with metastases must be approved by the study medical monitor. Evidence of untreated CNS metastases Any untreated CNS metastases Active CNS metastases CNS or Brain metastases Active, untreated CNS metastases. Subjects with radiographic evidence of central nervous system (CNS) metastases as assessed by computerized tomography (CT) or magnetic resonance imaging (MRI) that are not well controlled (symptomatic or requiring control with continuous corticosteroid therapy [e.g., dexamethasone]). Note: Subjects with CNS metastases are permitted to participate in the study if the CNS metastases are medically well controlled prior to screening (as assessed by the Investigator) after receiving local therapy (irradiation, surgery, etc.) Participants with untreated CNS metastases are excluded Patients with asymptomatic CNS metastases are allowed Subjects with symptomatic or unstable CNS metastases Patient has symptomatic CNS metastases. Patients with asymptomatic CNS metastases may participate in this trial. The patient must have completed any prior local treatment for CNS metastases ? 28 days prior to the start of study treatment (including radiotherapy and/or surgery) and must have stable low dose of corticosteroid therapy; Known, uncontrolled CNS metastases Leptomeningeal carcinomatosis or other untreated or symptomatic CNS metastases (asymptomatic CNS metastases allowed if clinically stable without requirement for steroids within 2 weeks) Has untreated or uncontrolled CNS metastases, including patients who require glucocorticoid therapy for CNS metastases Active, untreated CNS metastases No 'active' CNS metastases. Prior CNS metastases are allowed, provided adequate palliative therapy has been administered and CNS disease control has been established prior to study entry. • A brain MRI scan, ? 28 days from day 1, is required CNS metastases that are symptomatic and /or requiring steroids. Known, uncontrolled CNS metastases or primary CNS lymphoma CNS metastases. Known or suspected central nervous system (CNS) metastases or with the CNS as the only site of active disease (controlled CNS metastases are allowed) Symptomatic CNS metastases Newly identified CNS malignancies or documented progression of CNS metastases; subjects will be allowed only if the CNS metastases have been adequately treated with radiotherapy or surgery. For subjects receiving steroid therapy please refer to Section 6.3 for allowed steroid maintenance therapy. Symptomatic CNS metastases Symptomatic CNS metastases Symptomatic CNS metastases Symptomatic CNS metastases Patients with active CNS or other brain metastases Have known active uncontrolled or symptomatic CNS metastases CNS tumor or clinically active brain metastases.