-  INCLUSION CRITERIA:

          -  Adult (greater than or equal to 18 years) subjects with:

               -  histologically or cytologically confirmed solid tumors (Phase IA).

        OR

        --histologically or cytologically confirmed pancreatic or breast cancer (Phase IB)

        OR

          -  Pediatric (greater than or equal to 12 and < 18 years) subjects with histologically or
             cytologically confirmed solid tumors other than rhabdomyosarcoma or related skeletal
             muscle tumors (Phase IB).

          -  Subjects must have disease that:

               -  is not amenable to potentially curative resection,

               -  spread at least to one other organ system other than primary tumor,

               -  has site measurable per RECIST 1.1,

               -  progressed on or after at least one line of standard systemic chemotherapy (Phase
                  IA and IB1)

               -  have no standard therapy option available (Phase IB2)

          -  Patients must have recovered from any acute toxicity related to prior therapy or
             surgery or disease to a grade 1 or less.

          -  Performance status

             --Karnofsky greater than or equal to 70% (for patients greater than or equal to16
             years old), Lansky greater than or equal 70% (for patients <16 years old)

          -  Adequate hematological function defined by:

               -  absolute neutrophil count (ANC) greater than or equal to 1.0 (SqrRoot) 10(9)/L,

               -  transfusion-independent platelet count greater than or equal to 100 (SqrRoot)
                  10(9)/L,

               -  Hgb greater than or equal to 9 g/ dL (patients who have received less than or
                  equal to 2 PRBC transfusions within 48 hours are eligible)

          -  Adequate coagulation as defined by:

             --INR<1.5 (or < 3.0 if subjects are currently taking anticoagulated medications) Note:
             increase of the upper limit of INR is restricted only to subjects who are receiving
             anticoagulation for medical reasons (DVT/PE prophylaxis, treatment for a
             thromboembolic event) and have increased INR because of these medications. Patients
             who have an elevated INR due to compromised liver function or any other medical
             conditions remain excluded

          -  Adequate hepatic function defined by:

               -  a total bilirubin level less than or equal to 1.5 (SqrRoot) ULN, (total bilirubin
                  less than or equal to 2.0 x ULN in case of prior diagnosis of Gilbert syndrome)

               -  an AST level less than or equal to 3(SqrRoot) ULN

               -  an ALT level less than or equal to 3 (SqrRoot) ULN

          -  Adequate renal function defined by:

               -  Creatinine OR Measured or calculated creatinine clearance (CrCl) (eGFR may also
                  be used in place of CrCl)

                    -  less than 1.5x institution upper limit of normal OR

                    -  greater than 45 mL/min/1.73 m2 for participant with creatinine levels > 1.5
                       X institutional ULN

               -  Creatinine clearance (CrCl) or eGFR should be calculated per institutional
                  standard.

          -  The effects of the study treatment on the developing human fetus are unknown; thus,
             women of childbearing potential and men must agree to use adequate contraception
             (hormonal or barrier method of birth control; abstinence) prior to study entry, for
             the duration of study participation and up to 120 days after the last dose of the
             study drug(s). Should a woman become pregnant or suspect she is pregnant while she or
             her partner is participating in this study, she should inform her treating physician
             immediately.

          -  Weight > 35 kg.

          -  Ability of subject or parent/guardian to understand and the willingness to sign a
             written informed consent document.

          -  Subjects must have lesion(s) accessible for biopsy (other than used for measurement of
             disease) and be willing to undergo mandatory study biopsies (Cohort IB1 only).

          -  Ability to swallow oral capsules.

        EXCLUSION CRITERIA:

          -  Anticancer treatment within designated period before treatment initiation including:

               -  minor surgical procedure (such as biliary stenting) within 14 days;

               -  major surgical procedure or curative radiation treatment within 28 days;

               -  palliative radiation treatment within 14 days;

               -  chemotherapy or experimental drug treatment with published half-life known to be
                  72 hours or less within 14 days;

               -  experimental drug treatment with unpublished or half-life greater than 72 hours
                  within 28 days;

               -  chemotherapy regimen containing an alkylating antineoplastic agent
                  (cyclophosphamide, chlorambucil, melphalan, or ifosfamide), alkylating-like
                  (platinumbased chemotherapeutic drugs, platinum analogues), and non-classical
                  alkylating agent (dacarbazine, temozolomide) within 28 days.

          -  Patients receiving any medications or substances that are moderate and strong
             inhibitors or inducers of CYP3A4 and are not able to safely stop these medications are
             excluded from this study; patients must stop strong CYP3A4 inhibiting/inducing
             medications within 5 published half-lives and moderate within 3 published half-lives
             prior to the treatment initiation.

        Note: dihydropyridinecalcium - channel blockers are permitted for management of underling
        disease

          -  Subjects with cardiomyopathy diagnosed within 6 months prior to treatment initiation
             including but not limited to the following:

               -  hypertrophic cardiomyopathy

               -  arrhythmogenic right ventricular cardiomyopathy

               -  abnormal ejection fraction (echocardiogram [ECHO]) <= 53% (if a range is given
                  then the upper value of the range will be used)

               -  previous moderate or severe impairment of left ventricular systolic function
                  (LVEF <45%)

               -  severe valvular heart disease

               -  atrial fibrillation with a ventricular rate >100 bpm on EKG at rest

               -  Fridericia's corrected QT interval (QTcF) >= 480 msec (adults) or >= 460 msec
                  (pediatric subjects, aged 12 to <18 years) or other factors that increase the
                  risk of QT prolongation or arrhythmic events (e.g., heart failure, hypokalemia,
                  family history of long QT interval syndrome.

          -  HIV, HCV, HBV positive patients on antiviral drugs are excluded due to the absence of
             previous experience with concurrent use of antiviral medications and the
             investigational drug product to be evaluated in the current study and possible for
             adverse pharmacokinetic and/or pharmacodynamic interactions.

          -  Previous malignant disease (other than the target malignancy to be investigated in
             this trial) within the last 3 years. Note: subjects with a history of cervical
             carcinoma in situ, superficial or non-invasive bladder cancer, or basal cell or
             squamous cell carcinoma in situ previously treated with curative intent are NOT
             excluded.

          -  Rapidly progressive disease which, in the opinion of the Investigator, may predispose
             to inability to tolerate treatment or trial procedures.

          -  Subjects with central nervous system (CNS) metastases or CNS disorders known to
             increase possible neurotoxicity of metarrestin in case of compromised blood-brain
             barrier (e.g. recent stroke (less than 3 months of treatment initiation). infectious
             causes).

          -  Significant acute or chronic infections including tuberculosis with presence of
             clinical symptoms or physical findings.

          -  Patients with a history of any seizures or increased risk of seizures on screening
             EEGs defined by 1) interictal epileptiform discharges, 2) temporal intermittent
             rhythmic delta activity (TIRDA), or 3) electrographic or clinical seizures on EEG.

          -  Clinically relevant diseases (for example, inflammatory bowel disease) and / or
             uncontrolled medical conditions, which, in the opinion of the Investigator, might
             impair the subject's tolerance or ability to participate in the trial.

          -  Patients with previous gastric bypass, patients receiving nutrition via feeding tubes
             or parenterally, or patients with malabsorptive conditions (damage to the intestine
             from infection, inflammation, trauma, or surgery, celiac disease, Crohn's disease,
             chronic pancreatitis, or cystic fibrosis resulting malabsorption). Patients with
             refractory nausea and vomiting. Note: patients with gastric banding are allowed.

          -  Pregnant women are excluded from this study because metarrestin potential for
             teratogenic or abortifacient effects is unknown. Because there is an unknown but
             potential risk for adverse events in nursing infants secondary to treatment of the
             mother with metarrestin, breastfeeding should be discontinued if the mother is treated
             with study drug.