General Phase 1 and 2 Inclusion Criteria:

1. Signed informed consent.
2. Patients age ≥18 years at signing the informed consent.
3. Histologically confirmed diagnosis of advanced or metastatic solid tumors, disease should have progressed following at least one line of therapy and no other standard therapy with proven clinical benefit is available
4. Patients with secondary metastasis to the CNS are eligible if they have met certain criteria.
5. Evaluable disease; either measurable on imaging or with informative tumor marker.
6. Discontinuation of previous cancer therapies at least three (3) weeks or 5 half-lives, whichever is shorter.
7. Eastern Cooperative Oncology Group (ECOG) performance status ≤ 2
8. Neutrophils ≥1,500 μL.
9. Platelets ≥100,000 μL.
10. Aspartate aminotransferase/alanine aminotransferase (AST/ALT) ≤ 3 upper limit of normal (ULN). In cases with liver involvement ALT/ AST ≤ 5× ULN.
11. Total bilirubin ≤1.5 mg/dL unless elevated due to known Gilbert's syndrome.
12. Creatinine ≤1.5 ULN.
13. Serum potassium within normal range.
14. If female of child-bearing potential (i.e. not postmenopausal or surgically sterile), must be willing to abstain from sexual intercourse or employ an effective barrier or medical method of contraception during the study drug administration and for at least 6 months following last treatment. If male, must be sterile or willing to abstain from sexual intercourse or employ a barrier method of contraception during the study treatment and for at least 6 months following last treatment.

General Phase 1 and 2 Exclusion Criteria:

1. Patients with primary central nervous system (CNS) cancer.
2. Patients with QTc interval >450 msec for male and >470 msec for female.
3. Patients who are on treatment with drugs known to prolong the QT/QTc interval.
4. Patients who are being treated with Valproic Acid for any of its indication (epilepsy, mood disorder) must be excluded or must stop using the medication.
5. Any serious medical condition that interferes with adherence to study procedures.
6. Prior history of solid tumor malignancy diagnosed within the last three (3) years of study enrollment excluding adequately treated basal cell carcinoma of the skin, squamous cell carcinoma of the skin, or in situ cervical cancer, in situ breast cancer, in situ prostate cancer (patients must have shown no evidence of active disease for 2 years prior to enrollment)
7. Pregnant or breast feeding females.
8. New York Heart Association (NYHA) stage III/IV congestive heart failure, arrhythmias not adequately controlled, or other significant co-morbidities [e.g. active infection requiring systemic therapy, history of human immunodeficiency virus (HIV) infection, or active Hepatitis B or Hepatitis C].
9. Use of other investigational agents within 30 days or 5 half-lives prior to the first dose of study drug. As long as patient has recovered from any related toxicities ≥ Grade 1.
10. Steroid treatment within seven (7) days prior to study treatment. Patients that require intermittent use of bronchodilators, topical steroids or local steroid injections will not be excluded from the study. Patients who have been stabilized to 10 mg Prednisolone PO QD (or equivalent), daily (or less) at least seven (7) days prior to study drug administration are allowed.

Phase 2 Tumor-specific Eligibility Criteria

Phase 2 patients must meet the cohort-specific inclusion/exclusion criteria in addition to the general inclusion/exclusion criteria for Phase 1 and Phase 2 study listed above.

Cohort 1: Patient Population: Relapsed/Refractory SCLC

1. Histologically or cytologically confirmed limited or extensive disease stage of SCLC. The disease should be progressing during or relapsing after the previous treatment.
2. At least one line of prior combination and no other standard therapy with proven clinical benefit is available.
3. At least 3 weeks or 5 half-lives, whichever is shorter, should have elapsed since prior treatment as long as the patient recovered from any related toxicities to ≤ Grade 1.
4. Prior radiotherapy is acceptable provided the patient has recovered from any radiotherapy related acute toxicities.
5. Presence of measurable disease as defined by the RECIST version 1.1

Cohort 2: Patient Population: Relapsed/Refractory Soft Tissue Sarcoma or Non-Kit GIST

1. Histologically confirmed diagnosis of advanced, unresectable, or metastatic soft tissue sarcoma not amenable to curative treatment with surgery or radiotherapy excluding:

   chondrosarcoma, neuroblastoma, osteosarcoma, embryonal rhabdomyosarcoma, or Kaposi sarcoma.

2. Must have received at least one prior line chemotherapy regimen and no other standard therapy with proven clinical benefit is available.
3. The disease should be progressing/relapsed during or after the previous treatment. At least 3 weeks should have elapsed since prior chemotherapy or 5 half-lives, whichever is shorter, as long as the patient recovered from any related toxicities to ≤ Grade 1.
4. Presence of measurable disease as defined by RECIST version 1.1

Cohort 3: Patient Population: Relapsed/Refractory Triple Negative Breast Cancer

1. Histologically or cytologically confirmed locally advanced or metastatic Triple Negative Breast Cancer.
2. Must have received at least one line of chemotherapy and no other standard therapy with proven clinical benefit is available. At least 3 weeks should have Elapsed since prior chemotherapy or 5 half-lives, whichever is shorter, as long as the patient recovered from acute toxicity of previous therapies to ≤ grade 1.
3. Prior radiotherapy is acceptable provided it was applied within 4 four weeks before starting of this trial and the patient recovered from any radiotherapy related acute toxicities.
4. The disease should be progressing/relapsed during or after the previous treatment.
5. Presence of measurable disease as defined by RECIST version 1.1

Cohort 4: Patient Population: Relapsed/Refractory Ovarian Cancer

1. Histologically or cytologically confirmed advanced ovarian cancer: epithelial ovarian cancer, primary peritoneal cancer or fallopian tube cancer (excluding borderline ovarian cancer) that is resistant or refractory to platinum therapy and no other standard therapy with proven clinical benefit is available.

   1. Platinum-resistant ovarian cancer is defined as disease that responded to primary platinum therapy and then progressed within 6 months or disease that progressed during or within six months of completing a subsequent platinum therapy.
   2. Primary platinum refractory disease is defined as disease that has not responded to a platinum-based regimen or experienced disease recurrence within 3 months of completing a first-line platinum-based regimen.
2. The disease should be progressing/relapsed during or after the previous treatment. At least 3 weeks should have elapsed since prior chemotherapy or 5 half-lives, whichever is shorter, as long as the patient recovered from acute toxicity of previous therapies to ≤ Grade 1.
3. Presence of measurable disease as defined by RECIST version 1.1