Study of the Safety, Pharmacokinetics and Efficacy of EDO-S101, in Patients With Advanced Solid Tumors

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 or recommended based on the
   investigator's individual risk-benefit as-sessment for the patient.

   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 or recommended based on the investigator's individual
   risk-benefit assessment for the patient.

   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 (or ≤ Grade 2 for any symptomatic neuropathy or endocrinopathies).

   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

   1. Histologically confirmed diagnosis of advanced, unresectable, or metastatic soft
   tissue sarcoma not amenable to curative treatment with surgery or radiotherapy
   excluding: neuroblastoma, 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 or recommended based on the
   investigator's individual risk-benefit assessment for the patient. For GIST-patients:
   must have received at least two lines of tyrosine kinase inhibitors or do not respond
   to or for which tyrosine kinase inhibitor therapy is not suitable.

   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
   (or ≤ Grade 2 for any symptomatic neuropathy or endocrinopathies).

   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. Proven HER2 negative by immunohistochemistry (IHC) or in situ
   hybridization (ISH) per ASCO-CAP guidelines.

   2. Must have received at least one line of chemotherapy and no other standard therapy
   with proven clinical benefit is available or recommended based on the investigator's
   individual risk-benefit assessment for the patient. 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 (or ≤ Grade 2
   for any symptomatic neuropathy or endocrinopathies).

   3. Prior radiotherapy is acceptable provided it was applied within 4 four weeks (2 weeks
   for palliative, limited field radiation therapy) prior to starting treatment on 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 or recommended based on the
   investigator's individual risk-benefit assessment for the patient.

      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 (or ≤ Grade 2 for any symptomatic neuropathy or endocrinopathies).

   3. Presence of measurable disease as defined by RECIST version 1.1

Cohort 5: Relapsed/Refractory Endometrial Cancer

   1. Histologically or cytologically confirmed locally advanced or metastatic endometrial
   cancer.

   2. Must have received at least one line of chemotherapy and no other standard therapy
   with proven clinical benefit is available or recommended based on the investigator's
   individual risk-benefit assessment for the patient. 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 (or ≤ Grade 2
   for any symptomatic neuropathy or endocrinopathies).

   3. Prior radiotherapy is acceptable provided it was administered at least 4 weeks (2
   weeks for palliative, limited field radiation therapy) prior to starting treatment on
   this trial and 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.