A Phase I, Two-part Study to Determine the Recommended Dose and Evaluate the Safety and Tolerability of a Novel Oral Arsenic Trioxide Formulation (ORH-2014) in Subjects With Advanced Hematological Disorders

Inclusion Criteria:

* Female and male subjects ≥18 years of age with one of the following:

  * Relapsed or refractory acute myelocytic leukemia (AML) with nucleophosmin-1 (NPM1) mutations and no available therapies.
  * Relapsed or refractory acute promyelocytic leukemia (APL), with no available therapies. Note: Prior exposure to arsenic trioxide is allowed; however, subjects who have failed arsenic trioxide within the last 12 months are not allowed.
  * Relapsed or refractory myelodysplastic syndrome (MDS), International Prognostic Scoring System intermediate or high-risk, with no available therapies
  * Relapsed or refractory chronic myelomonocytic leukemia (CMML), and other MDS/myeloproliferative neoplasm (MPN) overlap syndromes, with no available therapies
  * Relapsed or refractory mantle cell lymphoma (MCL) with no adequate therapies.
* Negative pregnancy test at the Screening visit for women of childbearing potential and willingness to use adequate birth control
* Not willing to undergo, not a candidate for, or not having a donor for immediate (within 3 months from the Screening date) bone marrow transplantation.

Exclusion Criteria:

* Eastern Cooperative Oncology Group performance status of ≥3;
* Absolute myeloblast count ≥20,000/mm\^3;
* Administration of any antineoplastic therapy within 5 half-lives of the antineoplastic therapy before the first dose of ORH-2014, with the exception of hydroxyurea that should be discontinued 1 day prior to the first dose of ORH-2014
* Presence of any remaining toxicities due to previous chemotherapy
* Participation in other clinical trials within at least 2 weeks of the first ORH-2014 dose;
* Clinical evidence of active central nervous system leukemia;
* Active and uncontrolled infection
* Major surgery within 2 weeks prior to trial entry;
* Liver function tests above the following limits at Screening: total bilirubin \>1.5 x upper limit of normal (ULN) unless related to Gilbert's syndrome or hemolysis; aspartate aminotransferase (AST) and/or alanine aminotransferase (ALT) \>2.5 x ULN; for subjects with liver involvement, AST and/or ALT \>5 x ULN;
* Serum creatinine \>1.5 x ULN and/or creatinine clearance or estimated glomerular filtration rate \<30 mL/min
* Impaired cardiac function
* Myocardial infarction of unstable angina within 6 months prior to the planned start date of study drug.