Oral ONC201 in Relapsed/Refractory Multiple Myeloma

This was a Phase 1/2 open-label study of ONC201 administered orally once every week in combination with dexamethasone in adults with relapsed/refractory multiple myeloma. The primary objective of this study was to evaluate the antitumor efficacy of ONC201.

Note: This study was completed by predecessor company, Oncoceutics, Inc.

In Phase 1 of the study, patients were to receive 375 or 625 mg ONC201 once every week in combination with dexamethasone using a 3+3 dose escalation design to evaluate up to 625 mg ONC201 weekly with 20 mg dexamethasone. In Phase 2 of the study, patients were to receive 625 mg ONC201 once every week. Dexamethasone was to be administered at a dose determined in Phase 1.

A treatment cycle was defined as 3 weeks. The dose-limiting toxicity window was defined as the first 3 weeks of treatment (i.e., 1 cycle). Patients may have continued treatment with ONC201 until disease progression, occurrence of an unacceptable adverse event, intercurrent illness or changes in the patient's condition rendered the patient unacceptable to continue, patient decision to withdraw from the study, or discontinuation of the study by the Sponsor.

Assessments of tumor response were conducted using the International Myeloma Working Group response criteria. Safety was assessed through the reporting of adverse events, measurement of vital signs, electrocardiograms, and clinical laboratory results.

Before the study was terminated, a total of 17 patients were enrolled and treated with ONC201: 2 patients received 375 mg ONC201 and 15 patients received 625 mg ONC201.

Eligibility Criteria:
Inclusion Criteria:

A patient had to meet all of the following criteria to be eligible to participate in the study:

1. Must have been refractory to, or not a candidate for, established therapy known to provide clinical benefit for their malignancy.
2. Had measurable disease M protein component in serum (at least 0.5 g/dL) and/or urine (if present) (≥0.2 g excreted in a 24 hour collection sample), or serum free light chain level ≥10 mg/dL, provided the serum free light chain ratio was abnormal.
3. Was able to swallow and retain oral medication.
4. Had all previous therapies for cancer, including radiotherapy, major surgery and investigational therapies discontinued for ≥14 days (≥28 days for mitomycin C or nitrosoureas) before study entry, and had all acute effects of any prior therapy resolved to baseline severity or Grade ≤1 Common Terminology Criteria for Adverse Events (CTCAE v4.03), except alopecia or parameters defined in this eligibility list.
5. Were aged ≥18 years.
6. Had an Eastern Cooperative Oncology Group (ECOG) performance status of ≤1.
7. Had adequate organ and marrow function as defined below:

   1. Absolute neutrophil count: ≥1,000/mm3 without growth factor use ≤7 days prior to treatment (cycle 1 day 1, C1D1)
   2. Platelets: ≥75,000/mm3 without platelet transfusion ≤3 days prior to C1D1
   3. Hemoglobin: 8.0 mg/dL without red blood cell transfusion ≤3 days prior to C1D1
   4. Total serum bilirubin: ≤1.5 X upper limit of normal (ULN)
   5. Aspartate aminotransferase (AST) (SGOT)/alanine aminotransferase (ALT) (SGPT): ≤2 X ULN; ≤ 5 X ULN if liver dysfunction was felt to be secondary to tumor burden
   6. Serum creatinine: ≤1.5 X ULN (OR creatinine clearance ≥30 mL/min/1.73 m2)
   7. Serum or urine pregnancy test (for females of childbearing potential) negative ≤7days of starting treatment
8. Had the ability to understand and the willingness to sign a written informed consent document and comply with the study scheduled visits, treatment plans, laboratory tests and other procedures.
9. Female patients must have been surgically sterile or be postmenopausal, or must have agreed to use effective contraception during the period of the trial and for at least 90 days after completion of treatment. Male patients must have been surgically sterile or must have agreed to use effective contraception during the period of the trial and for at least 90 days after completion of treatment. The decision of effective contraception was based on the judgment of the principal investigator or a designated associate.

Exclusion Criteria:

A potential patient who met any of the following criteria was ineligible to participate in the study:

1. Had active inflammatory gastrointestinal disease, chronic diarrhea (unless related to underlying malignancy or prior related treatment) or history of abdominal fistula, gastrointestinal perforation, peptic ulcer disease, or intra-abdominal abscess within 6 months prior to study enrollment. Gastroesophageal reflux disease under treatment with proton pump inhibitors was allowed.
2. Was pregnant or breast feeding.
3. Was undergoing current active treatment in another clinical study.
4. Had active bacterial, fungal or viral infection including hepatitis B (HBV), hepatitis C (HCV)
5. Had known human immunodeficiency virus (HIV) or acquired immunodeficiency syndrome (AIDS)-related illness that was not well controlled.
6. Had active or prior plasma cell leukemia (defined as either 20% of peripheral white blood cell count \[WBC\] comprised of plasma/CD138+ cells or an absolute count of 2x10\^9/L).
7. Had solitary bone or solitary extramedullary plasmacytoma as the only evidence of plasma cell dyscrasia.
8. Had serum calcium (corrected for albumin) ≥12 mg/dL
9. Had any of the following in the previous 6 months: myocardial infarction, severe/unstable angina, coronary/peripheral artery bypass graft, symptomatic congestive heart failure, cerebrovascular accident, transient ischemic attack or symptomatic pulmonary embolism.
10. Had other severe acute or chronic medical or psychiatric condition or laboratory abnormality that may have increased the risk associated with study participation or study drug administration, or may have interfered with the interpretation of study results, or in the judgment of the investigator would have made the patient inappropriate for entry into the study.