Safety, Efficacy and Pharmacokinetic Study of PRLX 93936 in Patients With Multiple Myeloma

Inclusion Criteria:

* Patient must have a diagnosis of multiple myeloma and have relapsed or relapsed/refractory disease.
* Patient must have received ≥ 2 prior anti-myeloma regimens including a proteasome inhibitor and/or immunomodulatory agent.
* Patient currently requires systemic therapy.
* Patient has measurable disease.
* Age ≥ 18 years
* Karnofsky performance status ≥ 60%
* ECOG performance 0, 1 or 2
* Life expectancy of at least three months
* Able to take acetaminophen
* Not pregnant
* Patient must have recovered from toxicities incurred as a result of any previous anti-myeloma therapy or recovered to baseline.
* Patients who received an autologous stem cell transplant must be ≥ 3 months post-transplant and all associated toxicities must have resolved to ≤ CTCAE Grade 1.
* QT intervals of QTc ≤ 500 msec

Exclusion Criteria:

* POEMS syndrome
* Plasma cell leukemia
* Primary amyloidosis
* Patient has smoldering multiple myeloma or monoclonal gammopathy of unknown significance (MGUS).
* Evidence of spinal cord compression or CNS complication unless controlled by appropriate therapy.
* Patient received chemotherapy or other anti-cancer therapy that may be active against multiple myeloma within 3 weeks prior to the first dose of PRLX 93936.
* Patient received nitrosureas within 6 weeks prior to the first dose.
* Patient received corticosteroids within 2 weeks prior to the first dose.
* Patient received plasmapheresis within 4 weeks prior to the first dose.
* Patient had major surgery within 4 weeks prior to the first dose.
* Patient had an allogeneic stem cell transplant within 6 months before first dose of PRLX 93936 or has evidence of graft versus host disease.
* Patient is taking any therapy concomitantly that may be active against multiple myeloma.
* Patient is currently receiving medication(s) that are principally metabolized via the cytochrome P450 3A4 enzyme pathway.
* Use of any investigational agents within 28 days or 5 half-lives (whichever is shorter) of study treatment.
* Patient has peripheral neuropathy of Grade 3 or greater intensity, or painful Grade 2, as defined by the NCI CTC.
* Patient had a myocardial infarction within 6 months of enrollment or has NYHA Class III or IV heart failure uncontrolled angina, severe uncontrolled ventricular arrhythmias, or electrocardiographic evidence of acute ischemia or active conduction system abnormalities.
* Abnormal LVEF (\< LLN for the institution for a patient of that age) on echocardiogram
* Patient has poorly controlled hypertension, diabetes mellitus, or other serious medical or psychiatric illness that could potentially interfere with the completion of treatment according to protocol.
* Patient had a malignancy other than multiple myeloma within 3 years before enrollment, with the exception of adequately treated basal cell or squamous cell skin cancer, in situ cervical cancer, in situ breast cancer, or in situ prostate cancer.
* Patient's clinical laboratory values meet any of the following criteria within the 7 days prior to Study Day 1:

  * Bilirubin \> 1.5 times ULN
  * AST (SGOT), ALT (SGPT) and Alkaline phosphatase \> 2.5 times ULN
  * Uncontrolled hypercalcemia (defined as serum calcium \> 14 mg/dL)
  * Serum creatinine \> 2.0 mg/dL or creatinine clearance of \< 30 mL/min
  * ANC \< 1000 cells/mm3 or \< 750 cells/mm3 due to \>50% marrow involvement
  * Platelet count \< 50,000 cells/mm3
  * Hemoglobin \< 8.0 g/dL
* Patient is known to be human immunodeficiency virus (HIV)-positive.
* Patient is known to be hepatitis B surface antigen-positive or has known active hepatitis C infection.
* Patient has an active systemic infection requiring treatment or within 14 days before first dose of PRLX 93936.
* Pregnant or nursing women