Study of Vosaroxin or Placebo in Combination With Cytarabine in Patients With First Relapsed or Refractory AML

Inclusion Criteria:

* Provided signed, written informed consent
* At least 18 years of age
* Had a diagnosis of AML according to World Health Organization (WHO) classification
* First relapsed or refractory AML (refractory to initial induction therapy) with at least 5% blasts by bone marrow or aspirate or 1% blasts in peripheral blood with additional requirements for relapsed or refractory
* Had an ECOG score of 0-2
* Had adequate liver and renal function as indicated by certain laboratory values
* Had adequate cardiac function (left ventricular ejection fraction at least 40% by multiple gated acquisition scan or ECG)
* Nonfertile or agreed to use an adequate method of contraception until 30 days after the last treatment
* Had any clinically significant nonhematologic toxicity after prior chemotherapy recovered to Grade 1 per NCI-CTCAE

Exclusion Criteria:

* Had acute promyelocytic leukemia
* Had more than 2 cycles of induction therapy for AML
* Had completed a single cycle of treatment containing a total dose of 5 g/m2 or more of cytarabine within 90 days before randomization
* Refractory to or relapsed within the previous 3 months after therapy with an IDAC- or HIDAC-containing regimen
* Had received a hematopoietic stem cell transplant (HSCT) within the previous 90 days
* Had received active immunosuppressive therapy for graft-versus-host disease (GVHD) within 2 weeks before study start
* Had any other severe concurrent disease, or have a history of serious disease involving the heart, kidney, liver, or other organ system
* Had evidence of central nervous system involvement of active AML
* Had other active malignancies (including other hematologic malignancies) or been diagnosed with other malignancies within the last 12 months, except nonmelanoma skin cancer or cervical intraepithelial neoplasia
* Had an active, uncontrolled infection
* Had received any other investigational therapy within 14 days or not recovered from acute affects of the other investigational therapy
* Had received prior or current hydroxyurea or medications to reduce blast count within 24 hours before randomization
* Had received previous treatment with vosaroxin
* Pregnant or lactating
* Had any other medical, psychological, or social condition that may interfere with consent, study participation, or follow-up
* Had known HIV seropositivity