Inclusion Criteria:

- Provide signed, written informed consent

- Are at least 18 years of age

- Have a diagnosis of AML according to World Health Organization (WHO) classification

- First relapsed or refractory AML (refractory to initial induction therapy)

- Have an ECOG score of 0-2

- Have adequate liver and renal function as indicated by certain laboratory values

- Are nonfertile or agree to use an adequate method of contraception until 30 days
after the last treatment

Exclusion Criteria:

- Have received more than 2 cycles of induction therapy for AML

- Refractory to or relapsed within the previous 3 months after therapy with an IDAC- or
HIDAC-containing regimen

- Have received a hematopoietic stem cell transplant (HSCT) within the previous 3
months

- Have received active immunosuppressive therapy for graft-versus-host disease (GVHD)
within 2 weeks before study start

- Have any other severe concurrent disease, or have a history of serious disease
involving the heart, kidney, liver, or other organ system

- Have evidence of central nervous system involvement of active AML

- Have 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

- Have an active, uncontrolled infection

- Are receiving any other investigational therapy

- Have received previous treatment with vosaroxin

- Are pregnant or lactating

- Have any other medical, psychological, or social condition that may interfere with
consent, study participation, or follow-up