Due to slow enrollment, the extensive time projected to conclude the study hypothesis rendered the study no longer reasonably feasible to complete.

The purpose of this two-stage Phase 2 study is to assess the clinical response (Complete Remission) of ACM (Alvocidib/Cytarabine/Mitoxantrone) compared to CM (Cytarabine/Mitoxantrone) treatment in refractory or relapsed AML patients with demonstrated MCL-1 dependence of ≥ 30% by mitochondrial profiling in bone marrow.

In Stage 1 of the study, all eligible AML patients with demonstrated MCL-1 dependence of ≥ 30% by mitochondrial profiling in bone marrow will receive treatment with ACM.

In Stage 2, all eligible AML patients with demonstrated MCL-1 dependence of ≥ 30% by mitochondrial profiling in bone marrow will be randomized 1:1 to receive either treatment with ACM or CM.

Inclusion Criteria:

1. Be between the ages of ≥18 and ≤65 years

2. Have an established, pathologically confirmed diagnoses of AML by World Health Organization (WHO) criteria excluding acute promyelocytic leukemia (APL-M3) with a bone marrow of >5% blasts based on histology or flow cytometry

3. Be in first relapse (within 24 months of CR) or have failed induction therapy* (no CR or CRi after treatment with an intensive regimen (eg, anthracycline/cytarabine ± etoposide, gemtuzumab ozogamicin, or cladribine).

   *Induction therapy may involve 1 or 2 cycles of the same regimen. Efficacy assessment of induction therapy must be >21 days from the start of the previous induction cycle.

4. Demonstrate MCL-1 dependence of ≥30% by mitochondrial profiling in bone marrow.

5. Have an Eastern Cooperative Oncology Group (ECOG) performance status (PS) ≤2

6. Have a serum creatinine level ≤1.8 mg/dL

7. Have an alanine aminotransferase (ALT)/aspartate aminotransferase (AST) level ≤5 times upper limit of normal (ULN)

8. Have a total bilirubin level ≤2.0 mg/dL (unless secondary to Gilbert syndrome, hemolysis, or leukemia)

9. Have a left ventricular ejection fraction (LVEF) >45% by echocardiogram (ECHO) or multigated acquisition (MUGA) scan

10. Be nonfertile or agree to use an adequate method of contraception. Sexually active patients and their partners must use an effective method of contraception associated with a low failure rate during and for at least 6 months after completion of study therapy.

11. Be able to comply with the requirements of the entire study.

12. Provide written informed consent prior to any study related procedure.

Exclusion Criteria:

1. Received more than 2 cycles of induction therapy for AML. Investigational agents as part of front-line therapy for AML may by acceptable following discussion with the Medical Monitor. Hydroxyurea is permitted (see #5 below).
2. Received any previous treatment with alvocidib or any other CDK inhibitor
3. Received a hematopoietic stem cell transplant within the previous 2 months
4. Have clinically significant graft versus host disease (GVHD), or GVHD requiring initiation or escalation of treatment within the last 21 days
5. Require concomitant chemotherapy, radiation therapy, or immunotherapy. Hydroxyurea is allowed up to the evening before starting (but not within 12 hours) of starting treatment on either arm.
6. Received >360 mg/m2 equivalents of daunorubicin
7. Have a peripheral blast count of >30,000/mm3 (may use hydroxyurea as in #5 above)
8. Received antileukemic therapy within the last 3 weeks (with the exception of hydroxyurea or if the patient has definite refractory disease). Refractory patients who received therapy within the last 3 weeks may be eligible with prior approval of the Medical Monitor.
9. Diagnosed with acute promyelocytic leukemia (APL, M3)
10. Have active central nervous system (CNS) leukemia
11. Have evidence of uncontrolled disseminated intravascular coagulation
12. Have an active, uncontrolled infection
13. Have other life-threatening illness
14. Have other active malignancies or diagnosed with other malignancies within the last 6 months, except nonmelanoma skin cancer or cervical intraepithelial neoplasia
15. Have mental deficits and/or psychiatric history that may compromise the ability to give written informed consent or to comply with the study protocol.
16. Are pregnant and/or nursing
17. Have received any live vaccine within 14 days prior to first study drug administration.