Slow Accrual

The goal of Part 1 of this clinical research study is to learn about the safety of the combination of plerixafor and clofarabine when given to patients with previously untreated AML who are at least 60 years old.

The goal of Part 2 of this study is to learn if the combination of plerixafor and clofarabine can help to control previously untreated AML in patients who are at least 60 years old. Study was closed early and did not progress to Part 2.

The Study Drugs:

Plerixafor is designed to block a protein on cancer cells from attaching to cells in the bone marrow. This may allow cells in the bone marrow to be more effectively treated by chemotherapy.

Clofarabine is designed to interfere with the growth and development of cancer cells.

Study Groups:

If you are found to be eligible to take part in this study, you will be assigned to a study group based on when you joined this study. Up to 3 groups of up to 6 participants will be enrolled in the Part 1 portion of the study, and up to 48 participants will be enrolled in Part 2.

If you are enrolled in Part 1, the dose of plerixafor you receive will depend on when you joined this study. The first group of participants will receive the lowest dose level of plerixafor. Each new group will receive a higher dose of plerixafor than the group before it, if no intolerable side effects were seen.

If you are enrolled in Part 2, you will receive plerixafor at the highest dose that was tolerated in Part 1.

All participants will receive the same doses of clofarabine.

Study Drug Administration:

Cycles in this study are 28 days long, or possibly longer depending on your blood counts, any side effects, and the status of the disease.

On Days 1-5 of each cycle, you will receive plerixafor through a needle under the skin of your abdomen.

On Days 1-5 of each cycle, you will receive clofarabine by vein over about 1 hour. The dose will begin about 4 to 6 hours after the plerixafor injection. You will be watched for side effects while you receive clofarabine.

If the doctor thinks it is in your best interest, the dose level of plerixafor may be lowered.

Cycle 1 is called Induction. If the disease goes into remission (responds well) after the Induction cycle, you will start the Consolidation part of the study. In the Consolidation cycles, the schedule of administration of the drugs will be the same as in the Induction cycle, but the doses of clofarabine will be lower. If the disease does not go into remission after the Induction cycle, you will have a Reinduction cycle before you can begin the Consolidation part of the study. The goal of the Induction cycle and possible Reinduction cycle is to affect the bone marrow a certain way that may help control the disease. The goal of Consolidation is also to help control the disease.

Study Visits:

Induction (Cycle 1):

On Day 1 of Induction, blood (about ½ tablespoon each time) will be drawn for routine tests before the plerixafor injection and 3 times during the 8 hours after the injection.

On Days 2-5 of Induction, blood (about ½ tablespoon each time) will be drawn for routine tests before the plerixafor injection and again at 8 hours after the injection.

Starting in Week 2 of Induction, blood (about 2 tablespoons) will be drawn at least 2 times a week for routine tests.

You will have a bone marrow aspiration and/or biopsy to check the status of the disease on Day 21 of Induction and every 2 weeks after that, until the Induction cycle is over.

Reinduction:

If you have a Reinduction cycle, blood (about 2 tablespoons) will be drawn at least 2 times a week during Reinduction for routine tests. You will have a bone marrow aspiration and/or biopsy to check the status of the disease on Day 21 of Reinduction and every 2 weeks after that, until the Reinduction cycle is over.

Consolidation:

Blood (about 2 tablespoons) will be drawn 1 time a day for routine tests on Days 1-5 of Consolidation.

Starting in Week 2 of each Consolidation cycle, blood (about 2 tablespoons) will be drawn for routine tests every week for the rest of each Consolidation cycle.

You will have a bone marrow aspiration and/or biopsy to check the status of the disease anytime during Consolidation that the doctor decides it is needed.

Induction, Reinduction, and Consolidation:

The blood tests and/or bone marrow aspirations/biopsies may be performed more often than listed if the doctor thinks it is needed. Also, you will have an ECG anytime during the study if the doctor thinks it is needed.

Length of Study:

You may continue taking the study drugs for up to 5 Consolidation cycles, if the doctor thinks it is in your best interest. You will no longer be able to take the study drugs if the disease gets worse or intolerable side effects occur.

Your participation on the study will be over once you have completed the follow-up visits.

Follow-Up Visits:

At 1 and 3 months after you stop taking the study drugs:

• Blood (about 2 tablespoon) will be drawn for routine tests.
• If the doctor decides it is needed, you will have a bone marrow aspiration to check the status of the disease.

If the disease responds (if it goes into complete or partial remission), you will have follow-up visits every 3 months for up to 2 years after you stop taking the study drugs. The follow-up visits will stop if the disease gets worse, or if you start a new cancer therapy and the disease has not gotten worse. The following tests and procedures will be performed at the follow-up visits:

• Blood (about 2 tablespoon) will be drawn for routine tests.
• If the doctor decides it is needed, you will have a bone marrow aspiration to check the status of the disease.

This is an investigational study. Clofarabine is FDA approved and commercially available to treat acute lymphoblastic leukemia (ALL) in children after the disease has gotten worse a second time. Plerixafor is FDA approved to be given with G-CSF and is commercially available for use in moving stem cells into the bloodstream before a stem cell transplant to treat non-Hodgkin's lymphoma or multiple myeloma. The combination of clofarabine and plerixafor is investigational.

Up to 66 patients will take part in this study. All will be enrolled at MD Anderson.

Inclusion Criteria:

1. Age >/= 60 years
2. Diagnosis of untreated AML (de novo, secondary, or with an antecedent hematologic disorder [AHD]) according to the World Health Organization (WHO) criteria
3. Eastern Cooperative Oncology Group (ECOG) performance status 0-2.
4. At least 2 of the following adverse prognostic factors: Age >/= 70 years; or AHD; or ECOG performance status of = 2; or intermediate or unfavorable (ie, adverse) karyotype defined as any cytogenetic profile except the presence of any of the following: t(8;21)(q22;q22), inv(16)(p13q22) or t(16;16)(p13;q22), t(15;17)(q22;q12) and variants.
5. Provide signed, written informed consent.
6. Be able to comply with study procedures and follow-up examinations.
7. Adequate renal and hepatic function as indicated by all of the following: Total bilirubin </=1.5 x institutional Upper Limit of Normal (ULN); an Aspartate Aminotransferase (AST) or Alanine Aminotransferase (ALT) </=2.5 x Upper limits of normal (ULN); and an estimated creatinine clearance (CrCl) of > 50 mL/min, as calculated by the Cockcroft -Gault equation.
8. Adequate cardiac function as measured by at least 1 of the following: Left ventricular ejection fraction (LVEF) >/=40% on multigated acquisition (MUGA) scan or similar radionuclide angiographic scan; or Left ventricular fractional fractional shortening >/=22% on echocardiography exam; or LVEF >/=40% on echocardiography exam.
9. Women of child-bearing potential (WOCBP) must agree to use adequate birth control through the end of the last treatment visit. WOCBP is a women who has not been naturally postmenopausal for at least 12 consecutive months or who had not undergone previous surgical sterilization.

Exclusion Criteria:

1. Diagnosis of acute promyelocytic leukemia (APL), (French-American-British classification M3 or WHO classification of APL with t(15;17)(q22;q12), (PML/RAR alpha fusion gene and variants).
2. Prior treatment with clofarabine.
3. Prior treatment for AML or an AHD (excluding supportive care, hydroxyurea, hematopoietic cytokines, or lenalidomide [the latter specifically for an AHD only]). Hematopoietic cytokines and lenalidomide must not have been received within 14 days prior to first dose of study drug; hydroxyurea is allowed on study to control white blood cell count (WBC) counts. If any of the above treatments have been received for AML or an AHD within the permissible time periods, drug-related toxicities must have recovered to Grade 1 or less prior to first dose of study drug.
4. Prior hematopoietic stem cell transplant (HSCT).
5. Prior external beam radiation therapy to the pelvis.
6. Investigational agent received within 30 days prior to the first dose of study drug. If received any investigational agent prior to this time point, drug-related toxicities must have recovered to Grade 1 or less prior to first dose of study drug.
7. Systemic fungal, bacterial, viral, or other infection not controlled (defined as exhibiting ongoing signs/symptoms related to the infection and without improvement, despite appropriate antibiotics or other treatment).
8. Any other severe concurrent disease, or have a history of serious organ dysfunction or disease involving the heart, kidney, liver or other organ system that may place the patient at undue risk to undergo therapy with clofarabine.
9. Clinical evidence suggestive of central nervous system (CNS) involvement with leukemia unless a lumbar puncture confirms the absence of leukemic blasts in the cerebrospinal fluid (CSF)
10. Prior positive test for the human immunodeficiency virus (HIV).
11. WBC >50 × 10^9/L; the first 3 patients enrolled on the study will be required to have a WBC of <20 × 10^9/L.
12. Have psychiatric disorders that would interfere with consent, study participation, or follow-up.
13. Have been diagnosed with another malignancy, unless the patient has been disease free for at least 5 years following curative intent therapy, following exceptions: Patients with treated nonmelanoma skin cancer, in situ carcinoma, or cervical intraepithelial neoplasia, regardless of disease-free duration, if definitive treatment for the condition has been completed or patients with organ-confined prostate cancer with no evidence of recurrent or progressive disease based on prostate-specific antigen (PSA) values if hormonal therapy has been initiated or radical prostatectomy has been performed.
14. Are pregnant or lactating.

Adverse event data collected during 28-day cycle, up to 6 cycles (24 weeks).

Early termination led to no subjects analyzed for later period outcomes.