This is a two-arm, open-label study to determine the maximum tolerated dose (MTD) and assess the safety, pharmacokinetics, pharmacodynamics, and preliminary efficacy of BMN 673 in patients with Acute Myeloid Leukemia (AML), Myelodysplastic Syndrome (MDS), Chronic Lymphocytic Leukemia (CLL) and Mantle Cell Lymphoma (MCL). Arm 1 will enroll patients with either AML or MDS; Arm 2 will enroll patients with either CLL or MCL.

Inclusion Criteria:

1. 18 years of age or older.

2. Eastern Cooperative Oncology Group (ECOG) performance status ≤ 1

3. Arm 1 AML/MDS: Must have available tissue

4. Arm 2 CLL/MCL: Must have available tissue

5. Have adequate organ function as defined below:

   1. Serum aspartate aminotransferase (AST)/alanine aminotransferase (ALT) ≤ 2.5 X upper limit of normal (ULN);
   2. Total serum bilirubin ≤ 1.5 X ULN;

6. Able to take oral medications

7. Recovered from acute toxicity of prior treatment

8. Willing and able to provide written, signed informed consent after the nature of the study has been explained, and prior to any research-related procedures.

9. If sexually active, must be willing to use an acceptable method of contraception during therapy and for 30 days after the last dose of BMN 673.

10. If female of childbearing potential, must have a negative serum pregnancy test at screening and be willing to have additional pregnancy tests during the study.

11. Willing and able to comply with all study procedures.

Exclusion Criteria:

1. Acute promyelocytic leukemia, APL [AML with t(15;17)(q22;q12), PML-RARA and variants].

2. Disease-specific exclusion criteria:

   a. AML: i. Marrow cellularity < 25% ii. Circulating blasts > 50,000/mm3 b. MCL and CLL: i. Platelet count < 50,000/mm3 ii. Neutrophil count < 1000/mm3

3. Autologous bone marrow transplant < 6 months before Cycle 1 Day 1

4. Prior allogeneic bone marrow transplant < 6 months before Cycle 1 Day 1 and/or with the presence of graft versus host disease (GVHD)

5. Prior treatment:

   1. AML: anti-leukemia treatment within 14 days before Cycle 1 Day 1; hydroxyurea treatment within 7 days before Cycle 1 Day 1.
   2. CLL, MCL or MDS: anti-lymphoma/leukemia treatment within 28 days before Cycle 1 Day 1;

6. CLL/MCL patients who have received transfusion, hematopoietic growth factors within 7 days before Cycle 1 Day 1.

7. Symptomatic central nervous system (CNS) involvement.

8. Known to have human immunodeficiency virus (HIV) or active hepatitis C virus (HCV) or hepatitis B virus (HBV).

9. Major surgery within 28 days before Cycle 1, Day 1.

10. Active peptic ulcer disease.

11. Active gastrointestinal tract disease with malabsorption syndrome.

12. Requirement for IV alimentation.

13. Prior surgical procedures affecting absorption.

14. Uncontrolled inflammatory bowel disease (eg, Crohn's disease, ulcerative colitis).

15. Myocardial infarction within 6 months before Cycle 1 Day 1, symptomatic congestive heart failure (New York Heart Association > class II), unstable angina, or unstable cardiac arrhythmia requiring medication.

16. Breastfeeding at screening or planning to become pregnant (self or partner) at any time during study participation.

17. Use of any investigational product or investigational medical device within 28 days before Cycle 1, Day 1.

18. Concurrent disease or condition that would interfere with study participation or safety, such as:

    1. CLL/MCL patients with active, clinically significant infection requiring the use of parenteral anti-microbial agents, or grade > 2 infection by NCI CTCAE (v4.03) within 14 days before Cycle 1, Day 1(AML/MDS patients with controlled infection are eligible for the study with no specific time requirement prior to Cycle 1, Day 1);
    2. Clinically significant bleeding diathesis or coagulopathy, including known platelet function disorders;
    3. Non-healing wound, ulcer, or bone fracture.

19. Patients who have received prior treatment with a PARP inhibitor are not eligible for Part 2 of the study (expansion), but are eligible for Part 1 (dose escalation) of the study.

Information relating to our policy on data sharing and the process for requesting data can be found at the following link: http://www.pfizer.com/research/clinical\_trials/trial\_data\_and\_results/data\_requests