This is a Phase 1 study during which patients with low or intermediate-1 risk myelodysplastic syndrome (MDS) will receive investigational study drug ARRY-614.

This study has 2 parts. In the first part, patients will receive increasing doses of study drug, given either with food or without food, in order to achieve the highest dose of the study drug possible that will not cause unacceptable side effects. Approximately 60 patients from the US will be enrolled in Part 1 (Completed).

In the second part of this study, patients will receive the best dose of study drug, given either with food or without food, determined from the first part of the study and will be followed to see what side effects and effectiveness the study drug has, if any, in treating the cancer. Approximately 40 patients from the US will be enrolled in Part 2 (Completed).

Key Inclusion Criteria (Part 1 and Part 2):

• Diagnosis of MDS by bone marrow biopsy.
• International Prognostic Scoring System (IPSS) score of low or intermediate-1 risk MDS.
• May have received prior therapy for MDS.
• Eastern Cooperative Oncology Group (ECOG) performance status (PS) between 0 and 2.
• Adequate liver and renal function.
• Additional criteria exist.

Key Exclusion Criteria (Part 1 and Part 2):

• History of bone marrow transplant.
• Concomitant malignancies or previous malignancies with less than a 2-year disease-free interval at the time of enrollment.
• Treatment with an investigational medicinal product that is not expected to be cleared by the first dose of study drug or that has demonstrated to have late side effects.
• Known positive serology for the human immunodeficiency virus (HIV), hepatitis C and/or active hepatitis B.
• Additional criteria exist.