Tipifarnib in Subjects With Chronic Myelomonocytic Leukemia, Other MDS/MPN, and Acute Myeloid Leukemia

This Phase 2 study will investigate the antitumor activity in terms of ORR of tipifarnib in subjects with Myelodysplastic/Myeloproliferative Neoplasias (MDS/MPN cohorts) and Acute Myeloid Leukemia (AML cohorts). For MDS/MPN cohorts, this study will assess the antitumor activity of tipifarnib, in terms of ORR, in subjects with MDS/MPN, including CMML, who have a high ratio of expression of CXCR4 to CXCR2 (CXCR4/2 ratio) in their bone marrow and in those with a low CXCR4/2 ratio. For AML cohorts, this study will assess the antitumor activity of tipifarnib, in terms of ORR, in subjects with AML who have a high ratio of expression of CXCR4 to CXCR2 (CXCR4/2 ratio) in their bone marrow and in those with low CXCR4/2 ratio. Subjects enrolled in the study will consist of patients with KRAS, NRAS wild type status. 1. Subjects with MDS/MPN with high CXCR4/2 ratio 2. Subjects with MDS/MPN with low CXCR4/2 ratio 3. Subjects with AML with high CXCR4/2 ratio 4. Subjects with AML with low CXCR4/2 ratio