A Pivotal Randomized Study of Lonafarnib Versus Placebo in the Treatment of Subjects With Myelodysplastic Syndrome (MDS) or Chronic Myelomonocytic Leukemia (CMML) Who Are Platelet Transfusion Dependent With or Without Anemia

Inclusion Criteria:

- Confirmed MDS (RA, RARS, RAEB, RAEB-T) or CMML according to FAB classification.

- Platelet transfusion dependence (requiring 1 to 8 platelet transfusion events every 4
week period (Day 84 to Day 57, Day 56 to Day 29, and Day 28 to Day 1) over an
8-week retrospective and 4-week prospective screening period).

- The individual number of platelet transfusion events during the three 4-weekly
periods (Day 84 to Day -57; Day -56 to Day 29; Day -28 to Day -1) must not differ
by greater more than 2 from the average number of platelet transfusion events during
the 12 week screening period.

- If the subject is RBC transfusion dependent, the number of RBC transfusion events
during the three 4-weekly periods (Days -84 to -57; Day -56 to Day 29 and Day -28 to
Day -1) must not differ by more than 2 from the average number of RBC transfusion
events during this 12 week screening period.

ECOG PS 0-2.

Exclusion Criteria:

- Subjects with chemotherapy/radiotherapy-associated secondary MDS.

- <12 Weeks (prior to Day-1 Randomization) from any investigational drug use, any
chemotherapy, radiotherapy, immunotherapy and any other treatment or MDS/CMML other
than best supportive care.

- Hx of bone-marrow or peripheral stem-cell transplantation or treatment with donor
lymphocyte infusion.

- Hx of AML.

- Known hx of immune thrombocytopenic purpura.

- Marked baseline prolongation of QTc interval, CTCAE Grade >=1.

- Use of ketokonazole within 72 hours prior to study drug administration.