Phase I study will evaluate the effect of tipifarnib on cardiac repolarization (corrected QT interval \[QTc\] duration) following a single dose of 900 mg and after repeated twice daily administration of 600 mg in subjects with advanced solid malignancies. The study will enroll approximately 20 subjects with advanced solid malignancies (at least 8, but no more than 12, male subjects). Subjects must have no approved/appropriate therapeutic options available. Subject will undergo series of ECG at Cycle 1 day -1 follow by study drug dosing, series of Pharmacokinetic and ECG at Cycle 1 day 1 and Cycle 1 day 7. Beginning on Day 2 of Cycle 1, subjects will self-administer 600 mg tipifarnib, orally with a meal, bid for 7 days in alternating weeks (Days 2-7 and 15-21) in 28-day cycles. For Cycle 2 and beyond, subjects will self-administer 600 mg bid on Days 1-7 and Days 15-21 in 28-day cycles.