In vitro statins induce apoptosis in myeloma and lymphoma cells in a dose-and time-dependent way. In combination with dexamethasone and doxorubicin, statins have a chemo-sensitizing effect. Twenty-eight patients with relapsed myeloma or lymphoma were treated with a dose-escalating regimen of simvastatin for 7 days followed by VAD in myeloma patients and CHOP in lymphoma patients. The maximum tolerated dose was 15 mg/kg/day simvastatin. The most frequently reported side-effects were fatigue, gastrointestinal CTC grade 1-2 and neutropenic fever. The dose-limiting toxicity was neutropenic sepsis and grade 3 gastrointestinal side effects. High-dose simvastatin given immediately prior to chemotherapy is safe and tolerable up to a dose of 15 mg/kg/day.