A Phase I Trial of Dose Escalating Simvastatin Combined with Chemotherapy in End-Stage Myeloma and Lymphoma.

We recently described that simvastatin effectively induced apoptosis in myeloma and lymphoma tumor cells by inhibition of proteingeranylgeranylation resulting in the reduction of the anti-apoptosis protein Mcl-1. In addition low concentrations of simvastatin had a chemosensitizing effect in combination with dexamethasone or doxorubicin. Based on these observations we initiated a Phase I study of dose escalating simvastatin combined with chemotherapy in patients with end-stage Myeloma and Lymphoma. Starting dose level of simvastatin was 5 mg/kg/day for 7 days, divided in 2 doses orally, followed by VAD chemotherapy in patients with myeloma and CHOP in patients with lymphoma. Three patients were included per dose level. In the absence of side effects WHO grade III/IV in 3 patients the dose of simvastatin was escalated with 2.5 mg/kg. Twenty-one heavily pretreated patients all refractory to at least 3 lines of chemotherapy (14 myeloma patients and 7 lymphoma patients) were included. No toxicity beyond WHO 2 was recorded with dose level 1–4 (5 mg–12.5mg/kg/day/7days). One patient treated at dose level 5 (15 mg simva/kg/day/7 days) became severely depressed and performed an unsuccessful suicide attempt. Two patients treated at dose level 6 (17.5 mg/kg/day/7 days had severe gastro-intestinal side effects (WHO 3; vomiting, diarrhoea, dehydration), necessitating interrupting simvastatin after 3 and 4 day respectively. The third patient treated at dose level 6 had moderate gastro-intestinal complaints but died on day 13 (2 days after VAD, deeply neutropenic) from overwhelming Gram-Septicaemia although prophylactic antibiotics had been prescribed. Three additional patients were then treated at dose level 5 again without side effects beyond WHO 2. None of the patients complained about muscle pain. No signs of rhabdomyolysis were registered.

Although response was not the primary endpoint of the study, it could be evaluated in 16 patients who completed at least 2 cycles of simvastatin with chemotherapy. Six patients (4 myeloma and 1 transformed low grade lymphoma) responded (32 %) including 5 patients with a Partial Response (> 50 tumor reduction) and 1 patient with a minor response. Four of 8 evaluable (myeloma) patients treated at dose level 4 and 5 responded. Due to toxicity all 3 patients at dose level 6 were not evaluable for response. In patients treated at dose level 4 and 5, in vivo down regulation of Mcl-1 (> 50 %) was observed in PBMC collected after 7 days of simvastatin treatment. These data show that in vivo downregulation of Mcl-1 by high dose (simva) statin in combination with chemotherpy may be a promising new modality for patients with drug resistant myeloma and lymphoma.