Background: Treatment results in patients with metastatic renal cell cancer (RCC) are still extremely unsatisfactory. Rates of response to IFN-alpha monotherapy and/or IL-2 mono/combination therapy vary between 10% and 20%. Coumarin (Cum) together with cimetidine (Cim) has yielded objective responses in 20%-33% of patients with RCC, according to two recent phase II studies.
Patients and methods: In the present study 148 patients with metastatic RCC were randomised to receive either IFN-alpha (5 MU 5 x weekly s.c.) + coumarin (100 mg/d p.o.) + cimetidine (3 x 400 mg/d p.o.), or IFN-alpha-monotherapy (5 MU 5 x weekly s.c.).
Results: Of the 148 patients in the study 137 were evaluable for response. No differences in remission rates (RR IFN-alpha + Cum + Cim 17.1% and IFN-alpha 20.8%) or survival times (median survival 9 months and 8 months, respectively) were found between these two treatment arms.
Conclusions: This study confirms that INFN-alpha has antitumoral activity in RCC. Adding coumarin + cimetidine to IFN-alpha in the dose and regimen prescribed in this study did not increase response rates or survival.