Retrospective studies showed Sorafenib's efficacy as second line treatment after a TKI: AXIS study showed sorafenib activity, in terms of Overall Response Rate (ORR), and the absence statistically significant difference in Overall Survival (OS) between the 2 arms, although there is a significant OS increase of 1.4 months in the Axitinib arm. The INTORSECT study (temsirolimus vs sorafenib in 2nd line after sunitinib) didn't demonstrate statistically significant difference for Progression Free Survival (PFS), but it showed an OS increase in patients treated with sorafenib.~The COMPARZ study demonstrated the non-inferiority of pazopanib vs sunitinib in 1st line of treatment for mRCC.~Currently there is no standard of treatment in 2nd line for patients treated in first line with pazopanib for mRCC.~Primary objective:to evaluate the efficacy of sorafenib (PFS) as second line of treatment in patients treated with pazopanib for mRCC.~Secondary objectives: To evaluate the safety of sorafenib in patients previously treated with pazopanib. To evaluate the Overall Survival. To evaluate the Quality of Life through specific questionnaires (FKSI-19; European Organization for Research and Treatment of Cancer quality of life questionnaire -C30).To assess the predictive role for PFS and OS of arterial blood pressure increase from baseline to week 4 and 8 after start of treatment with sorafenib. To assess the predictive role for PFS and OS of hand-foot syndrome before week 4 and 8 after start of treatment with sorafenib.
Retrospective studies showed Sorafenib's efficacy as second line treatment after a Tyrosine Kinase Inhibitor (TKI).~Currently there is no standard of treatment in 2nd line for patients treated in first line with pazopanib for metastatic Renal Cell Carcinoma (mRCC).~With this trial we evaluate the efficacy of sorafenib as second line of treatment in patients treated with pazopanib for mRCC.