Validation of the International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) Prognostic Classification for Targeted Therapies (TKI/mTOR Inhibitors) in Second Line After First Line Treatment With Pazopanib

This is a nation-wide retrospective observational study which will be performed in 50 centres in Spain, geographically representative of all regions, with at least 5 patients treated with first-line pazopanib for mRCC in daily clinical practice since April 2011 (date of approval of pazopanib in Spain), January 2016.

Pazopanib is one of the standard tyrosine-kinase inhibitors (TKI) for the first-line treatment of metastatic renal cell carcinoma. In our previous SPAZO study, the Spanish Oncologic Genitourinary Group (SOGUG) validated the IMDC prognostic classification for patients receiving first-line pazopanib, and demonstrated the effectiveness of this drug in routine clinical practice. However, in this series of 278 patients, we could not obtain enough information on the effectiveness of pazopanib in special subpopulations such as non-clear cell histologies, and others subgroups, due to a small simple size of each of these subpopulations. On the other hand, after the results of RECORD-1 and AXIS trials, switching to everolimus or axitinib is the current approach for patients who progresses to a first-line TKI. However, these pivotal studies did not include patients treated with first-line pazopanib study because this drug was not available at that time. The results of the SPAZO study also suggested that the effectiveness of second-line targeted therapies (TT) after pazopanib in routine clinical practice is similar to the observed in clinical trials after sunitinib, sorafenib or bevacizumab. In addition, the preliminary results indicated that there are not meaningful differences in the effectiveness of TKI or mTOR inhibitors after pazopanib, when the results are adjusted by the IMDC prognostic classification. However, the IMDC prognostic classification for second-line TT has not yet been validated for patients who receive pazopanib as first-line. In addition our sample size was not large enough to make a comparison of effectiveness between mTOR inhibitors and antiVEGF for each prognostic subgroups of the IMDC.

Based on that, the Spanish Oncologic Genitourinary Group has decided to launch the SPAZO-2 study, in which we intend to prolong the follow up of patients included in SPAZO, and to increase the sample size with new patients from new centres, in order to obtain a larger sample in each of the subpopulations of interest, with the objective of obtaining more information about the above questions.