Overall and progression-free survival with everolimus, temsirolimus, or sorafenib as second targeted therapies for metastatic renal cell carcinoma: A retrospective U.S. chart review.

4612 Background: Tyrosine kinase inhibitors (TKIs) (sorafenib, sunitinib, pazopanib) and inhibitors of the mammalian target of rapamycin (mTORs) (everolimus, temsirolimus) are used for treating metastatic renal cell carcinoma (mRCC) following initial treatment with a TKI. This study’s objective was to establish the effectiveness of the most commonly used 2nd line treatments based on real-use data. Methods: mRCC patients who received a TKI as their 1st targeted therapy and everolimus, temsirolimus or sorafenib as their 2nd therapy were identified by oncologists (85% in community practice) throughout the US as part of an online chart review study. Baseline characteristics were assessed prior to 2nd targeted therapy, including type and duration of initial TKI, response, histological subtype, performance status, and sites of metastasis. Overall survival (OS) and progression free-survival (PFS) were assessed after initiating 2nd targeted therapy. OS and PFS were compared between treatment groups using Cox proportional hazards models adjusted for baseline characteristics. Results: Charts were reviewed for 233, 178, and 123 mRCC patients receiving everolimus, temsirolimus, and sorafenib after an initial TKI, respectively. Median age was 64 years and 70.4% were male. Prior to initiating a 2nd targeted therapy, 86.0% used sunitinib and 85.9% had disease progression. After adjusting for baseline characteristics, everolimus was associated with significantly prolonged OS compared to temsirolimus (hazard ratio [HR] 0.56; CI 0.40-0.78; p<0.001) and sorafenib (HR 0.65; CI 0.42-0.99; p=0.047). Everolimus was associated with significantly longer PFS compared to temsirolimus (HR 0.73; CI 0.55-0.96; p=0.025), and non-statistically significant longer PFS compared to sorafenib (HR 0.75; CI 0.53-1.07; p=0.110). Results were similar in the subgroup with sunitinib as 1st targeted therapy and the subgroup with progression on 1st TKI. Conclusions: Among mRCC patients with prior TKI treatment, everolimus was associated with significantly prolonged OS and PFS compared to temsirolimus and significantly prolonged OS compared to sorafenib.