Activity of second line axitinib in metastatic renal cell carcinoma (mRCC) patients treated with sunitinib: Results from SAX Italian real world trial.

Abstract

e16054 Background: Axitinib, a selective tyrosine kinase inhibitor (TKI), is currently approved for the treatment of mRCC after failure of prior treatment with sunitinib or cytokine, according to AXIS trial results. The best sequence hasn’t been established: both axitinib and everolimus (a mTOR inhibitor) are viable therapeutic options, although recently immunotherapy agents entered this setting. This Italian multi-institutional retrospective analysis evaluated outcomes of Axitinib in exclusive sequence after sunitinib in second line treatment of mRCC Methods: Medical records of 148 patients treated with Axitinib from 21 Italian Oncology Centers were retrospectively assessed: PFS, OS, ORR DCR, and safety profile of axitinib were primary endpoints. Results: Median PFS and OS were 7.14 and 15.5 months, respectively. Overall, axitinib at standard schedule of 5 mg bid, was well tolerated, with no grade 4 toxicity event. Most common adverse events were hypertension (26% of the cases), fatigue (50 %), hypothyroidism (18%). At univariate analysis, when patients were stratified by Heng score, mPFS was 5.8, 7.0 and 9.0 months according to poor, intermediate and favourable risk group, respectively. When stratified by median duration of prior sunitinib therapy (≥ 13,1 mo vs < 13,1 mo), there was a statistically significant difference in PFS with 8.8 vs 6.3 months, respectively. Disease control rate (DCR) to previous sunitinib treatment was associated to longer PFS with axitinib ( 8.0 months vs4.0 months). The sequence sunitinib-axitinib was well tolerated, with a mOS of 41 months. At multivariate analysis, prognostic factors for progression were gender (p-value = 0,006), DCR to axitinib (p < 0,0001) and to previous sunitinib (p = 0,041); DCR to axitinib (p = < 0,0001), nephrectomy (p = 0,002) and Heng score (p = 0,025) independently affected overall survival. Conclusions: The preliminary SAX results in the real world population are consistent with available literature. The study confirms that Axitinib is effective and safe in routine clinical practice, and its efficacy seems to be greater in patients who most benefited from first-line sunitinib.