Phase 2 Multicenter Single-Arm Study of Second-Line Axitinib in Favorable Risk Patients with Metastatic Renal Cell Carcinoma: FavorAx
Targeted therapy with axitinib resulted in a greater objective response rate and prolonged progression-free survival (PFS) compared to sorafenib in patients with previously treated metastatic renal cell carcinoma (mRCC) in the phase 3 AXIS study, where 75% of patients had intermediate and poor International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) risk.
In this phase 2 study (FavorAx), we assessed the activity of axitinib in mRCC patients with a favorable risk and history of prior vascular endothelial growth factor receptor (VEGFR)-directed therapy.
Patients and Methods
Patients were required to have clear-cell mRCC, favorable risk according to IMDC criteria, and to have received first-line treatment with sunitinib or pazopanib. Prior treatment with other agents was not permitted. The primary endpoint of the study was 5 months PFS. Additional endpoints included response rate, safety, PFS, and overall survival (OS).
A total of 21 patients were enrolled, 62% of whom were male. The mean age was 60 years. Eleven (52%) patients had two or more metastatic sites. 67% and 33% of patients received first-line sunitinib or pazopanib, respectively, with a median PFS of 17 months [95% confidence interval (CI), 14–20]. After a median follow-up of 25 months, the median PFS was 19 months (95% CI, 15–23). The current study did achieve its primary endpoint based on the 5-month PFS of 100%. The median OS was not yet reached. The 18 months OS rate was 85.7%. The objective response rate was 33% and one patient achieved a complete response. Seven patients had dose escalation of axitinib and four patients had dose reduction. Grade 3 adverse events were observed in 19% of cases. There was no discontinuation of therapy due to toxicity.
The encouraging PFS and favorable safety profile observed in the FavorAx study support the administration of axitinib in mRCC patients with favorable IMDC risk and a history of prior sunitinib or pazopanib.
Compliance with Ethical Standards
This study was funded by a grant from the Kidney Cancer Research Bureau. No external funding was used in the preparation of this manuscript.
Conflict of Interest
Ilya Tsimafeyeu, Pavel Borisov, Ahmed Abdelgafur, Roman Leonenkov, Olga Novikova, Irina Guseva, Marina Demchenkova, Nadezhda Mikhailova, Andrey Semenov, Zakhar Yurmazov, Irina Sivunova, Madina Ramazanova, Sergey Gamayunov, Dmitry Kosov, and Gennady Bratslavsky declare that they have no conflicts of interest that might be relevant to the contents of this manuscript.
- 2.Kaprin AD, Starinskiy VV, Petrova GV. Malignant tumors in Russia in 2016 (morbidity and mortality). Moscow, 2018, 250 pp. ISBN 978-5-85502-234-6.Google Scholar
- 11.National Comprehensive Cancer Network Clinical Practice Guidelines in Oncology: Kidney Cancer, version 3.2018.Google Scholar