Axitinib versus sorafenib as first‑line therapy in patients with metastatic renal cell carcinoma (mRCC).

Abstract

LBA348 Background: In the phase III AXIS trial, second-line therapy with axitinib resulted in significantly longer progression-free survival (PFS) versus sorafenib for mRCC. We conducted a multicenter, randomized, open-label, phase III trial to compare PFS of axitinib vs sorafenib as first-line therapy. Methods: Patients with untreated, measurable (RECIST v1.0), clear‑cell mRCC and Eastern Cooperative Oncology Group performance status (PS) 0 or 1 were randomized 2:1 to axitinib 5 mg twice daily (BID) or sorafenib 400 mg BID. Randomization was stratified by PS. Primary endpoint was PFS per independent radiology committee. The study had 90% power to detect a 78% PFS improvement from 5.5 mo with sorafenib to 9.8 mo with axitinib, corresponding to a hazard ratio (HR) of 0.561 (overall 1-sided α=0.025). Results: Patients (N=288) were mainly from Eastern Europe (51%), Asia (25%), North America (14%), or South America (10%).Patient baseline characteristics for axitinib (n=192) vs sorafenib (n=96) included: median age, 58y vs 58y; male, 70% vs 77%; white, 71% vs 69%; favorable risk, 49% vs 55%; PS 0, 57% vs 57%; nephrectomy, 85% vs 90%. Median (m) PFS was 10.1 vs 6.5 mo with axitinib vs sorafenib (HR adjusted for PS, 0.767; 95% confidence interval [CI], 0.559–1.053; 1‑sided P=0.0377). In patients with PS 0 and 1, respectively, mPFS with axitinib vs sorafenib was 13.7 vs 6.6 mo (HR, 0.644; 95% CI, 0.419–0.991; 1‑sided P=0.022) and 6.5 vs 6.4 mo (HR, 0.931; 95% CI, 0.585–1.482; 1‑sided P=0.38). Objective response rates (ORRs) with axitinib vs sorafenib were 32.3% vs 14.6% (1‑sided P=0.0006 adjusted for PS). Overall survival data were not mature. All-grade all‑causality adverse events (≥20%) with axitinib vs sorafenib were diarrhea (50% vs 40%), hypertension (49% vs 29%), weight decreased (37% vs 24%), fatigue (33% vs 26%), decreased appetite (29% vs 19%), palmar-plantar erythrodysesthesia (26% vs 39%), dysphonia (23% vs 10%), asthenia (21% vs 16%), and hypothyroidism (21% vs 7%). Conclusions: The study did not achieve its primary endpoint statistically, but axitinib demonstrated numerically longer mPFS and significantly higher ORR vs sorafenib, with an acceptable safety profile, as first-line therapy for mRCC. Clinical trial information: NCT00920816.