A phase II clinical study evaluating the efficacy and safety of neoadjuvant and adjuvant sunitinib in previously untreated patients with metastatic renal cell carcinoma (mRCC)(NeoSun).

Abstract

e16087 Background: Sunitinib improves clinical outcomes in patients (pts) with mRCC. The single arm phase II NeoSun trial was designed to investigate its added value to nephrectomy, and to explore translational biological and imaging biomarkers. Methods: Pts with mRCC, scheduled for nephrectomy, no prior systemic therapy were recruited to receive 50mg OD sunitinib for 12 days, then post-surgery on a 4 week-on, 2 week-off, repeating 6 week cycle until disease progression. Diffusion-weighted, BOLD and dynamic contrast enhanced MR imaging (DW-MRI, DCE-MRI) and research blood sample collection were performed at baseline and end of 12 days. CT Imaging was performed at baseline, pre- and post-surgery, and then every 2 cycles. The primary endpoint was objective response rate (RECIST). Secondary endpoints included changes in diffusion DW-MRI, DCE- MRI of the tumour following 12 days suntinib, overall survival (OS), progression-free survival (PFS), response duration, surgical morbidity/mortality, and toxicity. Results: 14 pts received pre-surgery sunitinib, 71% (10/14) took the planned 12 doses. All 14 underwent total nephrectomy, and 13 recommenced sunitinib post-operatively. The mean number of post-surgery cycles was 11 (range 2 – 22). 58.3% (7/12) of pts achieved confirmed response (95% CI: 27.7 - 84.8%).91.7% (11/12) achieved objective clinical benefit (95% CI: 61.5 - 99.8%). Median OS is 33.7m and median PFS is 15.7m. Amongst those achieving PR/CR, median response duration is 8.7m. No unexpected surgical or sunitinib-related toxicities or complications were observed and the mean number of days from surgery to hospital discharge was 5.9 (range 3.0 – 17.0).There was a trend forOS to be better in pts with high baseline plasma VEGF-A (p = 0.06) or VEGF-C (p = 0.02) expression. A larger % tumour volume reduction after 12 days treatment is correlated with a smaller baseline % necrosis (coefficient = -0.51, p = 0.03). Conclusions: Sunitinib is effective and safe when given before and after nephrectomy to previously untreated pts with mRCC. Neoadjuvant studies such as NeoSun can safely explore translational biological and imaging endpoints. Clinical trial information: 2005-004502-82.