The progression-free survival (PFS) benefit with cabozantinib in the CABOSUN trial was confirmed, but overall survival (OS) was not significantly different from sunitinib among patients with untreated advanced renal cell carcinoma (RCC), according to updated data presented at the European Society of Medical Oncology (ESMO) 2017 Congress in Spain.1

Investigator-assessed results of the CABOSUN trial were previously published in 2016 and demonstrated a significant improvement in PFS with cabozantinib compared with sunitinib among patients with untreated RCC (hazard ratio [HR], 0.66; 95% CI, 0.46-0.95; P = .12). This analysis included the independent radiology committee (IRC) review and updated OS data after a data cut-off of July 1, 2017.

In the open-label, phase 2 CABOSUN trial, 157 patients with untreated, locally advanced or metastatic clear cell RCC were randomly assigned to receive cabozantinib or sunitinib.

The updated IRC data demonstrated an objective response rate of 20% (95% CI, 12-31%) with cabozantinib compared with 9% (95% CI, 4-18%) with sunitinib. The disease control rate was 75% and 47% with cabozantinib and sunitinib, respectively.

PFS was significantly prolonged with cabozantinib, with a median of 8.6 months compared with 5.3 months with sunitinib (HR, 0.48; 95% CI, 0.31-0.74; P = .0008), by IRC review.

OS, however, was similar between groups, though the cabozantinib arm trended toward an improved median OS at 26.6 months compared with 21.2 months with sunitinib (HR, 0.80; 95% CI, 0.52-1.21; P = .29).

Discontinuation due to adverse events (AEs) occurred among 21% and 22% of patients in the cabozantinib and sunitinib arms, respectively. The most common all-cause grade 3/4 AEs included diarrhea, hypertension, and fatigue.

These data confirm the initial findings by investigator review, and suggest that cabozantinib is effective for the first-line treatment of advanced, clear cell RCC.

Reference

  1. Exelixis and Ipsen announce results from phase 2 CABOSUN trial of cabozantinib versus sunitinib in previously untreated advanced renal cell carcinoma at ESMO. BusinessWire website. http://www.businesswire.com/news/home/20170909005044/en/Exelixis-Ipsen-Announce-Results-Phase-2-CABOSUN. Published September 9, 2017. Accessed September 13, 2017.