Exelixis (EXEL) on Monday reported detailed results of a phase 3 trial of zanzalintinib in combination with atezolizumab versus regorafenib in patients with previously treated non-microsatellite instability-high metastatic colorectal cancer.

The median overall survival in the intention-to-treat population was 10.9 months with the combination versus 9.4 months with regorafenib at a median follow-up of 18 months.

The company said it observed a trend for improvement in progression-free survival with the combination in the intention-to-treat population, "though statistical superiority cannot be claimed at this time due to the pre-specified hierarchical testing strategy."

Deaths considered pertaining to treatment by investigators were two for zanzalintinib, two for atezolizumab, one for the combination and one for regorafenib, the company said.

Exelixis shares were down 11% in recent premarket activity.