A combination with Exelixis' experimental drug zanzalintinib has beaten Bayer's gastrointestinal cancer drug Stivarga in a Phase 3 trial . The overall survival success brings Exelixis one step closer to its goal of developing the oral tyrosine kinase inhibitor into a product with annual sales of 5 billion dollars.
Exelixis is developing zanzalintinib as a successor to its lead oncology drug Cabometyx. By improving properties such as pharmacokinetic half-life, the company has developed a molecule that it believes could be approved for a range of diseases and significantly outperform Cabometyx's peak sales. The Phase 3 colorectal cancer trial was an important early test for zanzalintinib.
Researchers randomized 901 patients to receive Stivarga or zanzalintinib in combination with Roche's checkpoint inhibitor Tecentriq. Overall survival in previously treated metastatic colorectal cancer without microsatellite instability was significantly longer with the combination therapy than with Stivarga.
Analysts at William Blair said in a note to investors that meeting the study's co-primary endpoint represented a "significant commercial opportunity for the emerging product". The patient population covered by the endpoint represents the largest commercial opportunity for zanzalintinib, analysts said, estimating peak risk-adjusted sales in the US at $875 million.
