Exelixis and Ipsen Announce Cabozantinib in Combination with an Immune Checkpoint Inhibitor Significantly Improved Progression-Free Survival in Phase 3 COSMIC-312 Pivotal Trial in Patients with Previously Untreated Advanced Liver Cancer

ALAMEDA, Calif. & PARIS – June 28, 2021 – Exelixis, Inc. (NASDAQ: EXEL) and Ipsen (Euronext: IPN; ADR: IPSEY) today announced that COSMIC-312, the ongoing phase 3 pivotal trial evaluating cabozantinib (CABOMETYX®) in combination with atezolizumab versus sorafenib in patients with previously untreated advanced hepatocellular carcinoma (HCC) met one of the primary endpoints, demonstrating significant improvement in progression-free survival (PFS) at the planned primary analysis. A prespecified interim analysis for the second primary endpoint of overall survival (OS), conducted at the same time as the primary analysis for PFS, showed a trend favoring the combination of cabozantinib and atezolizumab, but did not reach statistical significance. Based on the preliminary OS data, Exelixis anticipates that the probability of reaching statistical significance at the time of the final analysis is low. The trial will continue as planned to the final analysis of OS; results are anticipated in early 2022.

In the analysis of the primary endpoint of PFS in the PFS intent-to-treat population, cabozantinib in combination with atezolizumab significantly reduced the risk of disease progression or death by 37% compared with sorafenib (hazard ratio [HR]: 0.63; 99% confidence interval [CI]: 0.44-0.91; P=0.0012). Safety for the combination appeared to be consistent with the known safety profiles of the individual medicines, and no new safety signals were identified. Exelixis plans to discuss the trial results and next steps for a potential regulatory filing with the U.S. Food and Drug Administration (FDA).

“While we are encouraged by the data supporting the potential for the combination of cabozantinib and atezolizumab to reduce the risk of disease progression or death, we are disappointed by the interim result of lack of significant improvement on overall survival versus the comparator arm,” said Michael M. Morrissey, Ph.D., Exelixis’ President and Chief Executive Officer. “As these data continue to mature, we are working to understand the potential impact of various contributing factors on the results, including patient demographics, subsequent anti-cancer therapy and the impact of COVID-19 on the trial. We anticipate presenting the results at a future medical conference.”

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