– Exelixis to submit a supplemental New Drug Application to the U.S. Food and Drug Administration (FDA) in the first quarter of 2018; cabozantinib previously granted orphan drug designation by FDA –

– Data to be submitted for presentation at an upcoming medical meeting –

SOUTH SAN FRANCISCO, CA, USA I October 16, 2017 I Exelixis, Inc. (NASDAQ:EXEL) today announced that its global phase 3 CELESTIAL trial met its primary endpoint of overall survival (OS), with cabozantinib providing a statistically significant and clinically meaningful improvement in median OS compared to placebo in patients with advanced hepatocellular carcinoma (HCC). The independent data monitoring committee for the study recommended that the trial should be stopped for efficacy following review of the second planned interim analysis. CELESTIAL is a randomized, global phase 3 trial of cabozantinib versus placebo in patients with advanced HCC who have been previously treated with sorafenib. The safety data in the study were consistent with the established profile of cabozantinib. Based on these results, Exelixis plans to submit a supplemental New Drug Application (sNDA) to the U.S. Food and Drug Administration (FDA) in the first quarter of 2018. Detailed results from CELESTIAL will be submitted for presentation at a future medical conference.

“We are excited that these positive results from the phase 3 CELESTIAL trial bring us one step closer to the potential of offering previously treated patients with this aggressive form of advanced liver cancer a much-needed new treatment option,” said Gisela Schwab, M.D., President, Product Development and Medical Affairs and Chief Medical Officer, Exelixis. “This is an important milestone for the cabozantinib development program; we are committed to studying cabozantinib in a range of tumor types as part of our mission to deliver medicines that improve treatment outcomes and give patients hope for the future.”

Exelixis will discuss the trial results with regulatory authorities and determine next steps for the trial, including offering patients currently receiving placebo the opportunity to cross over to cabozantinib.

In March 2017, the FDA granted orphan drug designation to cabozantinib for the treatment of advanced HCC. Orphan drug designation is granted to treatments for diseases that affect fewer than 200,000 people in the U.S. and provides certain incentives for medications intended for the treatment, diagnosis or prevention of rare diseases. At present, these incentives include seven years of marketing exclusivity for the orphan indication, certain federal grants, tax credits, and waiver of certain FDA fees.

About the CELESTIAL Study
CELESTIAL is a randomized, double-blind, placebo-controlled study of cabozantinib in patients with advanced HCC conducted at more than 100 sites globally in 19 countries. The trial was designed to enroll 760 patients with advanced HCC who received prior sorafenib and may have received up to two prior systemic cancer therapies for HCC and had adequate liver function. Enrollment of the trial was completed in September 2017. Patients were randomized 2:1 to receive 60 mg of cabozantinib once daily or placebo and were stratified based on etiology of the disease (hepatitis C, hepatitis B or other), geographic region (Asia versus other regions) and presence of extrahepatic spread and/or macrovascular invasion (yes or no). No cross-over was allowed between the study arms.

The primary endpoint for the trial is OS, and secondary endpoints include objective response rate and progression-free survival. Exploratory endpoints include patient-reported outcomes, biomarkers and safety.

Based on available clinical trial data from various published trials conducted in the second-line setting of advanced HCC, the CELESTIAL trial statistics for the primary endpoint of OS assumed a median OS of 8.2 months for the placebo arm. A total of 621 events provide the study with 90 percent power to detect a 32 percent increase in median OS (HR = 0.76) at the final analysis. Two interim analyses were planned and conducted at 50 percent and 75 percent of the planned 621 events.

About HCC
Liver cancer is the third-leading cause of death worldwide, and hepatocellular carcinoma (HCC) is the most common form, making up about three-fourths of the nearly 41,000 cases that will be diagnosed in 2017 in the U.S.1,2 Without treatment, patients with advanced disease usually survive less than 6 months, and it is estimated that 29,000 people will die due to liver cancer in the U.S.2,3 Worldwide, nearly 800,000 new cases are diagnosed annually, and the disease accounts for more than 700,000 deaths each year.4

About CABOMETYX® (cabozantinib)
CABOMETYX is the tablet formulation of cabozantinib. Its targets include MET, AXL and VEGFR-1, -2 and -3. In preclinical models, cabozantinib has been shown to inhibit the activity of these receptors, which are involved in normal cellular function and pathologic processes such as tumor angiogenesis, invasiveness, metastasis and drug resistance. CABOMETYX is available in 20 mg, 40 mg or 60 mg doses. The recommended dose is 60 mg orally, once daily.

On April 25, 2016, the FDA approved CABOMETYX tablets for the treatment of patients with advanced RCC who have received prior anti-angiogenic therapy. In February of 2016, Exelixis and Ipsen jointly announced an exclusive licensing agreement for the commercialization and further development of cabozantinib indications outside of the United States, Canada and Japan. This agreement was amended in December of 2016 to include commercialization rights for Ipsen in Canada. On September 9, 2016, the European Commission approved CABOMETYX tablets for the treatment of advanced RCC in adults who have received prior vascular endothelial growth factor (VEGF)-targeted therapy in the European Union, Norway and Iceland.

On January 30, 2017, Exelixis and Takeda Pharmaceutical Company Limited announced an exclusive licensing agreement for the commercialization and further clinical development of cabozantinib for all future indications in Japan, including RCC.

CABOMETYX is not indicated for the treatment of advanced HCC.

SOURCE: Exelixis