Vosevi Provides a New Option for People with HCV Who Have Not Achieved Cure with Prior Direct-Acting Antiviral Treatment ?

FOSTER CITY, Calif.--(BUSINESS WIRE)--Dec. 20, 2019-- Gilead Sciences, Inc. (NASDAQ: GILD) announced today that the China National Medical Products Administration (NMPA) has approved Vosevi^? (sofosbuvir 400mg/velpatasvir 100mg/voxilaprevir 100mg), a once-daily single-tablet regimen for the treatment of chronic hepatitis C virus (HCV) infection in adults without cirrhosis or with compensated cirrhosis who have failed prior treatment with a direct-acting antiviral (DAA) therapy. The approval of Vosevi in China is supported by two global Phase 3 studies, POLARIS-1 and POLARIS-4, which evaluated 12 weeks of treatment with Vosevi among adults with HCV genotype 1-6 with or without compensated cirrhosis who had failed prior DAA treatment with or without an NS5A inhibitor. Across POLARIS-1 and POLARIS-4, 97 percent of patients treated with Vosevi (n=431/445) achieved SVR12, the primary endpoint to determine cure rate, defined as HCV RNA undetectable 12 weeks after completing therapy. ?People who have not achieved HCV cure with direct acting antiviral medicines are often faced with limited choices for re-treatment,? said Professor Lai Wei, Director of Hepatology and Pancreatic Center, Tsinghua University-affiliated Beijing Tsinghua Changgung Hospital. ?With high cure rates across all genotypes, Vosevi is a promising option for people who require a new regimen to potentially achieve an HCV cure.? The most common adverse reactions (=10 percent) experienced by patients treated with Vosevi in POLARIS-1 and POLARIS-4 were headache, fatigue, diarrhea and nausea. The proportion of patients who permanently discontinued treatment with Vosevi due to adverse events was 0.2 percent. In China, approximately 10 million people are infected with HCV and it is the fourth most commonly reported infectious disease. HCV genotypes 1, 2, 3 and 6 account for more than 96 percent of all cases. ?The approval of Vosevi in China means that many more patients with difficult-to-treat chronic HCV infection now have another chance at cure,? said Merdad Parsey, MD, PhD, Chief Medical Officer, Gilead Sciences. ?It also represents another important step forward in achieving the public health goal of eliminating HCV in China and worldwide.? Vosevi received marketing approval from the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA) in 2017. In the United States, Vosevi has a Boxed Warning in its product label regarding the risk of hepatitis B virus (HBV) reactivation in HCV/HBV coinfected patients. See below for U.S. Important Safety Information and Indication. U.S. Important Safety Information and Indications for Vosevi BOXED WARNING: RISK OF HEPATITIS B VIRUS REACTIVATION IN HCV/HBV COINFECTED PATIENTS Test all patients for evidence of current or prior hepatitis B virus (HBV) infection before initiating treatment with Vosevi. HBV reactivation has been reported in HCV/HBV coinfected patients who were undergoing or had completed treatment with HCV direct-acting antivirals (DAAs) and were not receiving HBV antiviral therapy. Some cases have resulted in fulminant hepatitis, hepatic failure, and death. Cases have been reported in patients who are HBsAg positive, in patients with serologic evidence of resolved HBV and also in patients receiving certain immunosuppressant or chemotherapeutic agents; the risk of HBV reactivation associated with treatment with HCV DAAs may be increased in patients taking these other agents. Monitor HCV/HBV coinfected patients for hepatitis flare or HBV reactivation during HCV treatment and post-treatment follow-up. Initiate appropriate patient management for HBV infection as clinically indicated. Contraindications Vosevi is contraindicated with rifampin. Warnings and Precautions Risk of Hepatic Decompensation/Failure in Patients with Evidence of Advanced Liver Disease: Post-marketing cases of hepatic decompensation/failure, some fatal, have been reported in patients treated with HCV NS3/4A protease inhibitor-containing regimens, including Vosevi. Reported cases occurred in patients with baseline cirrhosis with and without moderate or severe liver impairment (Child-Pugh B or C). In patients with compensated cirrhosis (Child-Pugh A) or evidence of advanced liver disease such as portal hypertension, perform hepatic laboratory testing as clinically indicated; and monitor for signs and symptoms of hepatic decompensation such as the presence of jaundice, ascites, hepatic encephalopathy, and variceal hemorrhage. Discontinue Vosevi in patients who develop evidence of hepatic decompensation/failure. Vosevi is not recommended in patients with moderate to severe hepatic impairment or those with any history of prior hepatic decompensation/failure. Serious Symptomatic Bradycardia When Coadministered with Amiodarone: Amiodarone is not recommended for use with Vosevi due to the risk of symptomatic bradycardia, particularly in patients also taking beta blockers or with underlying cardiac comorbidities and/or with advanced liver disease. A fatal cardiac arrest was reported in a patient taking amiodarone who was coadministered a sofosbuvir-containing regimen. In patients without alternative, viable treatment options, cardiac monitoring is recommended. Patients should seek immediate medical evaluation if they develop signs or symptoms of bradycardia. Risk of Reduced Therapeutic Effect Due to Concomitant Use of Vosevi with P-gp Inducers and/or Moderate to Potent Inducers of CYP2B6, CYP2C8 or CYP3A4: St. John?s wort and carbamazepine are not recommended for use with Vosevi as they may significantly decrease sofosbuvir, velpatasvir and/or voxilaprevir plasma concentrations. Adverse Reactions The most common adverse reactions (=10%, all grades) observed with treatment with VOSEVI for 12 weeks were headache, fatigue, diarrhea and nausea. Drug Interactions Coadministration of Vosevi is not recommended with phenytoin, phenobarbital, oxcarbazepine, rifabutin, rifapentine, atazanavir, lopinavir, tipranavir/ritonavir, efavirenz, rosuvastatin, pitavastatin and cyclosporine due to changes (decreased or increased) in concentrations of sofosbuvir, velpatasvir, voxilaprevir and/or the other agent. Consult the full Prescribing Information for Vosevi for more information on potentially significant drug interactions, including clinical comments. U.S. INDICATION Vosevi is indicated for the treatment of chronic hepatitis C virus (HCV) infection in adults without cirrhosis or with compensated cirrhosis who have failed prior treatment with an HCV direct-acting antiviral (DAA) who have:

• genotype 1, 2, 3, 4, 5, or 6 infection and have previously been treated with an HCV regimen containing an NS5A inhibitor
• genotype 1a or 3 infection and have previously been treated with an HCV regimen containing sofosbuvir without an NS5A inhibitor

About Gilead Sciences Gilead Sciences, Inc. is a research-based biopharmaceutical company that discovers, develops and commercializes innovative medicines in areas of unmet medical need. The company strives to transform and simplify care for people with life-threatening illnesses around the world. Gilead has operations in more than 35 countries worldwide, with headquarters in Foster City, California. Forward-Looking Statement This press release includes forward-looking statements, within the meaning of the Private Securities Litigation Reform Act of 1995, that are subject to risks, uncertainties and other factors, including the risk that physicians may not see the benefits of prescribing Vosevi for the treatment of adults with chronic HCV infection. These risks, uncertainties and other factors could cause actual results to differ materially from those referred to in the forward-looking statements. The reader is cautioned not to rely on these forward-looking statements. These and other risks are described in detail in Gilead?s Quarterly Report on Form 10-Q for the quarter ended September 30, 2019, as filed with the U.S. Securities and Exchange Commission. All forward-looking statements are based on information currently available to Gilead, and Gilead assumes no obligation to update any such forward-looking statements.

U.S. full Prescribing Information for Vosevi, including BOXED WARNING, is available at www.gilead.com.

Vosevi is a registered trademark of Gilead Sciences, Inc., or its related companies.

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