FOSTER CITY, Calif.--(BUSINESS WIRE)--Gilead Sciences, Inc. (Nasdaq: GILD) today announced new, long-term data from open-label extensions (OLE) of two Phase 3 studies (Study 1489 and Study 1490) of Biktarvy^??(bictegravir 50 mg/emtricitabine 200 mg/tenofovir alafenamide 25 mg tablets, B/F/TAF), demonstrating the sustained efficacy and safety profile and no treatment-emergent resistance with Biktarvy for the treatment of HIV-1 in treatment-na?ve adults. The data were presented at the 28th Conference on Retroviruses and Opportunistic Infections (virtual?CROI 2021). In both studies, >98% of participants who initiated treatment with Biktarvy and remained in the study achieved and maintained an undetectable viral load (HIV-1 RNA <50 copies/mL) through four years of follow-up (n=235/237 for study 1489, n=241/243 for study 1490). The high efficacy and durable viral suppression were also observed in participants who switched to Biktarvy from a dolutegravir-containing triple therapy for the 48-week OLE periods (n=212 for study 1489, n=225 for study 1490). No treatment-emergent resistance to any components of Biktarvy occurred in participants treated with Biktarvy. ?Gilead is committed to developing innovative HIV treatments, like Biktarvy, that help to address the unmet needs of people living with HIV today, including achieving and maintaining an undetectable viral load over the long-term,? said Diana Brainard, MD, Senior Vice President, Virology Therapeutic Area, Gilead Sciences. ?These data reinforce that Biktarvy provides durable viral suppression, strong efficacy and a high barrier to resistance in both adults that are new to HIV therapy and those replacing their existing treatment.? Gilead presented additional Biktarvy data at?virtual?CROI 2021, including findings from a 144-week analysis of the same Phase 3 studies (Study 1489 and Study 1490), which demonstrated that people living with HIV who received initial therapy with Biktarvy reached and maintained an undetectable viral load with no treatment-emergent resistance through 144 weeks (n=634). In a subgroup analysis of participants with transmitted-drug resistance (TDR, n=248) based on retrospective sequencing of baseline samples, Biktarvy achieved comparably high levels of durable viral suppression through 144 weeks among participants with and without TDR (98% vs. 97%; as treated analysis). ?As a clinician, my goal is to initiate treatment immediately after diagnosis with a therapy that achieves and maintains virologic control over the long-term,? said Kimberly Workowski, MD, Professor of Medicine, Emory University. ?The data presented at CROI highlight that Biktarvy can achieve long-term viral suppression at four years among a range of people living with HIV and supports further study for patients with certain transmitted drug-resistant HIV.? The use of Biktarvy in individuals with known resistance to the components of Biktarvy is investigational; this use is not approved by the U.S. FDA, and the safety and efficacy of Biktarvy for this use has not been established. Please see below for the U.S. Indication and Important Safety Information for Biktarvy. Biktarvy does not cure HIV or AIDS. About Studies 1489 and 1490 Study 1489 and Study 1490 are Phase 3, randomized, double-blind, active-controlled studies. For 144 weeks, treatment-na?ve participants were blinded to receive either Biktarvy (n=634) or a dolutegravir-containing triple therapy (n=640). Treatment outcomes were assessed at week 144 and showed participants in both groups achieved an undetectable viral load, with no treatment-emergent resistance. Beyond week 144, participants were able to receive Biktarvy in an active OLE phase for up to 96 weeks. Study 1489 and Study 1490 are ongoing. U.S. Important Safety Information for Biktarvy BOXED WARNING: POST TREATMENT ACUTE EXACERBATION OF HEPATITIS B

• Severe acute exacerbations of hepatitis B have been reported in patients who are coinfected with HIV-1 and HBV and have discontinued products containing emtricitabine (FTC) and/or tenofovir disoproxil fumarate (TDF) and may occur with discontinuation of BIKTARVY.?Closely monitor hepatic function with both clinical and laboratory follow-up for at least several months in patients who are coinfected with HIV-1 and HBV and discontinue BIKTARVY. If appropriate, anti-hepatitis B therapy may be warranted.

Contraindications

• Coadministration:?Do not use BIKTARVY with dofetilide or rifampin.

Warnings and precautions

• Drug interactions:?See Contraindications and Drug Interactions sections. Consider the potential for drug interactions prior to and during BIKTARVY therapy and monitor for adverse reactions.
• Immune reconstitution syndrome,?including the occurrence of autoimmune disorders with variable time to onset, has been reported.
• New onset or worsening renal impairment:?Postmarketing cases of renal impairment, including acute renal failure, proximal renal tubulopathy (PRT), and Fanconi syndrome have been reported with TAF-containing products; while most of these cases were characterized by potential confounders that may have contributed to the reported renal events, it is also possible these factors may have predisposed patients to tenofovir-related adverse events. Do not initiate BIKTARVY in patients with estimated creatinine clearance (CrCl) <30 mL/min except in virologically-suppressed adults <15mL/min who are receiving chronic hemodialysis. Patients with impaired renal function and/or taking nephrotoxic agents (including NSAIDs) are at increased risk of renal-related adverse reactions. Discontinue BIKTARVY in patients who develop clinically significant decreases in renal function or evidence of Fanconi syndrome. Renal monitoring:?Prior to or when initiating BIKTARVY and during therapy, assess serum creatinine, CrCl, urine glucose, and urine protein in all patients as clinically appropriate. In patients with chronic kidney disease, assess serum phosphorus.
• Lactic acidosis and severe hepatomegaly with steatosis:?Fatal cases have been reported with the use of nucleoside analogs, including FTC and TDF. Discontinue BIKTARVY if clinical or laboratory findings suggestive of lactic acidosis or pronounced hepatotoxicity develop, including hepatomegaly and steatosis in the absence of marked transaminase elevations.

Adverse reactions

• Most common adverse reactions?(incidence =5%; all grades) in clinical studies through Week 144 were diarrhea (6%), nausea (6%), and headache (5%).

Drug interactions

• Prescribing information:?Consult the full prescribing information for BIKTARVY for more information on Contraindications, Warnings, and potentially significant drug interactions, including clinical comments.
• Enzymes/transporters:?Drugs that induce P-gp or induce both CYP3A and UGT1A1 can substantially decrease the concentration of components of BIKTARVY. Drugs that inhibit P-gp, BCRP, or inhibit both CYP3A and UGT1A1 may significantly increase the concentrations of components of BIKTARVY. BIKTARVY can increase the concentration of drugs that are substrates of OCT2 or MATE1.
• Drugs affecting renal function:?Coadministration of BIKTARVY with drugs that reduce renal function or compete for active tubular secretion may increase concentrations of FTC and tenofovir and the risk of adverse reactions.

Dosage and administration

• Dosage:?Patients weighing =25 kg: 1 tablet taken once daily with or without food.
• Renal impairment:?Not recommended in patients with CrCl <30 mL/min.
• Hepatic impairment:?Not recommended in patients with severe hepatic impairment.
• Prior to or when initiating:?Test patients for HBV infection.
• Prior to or when initiating, and during treatment:?As clinically appropriate, assess serum creatinine, CrCl, urine glucose, and urine protein in all patients. In patients with chronic kidney disease, assess serum phosphorus.

Pregnancy and lactation

• Pregnancy:?There is insufficient human data on the use of BIKTARVY during pregnancy. Dolutegravir, another integrase inhibitor, has been associated with neural tube defects. Discuss the benefit-risk of using BIKTARVY during pregnancy and conception. An Antiretroviral Pregnancy Registry (APR) has been established. Available data from the APR for FTC shows no difference in the rates of birth defects compared with a US reference population.
• Lactation:?Women infected with HIV-1 should be instructed not to breastfeed, due to the potential for HIV-1 transmission.

U.S. Indication for Biktarvy Biktarvy is indicated as a complete regimen for the treatment of HIV-1 infection in adults and pediatric patients weighing at least 25 kg who have no antiretroviral (ARV) treatment history or to replace the current ARV regimen in those who are virologically suppressed (HIV-1 RNA <50 copies /mL) on a stable ARV regimen with no history of treatment failure and no known resistance to any component of Biktarvy. About Gilead Sciences Gilead Sciences, Inc. is a biopharmaceutical company that has pursued and achieved breakthroughs in medicine for more than three decades, with the goal of creating a healthier world for all people. The company is committed to advancing innovative medicines to prevent and treat life-threatening diseases, including HIV, viral hepatitis and cancer. Gilead operates in more than 35 countries worldwide, with headquarters in Foster City, California. For more than 30 years, Gilead has been a leading innovator in the field of HIV, driving advances in treatment, prevention, and cure research. Today, millions of people living with HIV globally receive antiretroviral therapy provided by Gilead or one of the company?s manufacturing partners. Forward-Looking Statements 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 possibility of unfavorable results from ongoing and additional clinical trials involving Biktarvy, and the possibility that we are unable to complete one or more of such trials in the currently anticipated timelines or at all. All statements other than statements of historical fact are statements that could be deemed forward-looking statements. 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 Annual Report on Form 10-K for the year ended December 31, 2020, 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. Prescribing Information for Biktarvy including?BOXED WARNING,?is available at?www.gilead.com.

Biktarvy, Gilead and the Gilead logo are registered trademarks of Gilead Sciences, Inc., or its related companies.

For more information about Gilead, please visit the company?s website at?www.gilead.com, follow Gilead on Twitter (@Gilead Sciences) or call Gilead Public Affairs at 1-800-GILEAD-5 or 1-650-574-3000.