– Efficacy and Safety Profile of Once-Daily Vemlidy Demonstrated in Children Six Years of Age (Weighing at Least 25kg) and Older –

FOSTER CITY, Calif.--(BUSINESS WIRE)-- Gilead Sciences, Inc. (Nasdaq: GILD) today announced that the U.S. Food and Drug Administration (FDA) has approved the supplemental new drug application (sNDA) for Vemlidy® (tenofovir alafenamide) 25 mg tablets as a once-daily treatment for chronic hepatitis B virus (HBV) infection in pediatric patients six years of age and older and weighing at least 25 kg with compensated liver disease.

Vemlidy is a targeted prodrug of tenofovir that was approved by the FDA in 2016 as a once-daily treatment for adults with chronic HBV infection with compensated liver disease. In 2022, the FDA approved Vemlidy for the treatment of chronic HBV infection in pediatric patients 12 years of age and older with compensated liver disease. Vemlidy is recommended as a preferred or first-line treatment for adults with chronic HBV with compensated liver disease by the American Association for the Study of Liver Diseases (AASLD) and European Association for the Study of the Liver (EASL) guidelines.

“Chronic hepatitis B can have a significant and lasting impact on the health of children. If left untreated, hepatitis B can lead to liver cirrhosis and liver cancer,” said Chaun-Hao Lin, MD, Associate Professor of Clinical Pediatrics Krek School of Medicine of USC. “As a clinician, I am well aware of the critical importance of promptly treating this disease to avoid possible complications and liver damage. The clinical trial demonstrated that tenofovir alafenamide may represent an effective treatment option for children as young as six years old affected by this chronic disease.”

Vemlidy’s approval in this pediatric patient population is supported by Week 96 data from a Phase 2 clinical trial (Trial 1092) comparing treatment with Vemlidy 25 mg to placebo among 18 treatment-naïve and treatment-experienced patients aged 6 to less than 12 years weighing at least 25 kg (Cohort 2, Group 1). Participants in the Vemlidy group and in the placebo group who switched to open-label Vemlidy after Week 24 demonstrated progressive increases in the rates of virological suppression through Week 96 overall and within both study cohorts (children and adolescents).

“The expanded indication for Vemlidy for the treatment of children as young as six years old is a testament to the safety, tolerability and efficacy profile of this therapy,” said Frank Duff, MD, Senior Vice President, Virology Therapeutic Area Head, Gilead Sciences. “Effective and tolerable options for children require our best science and a dedicated focus. The work of our Gilead Pediatric Center of Excellence is responsible for coordinating pediatric clinical trials for treatments for cancer, HIV, hepatitis B, and COVID-19 and we will continue our research to help address unmet treatment needs for children.”

Vemlidy has a boxed warning in its product label regarding post-treatment severe acute exacerbation of hepatitis B. See below for important safety information.

U.S. IMPORTANT SAFETY INFORMATION AND INDICATION FOR THE USE OF VEMLIDY

BOXED WARNING: POSTTREATMENT SEVERE ACUTE EXACERBATION OF HEPATITIS B

Discontinuation of anti-hepatitis B therapy, including VEMLIDY, may result in severe acute exacerbations of hepatitis B. Hepatic function should be monitored closely with both clinical and laboratory follow-up for at least several months in patients who discontinue anti-hepatitis B therapy, including VEMLIDY. If appropriate, resumption of anti-hepatitis B therapy may be warranted.

Warnings and Precautions

• Risk of Development of HIV-1 Resistance in HBV/HIV-1 Coinfected Patients: Due to this risk, VEMLIDY alone should not be used for the treatment of HIV-1 infection. Safety and efficacy of VEMLIDY have not been established in HBV/HIV-1 coinfected patients. HIV antibody testing should be offered to all HBV-infected patients before initiating therapy with VEMLIDY, and if positive, an appropriate antiretroviral combination regimen that is recommended for HBV/HIV-1 coinfected patients should be used.
• 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. Patients with impaired renal function and/or taking nephrotoxic agents (including NSAIDs) are at increased risk of renal-related adverse reactions. Discontinue VEMLIDY in patients who develop clinically significant decreases in renal function or evidence of Fanconi syndrome. Monitor renal function in all patients – See Dosage and Administration.
• Lactic Acidosis and Severe Hepatomegaly with Steatosis: Fatal cases have been reported with the use of nucleoside analogs, including tenofovir disoproxil fumarate (TDF). Discontinue VEMLIDY 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 events in the week 96 pediatric population reported in ≥5% were: nasopharyngitis, headache, COVID-19, pyrexia, diarrhea, upper respiratory tract infection, cough, respiratory tract infection viral, abdominal pain upper. Overall, abdominal pain upper and metabolic nephropathy were the only study drug–related adverse events, which occurred in > 1 participant, reported in 2.3% (2/88 participants) each.

Drug Interactions

• Coadministration of VEMLIDY with drugs that reduce renal function or compete for active tubular secretion may increase concentrations of tenofovir and the risk of adverse reactions.
• Coadministration of VEMLIDY is not recommended with the following: oxcarbazepine, phenobarbital, phenytoin, rifabutin, rifampin, rifapentine, or St. John’s wort. Such coadministration is expected to decrease the concentration of tenofovir alafenamide, reducing the therapeutic effect of VEMLIDY. Drugs that strongly affect P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP) activity may lead to changes in VEMLIDY absorption.
• Coadministration of VEMLIDY with carbamazepine, the tenofovir alafenamide dose should be increased to two tablets once daily.

Consult the full prescribing information for VEMLIDY for more information on potentially significant drug interactions, including clinical comments.

Dosage and Administration

• Testing Prior to Initiation: HIV infection.
• Prior to or When Initiating, and During Treatment: On a clinically appropriate schedule, assess serum creatinine, estimated creatinine clearance, urine glucose, and urine protein in all patients. In patients with chronic kidney disease, also assess serum phosphorus.
• Dosage: 1 tablet taken once daily with food.
• Renal Impairment: Not recommended in patients with end-stage renal disease (ESRD; eCrCl