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

Vemlidy's approval in this pediatric patient population is supported by 24-week data from a Phase 2 clinical trial (Trial 1092) comparing treatment with Vemlidy 25 mg to placebo among 70 treatment-naïve and treatment-experienced patients aged 12 to less than 18 years weighing at least 35 kg. The study met its primary endpoint of percentage of patients with HBV DNA levels below 20 IU/mL at 24 weeks of therapy; overall, 21% (10/47) of subjects treated with Vemlidy 25 mg achieved HBV DNA <20 IU/mL at 24 weeks compared to 0% (0/23) of subjects treated with placebo. 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.