The marketing authorization allows for the marketing of TAF in the 28 countries of the European Union, Norway and Iceland.
University of Milan Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico Gastroenterology and Hepatology Division head Professor Pietro Lampertico said: “As the first new treatment for chronic hepatitis B to be approved in Europe in nearly a decade, this approval marks a step forward in the management of a progressive, life-threatening disease affecting 13 million Europeans.
“Treating a lifelong disease such as chronic hepatitis B can present challenges as patients age, and the improvements in bone and renal laboratory safety parameters demonstrated by TAF compared to TDF allow it to provide an important new option for patients.”
TAF is a novel, targeted prodrug of tenofovir that has demonstrated antiviral efficacy similar to Gilead’s Viread (tenofovir disoproxil fumarate, TDF) 245 mg, but at one-tenth the dose.
Data show that because TAF has greater plasma stability and more efficiently delivers tenofovir to hepatocytes (cells of the liver) compared to TDF, it can be given at a lower dose, which means there is less tenofovir in the bloodstream.
By reducing exposure to tenofovir, TAF is associated with improved renal and bone laboratory safety parameters compared to TDF in clinical trials.
Gilead Sciences executive vice president, research and development chief scientific officer Norbert Bischofberger, PhD said: “TAF reflects Gilead’s ongoing commitment to improve and simplify care for people with chronic infectious diseases, including hepatitis B, while we continue our research efforts for curative treatments.
“We look forward to making TAF available as quickly as possible throughout the European Union.”
TAF’s approval is supported by 48-week data from two international Phase 3 studies (Studies 108 and 110) in 1,298 adult chronic HBV patients. Study 108 randomized 425 HBeAg-negative patients to receive either TAF or TDF, and Study 110 randomized 873 HBeAg-positive patients to receive either TAF or TDF.
Both studies met their primary endpoint of non-inferiority to TDF based on the percentage of patients with chronic hepatitis B with plasma HBV DNA levels below 29 IU/mL at 48 weeks of therapy.
Patients in the TAF arm of the trials also experienced numerically higher rates of normalization of blood serum alanine aminotransferase (ALT) levels. Both studies showed TAF and TDF to be well-tolerated by patients and discontinuations due to adverse events were 1% and 1.2%, respectively.
The most common reported adverse events with TAF were diarrhea, vomiting, nausea, abdominal pain, abdominal distension, flatulence, fatigue, headache, dizziness, rash, pruritus, increased ALT and arthralgia.
While the primary efficacy assessment was performed at week 48, data show that at week 72 viral suppression as well as biochemical responses were maintained with continued TAF treatment.
The safety assessment includes analyses performed at both week 48 and week 72 of treatment (median duration of exposure of 88 weeks), and safety endpoints included changes from baseline in bone mineral density at the hip and spine, and changes from baseline in serum creatinine and in eGFR, key indicators of renal health.
In both studies, at weeks 48 and 72, changes in renal and bone laboratory safety parameters favored the TAF treatment groups.
Vemlidy was approved by the U.S. Food and Drug Administration on November 10, 2016 for the treatment of chronic HBV infection in adults with compensated liver disease, and by the Japanese Ministry of Health, Labour and Welfare on December 19, 2016 for the suppression of viral replication in chronic hepatitis B patients with evidence of hepatitis B virus replication and abnormal liver function.