Patients with chronic hepatitis B in Europe have gained the first new treatment option in nearly 10 years following the approval of Gilead's Vemlidy.

The active substance of Vemlidy is tenofovir alafenamide (TAF), a novel, targeted prodrug of tenofovir with high antiviral efficacy similar to Gilead's Viread (tenofovir disoproxil fumarate; TDF) at one-tenth of the dose. Because TAF enters cells more efficiently than TDF it can be given at a lower dose, massively reducing the amount of tenofovir present in the bloodstream.

According to Gilead, TAF also demonstrated in clinical trials improvements in surrogate laboratory markers of renal and bone safety compared to TDF, with patients experiencing a significantly smaller mean percentage decrease from baseline in hip and spine bone mineral density at week 48, highlighting further potential advantages.

More than 14 million people in Europe currently live with chronic hepatitis B infection and more than 1 million Europeans are newly infected with the virus each year.

Vemlidy's approval "marks a step forward in the management of a progressive, life-threatening disease," noted Professor Pietro Lampertico, head of the Gastroenterology and Hepatology Division at the University of Milan, Italy.

"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 allows it to provide an important new option for patients."

The once-daily pill is approved to treat the infection in adults and adolescents aged 12 years and older with body weight at least 35 kg.