US immunology company Dynavax has finally secured approval from the US Food and Drug Administration (FDA) for its hepatitis B vaccine. Heplisav-B is the first new vaccine to be approved for the liver virus in more than 25 years and is the only two-dose hepatitis B vaccine offered for adults.

It was third time lucky for the company after the FDA had rejected two previous marketing applications in February 2013 and November 2016. It is also the first FDA-approved product for Dynavax.

Current hepatitis B vaccines require three shots over a six-month period, but nearly half of all adults fail to complete the course within one year, Dynavax said. Hepatitis B is an extremely infectious and potentially fatal virus with no cure, but the disease can be prevented through effective vaccination.

“Prevention of hepatitis B in adults through vaccination is more important than ever given the increase in the rate of infections,” said William Schaffner, professor of preventive medicine at Vanderbilt University Medical Center. “Too many at-risk adults remain unprotected against this virus. A two-dose schedule with higher rates of protection, along with other strategies, may help us move closer to the goal of eliminating hepatitis B as a public health problem in the United States.”

Heplisav-B’s approval was based on data from three Phase 3 trials, which showed a significantly higher rate of protection (95%) compared with GlaxoSmithKline’s (GSK) version, Engerix-B (81%).

Dynavax is also developing drug candidates for use in multiple cancer indications. Two of its lead candidates - cancer immunotherapies SD-101 and DV281 - are currently undergoing phase 1 and phase 2 studies.