Cancer Drug May Cure Hepatitis B

An antiviral and anti-cancer drug combination was 100% effective in preclinical trials.

An antiviral and anti-cancer drug combination was 100% effective in preclinical trials.

A cancer drug used in combination with an antiviral drug showed significant potential in curing hepatitis B virus (HBV) during a recent clinical trial.

The combination therapy, which involved the cancer drug birinapant with the antiviral drug entecavir, was 100% successful in curing HBV infection during hundreds of tests in preclinical models.

"Birinapant enabled the destruction of hepatitis B-infected liver cells while leaving normal cells unharmed,” study co-lead Marc Pellegrini, MD, said in a press release. “Excitingly, when birinapant was administered in combination with current antiviral drug entecavir, the infection was cleared twice as fast compared with birinapant alone. We are hopeful these promising results will be as successful in human clinical trials."

The combination therapy targets cell signaling pathways used by the hepatitis B virus to keep host liver cells alive. In chronic infectious diseases like HBV that live within host cells, these pathways enable the viruses to persist within the body for a long duration.

"Normally, liver cells would respond to infection by switching on a signal that tells the cell to destroy itself for the greater good, preventing further infection," Dr. Pellegrini said. "However, our research showed that the virus commandeers the liver cells' internal communications, telling the cells to ignore the infection and stay alive. Birinapant flips the cell survival switch used by the virus, causing the infected cell to die."

HBV, which infects liver cells and can lead to cirrhosis and liver cancer, results in more than 780,000 deaths annually, the study noted. Finding a treatment that allows the host cell to get rid of the virus, instead of targeting the virus itself, may stop drug-resistant strains of HBV from emerging, the researchers found.

"It is relatively easy for an organism to adapt to a drug, but it is very difficult to adapt to a change in the host cell," Dr. Pellegrini said. "The virus relies on the survival mechanisms of the host, so if it can't exploit them, it dies. Such a monumental change in the virus' environment may be too big a hurdle for it to adapt to."

The researchers will next evaluate whether this treatment strategy can be used in other chronic infectious diseases.

"Pathogens that infect and reside inside host cells, including viral diseases such as HIV, herpes simplex and dengue fever, and bacterial infections such as tuberculosis, could all potentially be cured in a similar way," Dr. Pellegrini concluded.