Around 70,000 people die each year from infections with the hepatitis E virus. There is currently neither a vaccine nor a specific drug against this virus. This could change with the identification of bemnifosbuvir as a compound effective against hepatitis E viruses (HEV). An international research team from Bochum, Germany, Heidelberg, Germany, and Beijing, China, has filtered this so called nucleotide/nucleoside analogue out of a library of such active substances. Since the drug is also effective against the hepatitis C virus and is already in clinical trials for this indication, the researchers hope that it could also become available as a treatment option against the hepatitis E virus in the foreseeable future. They report their findings in the journal “Gut” on March 6, 2026.

The starting point in the search for an active substance against HEV was a commercially available library of nucleotide/nucleoside analogues. “These synthetically produced molecules are constructed similarly to the building blocks of our genetic material and likewise to that of viruses,” explains Dr. Mara Klöhn from Ruhr University Bochum.

To find out whether any of the roughly 500 compounds in the library could inhibit HEV replication, the researchers used a new reporter virus that contained a fluorescent molecule. They infected cell cultures with hepatitis E viruses that carried this reporter gene and then added the various candidate compounds. Using fluorescence, they were able to determine whether the virus had continued to replicate or not. “With bemnifosbuvir we were able to see that the virus no longer replicated, while the treated cells remained healthy,” reports Jungen Hu from Heidelberg University. In animal experiments, the Chinese researchers were able to confirm the efficacy of the substance against HEV and liver inflammation. “If the ongoing clinical trials of bemnifosbuvir against hepatitis C are successful, the drug could soon also be available for off label use against hepatitis E,” say Dr. Viet Loan Dao Thi and Professor Eike Steinmann.

The hepatitis E virus (HEV) is the main cause of acute viral hepatitis. Around 70,000 people die from the disease each year. After the first documented epidemic outbreak in 1955 to 1956, it took more than 50 years before researchers began to study the topic intensively. Acute infections usually resolve spontaneously in patients with an intact immune system. In people with a reduced or suppressed immune system, such as organ transplant recipients or individuals with HIV, HEV can become chronic. HEV is also particularly dangerous for pregnant women. There is no vaccine and no specific drug.