Drug raises hope of ‘functional cure’ for hepatitis B patients

HKU plans regional testing of medicine believed to have suppressed viral load in 1 in 10 sufferers

Researchers at the University of Hong Kong (HKU) believe they have freed one in 10 hepatitis B patients from the need for lifelong treatment and the risk of liver cancer, thanks to a new drug.

Following clinical trials in the city, the team aimed to test the drug in the region and hoped to achieve a 30 per cent success rate, said Yuen Man-fung, chair professor and chief of the division of gastroenterology and hepatology at the university’s medical faculty.

Yuen added it was still impossible to eliminate the hepatitis B virus, but the drug helped patients achieve a “functional cure”, suppressing their viral load to an undetectable level.

“Hepatitis B virus is one of the smartest viruses in the world. A protein on its surface, which we call surface antigen, could put your immune system to sleep,” said Yuen, chief inspector of the research.

“Our drug serves the function of awakening your immune system, so it can act against the virus on its own.”

The HKU team of eight investigators, including Yuen, first started testing the drug in 2017. Their findings were published last month in the New England Journal of Medicine.

Describing their efforts as a breakthrough, Yuen said the findings were well received by international experts, including those at a meeting he attended in the United States last month.

About 7.8 per cent of the city’s population, or 570,000 people, are infected with hepatitis B, but most only find out when it progresses to liver cirrhosis or cancer.

Current treatments can lower the chances of complications and death, but patients must take their medicines for life.

Some drugs help patients achieve a functional cure after three to seven years, but the success rate has been low.

Yuen and his team aimed to develop a drug to suppress the virus over the long term, with treatment lasting no longer than two years, so that patients could stop taking medicines with minimal risk of relapse.

They began testing the drug in 2017 at Queen Mary Hospital. In the second phase of clinical trials from 2020 to this year, 457 patients were given a weekly injection of the drug for six months.

The virus was not detectable in about 9 per cent to 10 per cent of the patients over the following six months. Among some elderly patients, whose immune system was less affected by the virus, the success rate ranged from 16 per cent to 25 per cent.

No significant side effects were observed except injection pain.

Although they were monitored for only six months after treatment, Yuen said their low viral load would possibly last for good, unless they underwent other treatments which suppressed the immune system.

“Although we have achieved a 10 per cent success rate, we will not stop here,” Yuen said. “In the third phase of clinical trials we will combine the treatment with other drugs, like a cocktail therapy.”

The team is working towards 30 per cent success, a target accepted by international experts.

The third phase of clinical trials will involve a few hundred patients across multiple Asian countries with a high hepatitis B infection rate.

Yuen expected the drug to become available in three to five years.

Health authorities previously aimed to eliminate viral hepatitis as a public health threat by 2030, a goal of the World Health Organization.

That would need a 90 per cent diagnosis rate, 80 per cent treatment rate, a 90 per cent reduction in new cases, and 65 per cent reduction in deaths.

However, Yuen said it would be impossible for the city to achieve that target without universal screening for patients.

He suggested that people with a family history of liver disease and those born before 1988, the year when all newborn babies began receiving the vaccine at birth, should get priority in screening.

Those who pass the screening but are not yet vaccinated should get their jab.

Yuen said the city’s primary healthcare system had a crucial role to play in the prevention and treatment of hepatitis B.

“At Queen Mary Hospital alone, we are seeing up to 400 hepatitis B patients every single week,” he said. “If we identify all the 570,000 patients in Hong Kong, how can our medical system accommodate them?”

He said the steering committee on prevention and control of viral hepatitis, an official panel, had been in talks with family doctors to equip them with knowledge to treat the infection in the community.

Our drug serves the function of awakening your immune system so it can act against the virus on its own

YUEN MAN-FUNG, UNIVERSITY OF HONG KONG