SAN JOSE, Calif. — Liver specialist Maurizio Bonacini is in the race for a cure for hepatitis B, one of the world’s most widespread diseases and a top cause of liver cancer around the globe.

“It’s the last frontier,” said Dr. Bonacini, a San Francisco-based clinical researcher who has spent his career studying the chronic version of the disease estimated to affect more than 2 million people in the United States.

The World Health Organization estimates that one of three people worldwide has been infected by acute hepatitis B. The likelihood of developing chronic hepatitis B is higher for the young — the risk is 90% for babies with the bloodborne disease. When untreated, the virus progresses into liver cancer 25% of the time, killing one of four.

Although hepatitis B is both preventable with vaccines and treatable with oral medication, the virus continues to spread 60 years after its discovery. There is no cure yet.

Hoping to change this, Bonacini joined B-United, a clinical trial with 300 chronic hepatitis B patients at 80 sites across 18 countries, sponsored by GlaxoSmithKline, a biopharma company headquartered in the U.K.

Bonacini leads one of two investigation locations in California — the other is in San Jose, led by Dr. Huy A. Nguyen at San Jose Gastroenterology. Bonacini’s San Francisco site was first to treat a patient with a potential cure for chronic hepatitis B.

Until there’s a cure, patients with hepatitis B must take antiviral pills for life so the virus does not rebound. The medication stops the replication of hepatitis B DNA in the body, halving the risk of liver cancer and other complications. But the drugs can cause side effects such as upper respiratory infections, fatigue, nausea and gastrointestinal issues. Sometimes, people develop resistance to the antivirals, and in rare cases experience kidney or liver complications or failure.

“When we treat patients with hepatitis B, it’s like the Olympics. What we have now is the bronze medal,” Bonacini said.

Bonacini wants gold — a sterilizing cure that eradicates every trace of the virus and cannot return.

For now, he’ll take silver, a functional cure, one in which the virus could return, but which reduces cancer risk by 80% and allows patients to stop taking the antiviral pills.

Bonacini follows 10 Bay Area participants while observing 200 others under his care who could not qualify for the trial.

While still taking their regular medication, study patients receive monthly injections of an investigational drug that slows production of the surface antigen, the hallmark of the infection. After 24 weeks, they receive weekly injections of a different research drug for another 24 weeks. If surface antigens are still gone after 24 more weeks, patients stop all treatment but remain under close monitoring.

The U.S. Food and Drug Administration might consider the injections for market approval starting in late 2027, Bonacini said.

Bonacini emphasized the need for better prevention and diagnosis in the interim. This June, he asked more than 60 primary care physicians in California to flag state-mandated screening for hepatitis B in electronic health records systems. He said he received the pushback from the time-strapped practitioners.

“The consensus seemed to be that implementing this would be very burdensome. It takes time. I’ve been there,” he said.

Many of the doctors also did not want to make their patients take an additional test. “In theory, it should be covered (by insurance) in California, but the reality could be different,” he Bonacini.

Additionally, U.S. law requires proof of vaccination for immigrants entering the country, but not screenings. “That is a big mistake,” Bonacini said.

Even if a person shows proof of vaccination or receives one, vaccinations administered to those who are already infected don’t work.

The U.S. Citizenship and Immigration Services oversees immigration health requirements and designates doctors called “civil surgeons” to sign off on these requirements. The Centers for Disease Control and Prevention, which issues technical instructions for hepatitis B vaccines, confirmed that testing for the disease is not a part of protocol for civil surgeons because prospective immigrants would not be inadmissible — rejected from entry — for having the disease.

One of Bonacini’s study patients, a San Francisco resident in his 40s, slipped through this crack. He immigrated to the U.S. from Southeast Asia at age 9 and received a hepatitis B vaccination later as a student.

But after his first physical exam when he was in his 30s, he learned he had contracted hepatitis B before receiving the vaccination and now had fatty liver and mild cirrhosis.

He met Bonacini while volunteering for COVID vaccine studies and enrolled in the chronic hepatitis B cure research as soon as he became eligible.

Hepatitis B DNA became undetectable his system within months of taking oral medication; 26 weeks into trial injections, he is essentially noncontagious.

The man, who asked not to use his name because of the stigma around the condition, wishes more people talked more about hepatitis B. He’s speaking out more and finding others living with the condition. While glad to know he’s not alone, he is exhausted from maintaining his health under the ever-looming threat of liver cancer.

Every six months, he pays $100 to $200 for bloodwork and $500 to $700 for imaging before hitting his deductible. He said he can’t imagine the financial burden for those with inferior coverage.

“I’m getting used to it but there has to be a better way,” he said. “I will participate in any clinical trial just to find a cure.”

With better prevention, Bonaicini said we would rarely, if at all, see cases like this patient’s in a generation or two. But even then, a cure would still be necessary because it is impossible to inoculate every human.

As part of a global quest, he exchanges notes with respected virologists and clinicians in places like Tanzania and Hong Kong, where up to 7% of the population contends with the disease. He said studies increasingly suggest a cure is within reach.

“We just have to find the right drugs,” he said.

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