A simple antihistamine approved by the U.S. Food and Drug Administration 70 years ago may be an effective and affordable way to treat hepatitis C, new research shows.

Published today in the journal Science Translational Medicine, researchers from the National Institutes of Health (NIH) reported chlorcyclizine prevented hepatitis C infection in a petri dish and in humanized mice. They said it was effective and did not produce any significant cell toxicity when given along with existing drugs to treat hepatitis C.

But in stark contrast to existing hepatitis C drugs, which can cost $1,000 per pill, chlorcyclizine costs 50 cents per dose. The discovery could be a significant breakthrough in efforts to bring hepatitis C treatment to marginalized people around the world.

The antihistamine had a synergistic effect with FDA-approved hepatitis C drugs such as ribavirin, interferon, telaprevir, boceprevir, sofosbuvir (Sovaldi), daclatasvir, and cyclosporin A.

Many people with hepatitis C are having trouble accessing the latest generation of drugs. Sovaldi costs about $1,000 per pill but can cure the disease in 12 weeks. Many insurance companies won’t pay for the medication until a patient develops cirrhosis, or liver scarring.

Until new-generation drugs such as Sovaldi and Harvoni came to market in recent years, people underwent lengthy treatments with ribavirin, interferon, and other older drugs. The treatments caused unpleasant side effects and didn’t always work.

The new medications help prevent the virus from replicating, but the cost of the drugs is wreaking havoc on government-funded health programs, and many people with hepatitis C are unable to obtain the medications.

If chlorcyclizine is proven to work in humans, it could used either by itself or in conjunction with a less-expensive drug to combat hepatitis C.

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No Proof Yet Drug Works in People

The scientists in the new study used an automated drug screening process in a laboratory to test hundreds of drugs already approved by the FDA for other uses.

“This kind of work takes years,” said Dr. T. Jake Liang, one of the study co-authors. “We began over 10 years ago.”

Testing old drugs for new uses with high-throughput sequencing isn’t new. It allows scientists to identify drugs that could fall under the FDA’s “repurposing” requirements. This can allow fast-tracking for human trials.

“It cuts down the development process by many years, saving many millions of dollars,” said Liang, a senior investigator at the NIH’s Intramural Research Program. “And with more drugs, hopefully it drives prices down.”

Liang said human trials are already being planned using chlorcyclizine by itself and with ribavirin to treat hepatitis C.

Hepatitis C wasn’t identified until the early 1990s. Many people contracted the disease through a blood transfusion or from sharing a needle once. People still contract the disease regularly from sharing needles.

“We want to make sure that people understand that, while this is promising, people should not go out and take an antihistamine to prevent hepatitis C infections,” Liang stressed. “There are no proven benefits in people.”

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Americans with Hepatitis C Top 3 Million

It‘s estimated that more than 3 million people in the United States have hepatitis C. The Centers for Disease Control and Prevention (CDC) recommends all baby boomers get tested for it because hepatitis C damages the liver slowly, sometimes over the course of decades. People are often seriously ill by the time they learn they have it. Approximately one in three people infected with hepatitis C clear the virus without ever developing symptoms.

Dr. David Belk is a California physician board-certified in internal medicine and an expert on healthcare costs and pharmaceutical pricing. He cautioned the current research is preliminary, but it could offer good news if found effective in conjunction with a lower-priced medication such as ribavirin.

“We are hoping we can complement or supplement existing drugs and make them more accessible or less expensive,” Liang said.

But Belk said that, even in instances of repurposing like this, there are ways older medications can end up with price tags steeper than expected.

He noted that, for years, an inexpensive compound called colchicine was used to treat gout. But when it was proven effective in new trials paid for by a pharmaceutical company and then marketed with three years of exclusivity, the cost skyrocketed.

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