For decades, people infected with hepatitis C virus (HCV) have had to endure painful treatment regimens, including injections of the drug interferon, which can lead to severe nausea and depression. But with the upcoming approval of several highly effective oral antiviral drugs, and more in development, researchers say eradicating HCV infection worldwide is now a very realistic goal. Unlike previous HCV treatments – which sought to boost the immune system with interferons and other drugs – this latest group of oral drugs disrupts the virus’ ability to replicate and synthesize proteins. A U.S. Food and Drug Administration (FDA) committee recently recommended two such drugs – New Jersey-based Johnson & Johnson’s simeprevir and California-based Gilead Sciences’ sofosbuvir – for approval to market. When each drug is used in combination with a separate drug called ribavirin, it can treat about 80 percent of patients with hepatitis C. ”For the first time in human history, we are able to cure a viral disease,” said Raymond Schinazi, a pharmacologist at Emory University in Atlanta, Georgia. Findings from the trials of different drug combinations were released last week. One of the phase II trials, called COSMOS, tested the results of a combination of sofosbuvir and simeprevir in 197 people with HCV infection – patients who either did not respond to interferon or developed advanced liver fibrosis from the virus. And after 12 weeks of treatment, both drugs completely cleared HCV in more than 90 percent of the patients. And another study led by Kazuaki Chayama, a physician at Hiroshima University in Japan, using daclatasvir and asunaprevir – developed by Bristol-Myers Squibb in New York Another study led by Kazuaki Chayama, a physician at the University of Tajima, treated 220 people with a combination of daclatasvir and asunaprevir, two new drugs developed by Bristol-Myers Squibb in New York. This “cocktail” cured 85 percent of people infected with HCV. Eric Hughes, who leads the company’s global medical research staff, said they intend to submit the drugs to the FDA in 2014. Despite these encouraging results, larger combination studies involving multiple drug companies seem unlikely. Charlotte Edenius, vice president of development at Medivir, a Stockholm, Sweden-based drug company that has worked with Johnson & Johnson in the COSMOS study, said Johnson & Johnson and Gilead Sciences do not intend to conduct a joint Phase III clinical trial. Similarly, a spokeswoman for Bristol-Myers Squibb said the company no longer plans to conduct a larger sofosbuvir-daclatasvir combination trial with Gilead Sciences, even though the paired drugs cured all 41 patients in a Phase II clinical trial completed earlier this year. Even without a phase III clinical trial or FDA approval of these therapies, Johns Hopkins University in Baltimore, Md. David Thomas, a hepatitis C researcher at Johns Hopkins University in Baltimore, Maryland, also expects that some doctors will begin prescribing such “unconventional” combinations of drugs for refractory cases. Thomas also said that the impressive cure rates achieved in clinical trials mean that the combination of these potent drugs could eradicate HCV worldwide – at least in theory. The virus does not have an animal host, meaning it is not hidden by other animals and is not easily transmitted from person to person, except through the bloodstream. Over the past 15 years, improved techniques for screening the blood supply for transfusions, as well as better patient screening, have dramatically cut the rate of hepatitis C. Thomas stressed that the emergence of drug-resistant strains of the virus may be a barrier, but they can be very rare because the latest antiviral drugs are so powerful when used in combination. Yet Rajender Reddy, a hepatologist at the University of Pennsylvania in Philadelphia, sees another stumbling block: how to get them to the people who need them. Many of the roughly 170 million people worldwide with HCV infection may not be able to afford these drugs, he says. And drug companies also lack the incentive to reduce costs – unlike antiviral treatment for HIV, which requires only 12 weeks of dosing, HCV treatment requires a lifetime of dosing.