Three quarters of people with hepatitis C virus (HCV) who took a regimen including the experimental drug telaprevir managed to clear the virus with just six month's of treatment, according to a release from the drug's developer, Vertex Pharmaceuticals, and reporting by The New York Times. Though the study only included HIV-negative people, it was conducted in people with a difficult-to-treat strain of HCV—genotype 1—and the results offer real promise that the drug could substantially increase cure rates in people infected with both HIV and HCV.

HCV treatment, when it is successful, manages to permanently clear the virus from the body. In other words, it appears that people who maintain undetectable HCV levels for months or years after completing a course of treatment are cured of the virus. Unfortunately, cure rates are significantly lower in people with the genotype 1 and lower still in people coinfected with both HCV and HIV. Thus, deciding when and whether to start HCV treatment is often a difficult decision for coinfected individuals. Should they undergo 48 weeks of a frequently debilitating and toxic HCV treatment for what is usually a less than 25 percent chance of a cure?

Answering this question might get easier in the next couple of years. New treatments are rapidly nearing approval that might improve cure rates for all people with HCV, and achieve a cure in only 24 weeks, as opposed to 48 weeks. One of those treatments is telaprevir.

The newly reported data showed that 75 percent of those who added 12 weeks of telaprevir to standard HCV treatment—pegylated interferon and ribavirin—achieved and maintained undetectable HCV levels for six months after completing their course of treatment (called a sustained virological response, or SVR).  Intriguingly, 69 percent of those who added telaprevir for only eight weeks also achieved an SVR. Meanwhile, only 44 percent of those on standard treatment alone achieved an SVR after a full 48 weeks of treatment. Among those who received either 8 or 12 weeks of telaprevir, the majority were treated for only 24 weeks with standard therapy.  

Studies have already begun to test whether telaprevir improves cure rates in people coinfected with both HIV and HCV. It will be at least a year or two before we know definitely whether adding telaprevir increases SVRs in coinfected individuals. Nevertheless, the Times reports that the cure rates in the newly reported telaprevir studies are at least as good, if not better, than the company's original expectations, adding, “Experts say the results could herald a new era in treating a sometimes fatal disease that is often overlooked, despite afflicting as many as 3.9 million Americans and 170 million people worldwide.”

Responding to the news of the study, Scott Friedman, the chief of the division of liver diseases at Mount Sinai School of Medicine in New York City, told the Times, “If you can promise [patients] six months with a reasonable chance of a cure, that's a meaningful advance.”