Hepatitis C (HCV), the liver-damaging virus that affects about 33 percent of HIV-positive people, is tough to treat. The standard therapy (Pegasys plus ribavirin) takes about a year, works in only about a third of those with HIV and often causes unpleasant side effects. So, for some time now, newer classes of hepatitis meds have been badly needed. Good news: A front-runner in the development pipeline, telaprevir—a protease inhibitor for HCV—is steadily advancing.

In a recent Phase II trial, 65 percent of participants who added telaprevir to the standard hep C drugs for the first 12 weeks of treatment cleared HCV; only 45 percent of those taking just the standard drugs did. A bonus: In the telaprevir group, treatment time was cut from 12 months to six.

But there’s a catch. To date, telaprevir trials have excluded people with HIV. Theoretically, if approved, “telaprevir should increase cure rates for coinfected people,” says Daniel Raymond of the Harm Reduction Coalition, “though I doubt it will shorten the duration of their treatment.”

Hey, why not include HIV positive people in trials and find out?