Anadys Hepatitis C Drug Increases Punch Over Time (But So Does Placebo)
San Diego-based Anadys Pharmaceuticals reports that its hepatitis C drug appears to get better at wiping out the virus over time, although the company will have some explaining to do about why patients on a placebo appear to be doing almost as well.
Anadys (NASDAQ: ANDS) is announcing today that its lead product candidate, ANA598, when given in combination with standard therapies, was able to eliminate any sign of the liver-damaging virus in 73 percent of patients after 12 weeks. That’s more encouraging than an earlier snapshot, which showed the Anadys compound eradicated the virus in 56 percent of patients after four weeks.
Sounds great, but that’s not the end of the story. The control group of patients, who just got standard therapy and a placebo pill, saw their 12-week response rate climb to 71 percent, putting it almost on par with those who got the Anadys drug. Data was available from 26 patients who got a low dose of the Anadys drug taken twice daily, and 14 other patients in the control group.
The improvement in the control group was unexpected, and was most likely “an anomaly,” says CEO Steve Worland. Only half of the patients from the control group were analyzed, so the numbers were inflated when just a couple of patients saw significant improvement between weeks 10 and 12, Worland says. Historical studies suggest that by the time the most important data rolls in from this trial, after a full 24 weeks of observation, only about 45 to 60 percent of patients in the control group will likely have achieved undetectable levels of virus in the blood. If that’s the case in this study, that will show the advantage of ANA598 as long as it keeps the virus in check, Worland says.
“We’re happy with the results,” Worland says. “This is a clear signal for us to go ahead further in development. If people ask whether there’s an effect from ’598, it’s clear.”
What is encouraging in the data, Worland says, is that ANA598 showed greater viral-killing activity over time, the drug was well-tolerated, and researchers still haven’t seen any cases of the virus bouncing back, which some people have expected would happen with drugs in this class of non-nucleoside polymerase inhibitors. Based on the updated data, Anadys is resuming partnership talks with other companies that are seeking to change the standard of care for hepatitis C by combining cocktails of anti-viral drugs, as is done with HIV. Anadys is vying to provide a vital ingredient in the new treatment regimens for this chronic disease that affects an estimated 170 million people around the world.
As with any drug that might be taken by large numbers of people with a chronic disease, the safety profile is critically important. Anadys was previously dogged by worries about a link between its drug and rashes, so that’s one of the important questions to ask about the new 12-week data. About 41 percent of patients on the Anadys drug developed a rash, while 33 percent reported that effect in the control group. All of the rashes were mild, except one, which cleared up after the patients quit taking the Anadys drug, the company says. That one rash was classified as a Grade 3 side effect because the rash covered more than half of the patient’s body, but Worland noted that it didn’t cause blistering or ulcers.
Much more data is still to come throughout this year. Anadys enrolled another group of patients on a higher dose in this study, and expects to report how well that form of the treatment killed the virus in patients at the initial four-week observation point. Those results should be released before the end of March, and then the subsequent 12-week follow-up data from the group on the higher dose should be released before the end of June, Worland says.
Anadys plans to discuss the latest results in greater detail on a conference call with investors at 5 pm Eastern (2 pm Pacific) today. You can follow it via webcast at the Anadys company website.