It seems Achillion Pharmaceuticals'
On Thursday, shares of the hepatitis C drugmaker fell more than 12% when Gilead Sciences
It didn't help; shares fell an additional 18%.
Taken alone, the data doesn't really look that bad. All 22 patients that completed the 24-week treatment with ACH-1625 had undetectable virus levels after the treatment. You can't get better than that.
The caveat comes back to why Achillion fell on Thursday; it's not developing a hepatitis C drug in a vacuum. In comparison to the other drugs, the ACH-1625 data isn't all that hot.
The 100% success rate isn't really a cure rate since the virus sometimes goes below the limits of detection, but then rebounds once the patient stops taking the drug. Gilead and Bristol's combination was measured four weeks after treatment ended, for instance. As Achillion continues following the patients, the rate could be reduced. The other problem with the 100% success rate is that it's measured for patients that saw their viral loads undetectable after the first 12 weeks of treatment. That's the correct way to run the trial -- there's no reason to continue treating if the drug isn't working -- but it means the cure rates of everyone treated will likely be lower.
More concerning is that ACH-1625 was tested in combination with a Roche's Pegasys (unlike the other hepatitis drug candidates). The future of hepatitis C treatment is an all-oral treatment that doesn't use Pegasys or Merck's
Of course, just because the drugs works in combination with Pegasys doesn't mean it won't work with other drugs. Achillion plans to combine ACH-1625 with one of its other hepatitis C drugs, ACH-3102. Unfortunately, ACH-3102 is further behind in the clinic and won't be ready for testing in combination until the fourth quarter.
Knocked down to a market cap less than $500 million, Achillion is cheap compared to the prices that Pharmasett and Inhibitex were taken out at. But any acquirer would likely want to see combination data, which is a year away and might be too late to the party. Achillion's best hope would be a stumble from the front runners, which would surely send its shares headed back up.