Achillion rises on study data for ACH-3102, part of a planned hepatitis C drug regimen

Achillion Pharmaceuticals climbed in premarket trading Friday after the company reported promising results from a small clinical trial of an experimental hepatitis C drug.

The drug, designated ACH-3102, is one half of a regimen that Achillion wants to begin testing on hepatitis C patients later this year. Shares of Achillion Pharmaceuticals Inc. jumped $1.55, or 18.4 percent, to $9.99 in premarket trading about 30 minutes before the market opening.

The company said all 12 patients in the clinical trial had undetectable levels of the hepatitis C virus after eight weeks of treatment with ACH-3102 and Gilead Sciences' drug Sovaldi. The virus was not detectable in the patients' bodies four weeks after their treatment ended. Based on the results, Gilead will test the drug combo on 12 more patients. Those patients will get the drugs for six weeks instead of 12 weeks.

Patients in the mid-stage study had been diagnosed with genotype 1 hepatitis C, the form of that disease that is considered the hardest to treat. They had not received any previous treatment and were given the drug regimen once per day.

The study is designed to give Achillion a better idea of how ACH-3102 might work with ACH-3422. That product is in early-stage testing, and Achillion plans to start a mid-stage study of the drug combination later this year. Patients in that trial will be treated for eight weeks or less.

Sovaldi was approved in December, and Gilead Sciences Inc. reported $3.48 billion in sales during the second quarter. Sovaldi has a success rate of better than 90 percent and it has fewer side effects than older hepatitis C treatments, but Gilead Sciences has also been criticized for the steep price of the drug, which comes to $1,000 per pill.