BOSTON (TheStreet) -- Sorry to play the Scrooge in front of Christmas, but the data released Monday on Achillion Pharmaceuticals' (ACHN) hepatitis C "nuc" ACH-3422 falls short of spectacular. Tamp down your hopes and dreams if you were expecting Achillion to be the next hepatitis C buyout candidate.
Achillion shares are up 18% to $16.84.
The efficacy bar for ACH-3422 was a 4-log reduction in viral load after seven days of dosing in genotype 1 hepatitis C patients. Achillion fell short, achieving a 3.4-log reduction at seven days with the highest, 700 mg dose of '3422.
Achillion decided to extend treatment for another week. After 14 days, the 700 mg dose of ACH-3422 demonstrated a 4.8-log reduction in viral load. Three of the six patients treated had hepatitis C virus that was undetectable in their system at the end of the 14 days.
These Achillion results aren't great because the speed at which drugs kill the hepatitis C virus matters. Slower-acting drugs leave patients vulnerable to viral rebound or relapse. Gilead Sciences' (GILD) Sovaldi -- the only approved hepatitis C "nuc" on the market -- and Merck's (MRK) MK-3682, the still-experimental nuc acquired through the purchase of Idenix Pharmaceuticals -- both achieved larger viral load reductions faster than Achillion's ACH-3422.
It's also noteworthy -- and concerning -- that Achillion need to dose up to 700 mg of ACH-3422 in order to achieve a 4-log reduction in viral load. The company hoped to see better results with a 400 mg dose of the drug.