Shares of Achillion Pharmaceuticals (NASDAQ: ACHN ) are crashing 25% today after the company reported mixed early stage drug trial results yesterday and following Express Scripts‘ decision to remove Gilead Sciences‘ Harvoni
from its preferred drug formulary, a decision that may suggest future a
future price war among hepatitis C drug developers.
Why it’s happening
Achillion reported that its
promising hepatitis C drug, ACH-3102, cured 100% of patients when dosed
alongside Sovaldi for six weeks in a phase 2 trial, but that its Sovaldi
alternative, ACH-3422, posted a lower log reduction in viral clearance
during phase 1 studies than some had hoped.
The company is developing ACH-3102 as an alternative to Gilead
Sciences’ ledipasvir, which is paired up with Sovaldi in Gilead Sciences
latest generation hepatitis C drug, Harvoni. In November, Achillion
reported that 100% of patients taking ACH-3102 with Sovaldi for eight
weeks were free of the virus 12 weeks later, which is known as a
functional cure. The recent release demonstrating similar cure rates
four weeks after receiving the two drugs over a six week period may
suggest that ACH-3102 plus Sovaldi works as well as Harvoni with the
advantage of fewer weeks of treatment.