Gilead Sciences Sees Success With Flu Drug

Gilead and Roche have reported data from two Phase II studies whichdemonstrate that their orally-active neuraminidase inhibitor, GS 4104 (Ro 64-0796), is effective in the treatment and prevention of influenza A. The data were presented at the 37th Interscience Conference on Antimicrobial Agents and Chemotherapy in Toronto, Canada.

GS 4104 is a prodrug of GS 4017 which, while having broad-spectrum activity against various influenza strains, suffered from low oral bioavailability. In the prodrug form, the compound has been found to have between 11% and 73% bioavailability, depending on the animal model.

In the treatment trial, 80 volunteers were administered one of four doses (20mg bid, 100mg bid, 200mg bid or 200mg qd) of GS 4104 for five days or placebo 28 hours following intranasal exposure to influenza A. It was noted that GS 4104 significantly decreased the duration of influenza symptoms by around 50%, with the median time to symptom termination being 53 hours in the combined dose groups versus 95 hours in the control group. The time to symptom cessation tended to be lower in the higher-dose groups (a median of 47 hours for the 100mg bid, 200mg bid and 200mg qd groups, compared to a median of 94 hours in the 20mg bid group).