A Phase II Study of DAS181, a Novel Host Directed Antiviral for the Treatment of Influenza Infection

Background. DAS181, a novel host-directed antiviral in development for influenza treatment, was assessed in this phase II clinical trial. Methods. This study was a double-blind, placebo-controlled phase II clinical trial assessing influenza viral load and patient safety in otherwise healthy influenza-infected participants. Participants were randomized to a single-dose, multiple-dose, or placebo group and were followed for safety and virologic outcomes. Results. A total of 177 laboratory-confirmed influenza-infected participants were enrolled in the trial, which encompassed 3 influenza seasons from 2009-2011 in both the Northern and Southern Hemispheres. Thirty-seven percent of participants had confirmed infection with influenza B, 33% with seasonal H3N2, 29% with pandemic 2009 H1N1, and 1 participant was positive for both influenza B and pandemic 2009 H1N1. Significant effects were observed in regard to decreased change from baseline viral load and viral shedding in the multiple-dose group compared with placebo as measured by quantitative polymerase chain reaction (P<.05). No instances of H274Y were observed among viral isolates from this trial. Overall, the drug was generally well tolerated. Conclusions. DAS181 significantly reduced viral load in participants infected with influenza, thus warranting future clinical development of this novel host-directed therapy.