An experimental flu medicine from NexBio Inc. reduced the virus in patients’ blood by the second day of treatment, suggesting the drug may be an alternative to existing medications the virus has learned to evade. Patients given the therapy, dubbed DAS181, for three days also took less acetaminophen to reduce fever and symptoms than those given a placebo, according to study results presented at the Interscience Conference on Antimicrobial Agents and Chemotherapy in Chicago today. The 177-patient clinical trial is from the second of three phases of tests typically required for U.S. approval.