** Shares of Australia's Island Pharmaceuticals ILA.AX rise as much as 42.4% to record high of A$0.605

** Antiviral drug development co says it received positive responses from US Food & Drug Administration to questions on approval for co's antiviral drug - Galidesivir - and its eligibility for a priority review voucher (PRV)

** The priority review voucher, which has historically sold on the open market for between $100 mln and $155 mln, would boost Galidesivir's commercial value - co

** Co says FDA confirmed the Animal Rule pathway is appropriate for Marburg virus countermeasures, allowing approval based on animal efficacy data rather than human trials, accelerating approval timeline

** YTD, stock has more than tripled in value

(Reporting by Shruti Agarwal in Bengaluru)

((Shruti.Agarwal@thomsonreuters.com))