** Shares of Australian biotechnology firm Immutep IMM.AX rise as much as 22.2% to A$0.075, their highest since March 6
** Stock extends gain from the previous session when it closed 84.6% higher after receiving U.S. FDA Orphan Drug Designation for Eftilagimod Alfa to treat a type of cancer
** About 154.1 mln shares change hands, 3.1x the 30-day average of 50.2 mln
** Stock down 81.3% YTD, including current moves
(Reporting by Jasmeen Ara Shaikh in Bengaluru)
((Jasmeenaraislam.Shaikh@thomsonreuters.com;))