Astellas Milestone Deadline

Astellas Milestone Deadline. 5:00 p.m. Pacific time on the later of (i) March 31, 2012 or (ii) a date, the number of business days following March 31, 2012 equal to the number of business days elapsed between (A) August 31, 2011 and (B) the date on which the Company receives from the United States Food and Drug Administration approval of the Special Protocol Assessment for the Company's proposed phase 3 clinical trial of AC220 to the extent such date occurs following August 31, 2011.