X0303 4 2011-06-21 0001097264 ALLOS THERAPEUTICS INC ALTH 0001215242 LEFF JONATHAN S 11080 CIRCLEPOINT ROAD SUITE 200 WESTMINSTER CO 80020 1 Stock Options (Right to Buy) 2.06 2011-06-21 4 A 0 20000 2.06 A 2012-06-21 2021-06-21 Common Stock 20000 20000 D Stock options vest according to the following schedule: The total number of shares subject to this option shall fully vest and become exercisable on the date of the next Annual Shareholder Meeting after the Grant Date, assuming continued service on the Board for such period. /s/ David C. Clark, Attorney-in-Fact for Jonathan S. Leff 2011-06-23