CUSIP No. 03152W109

13G

Page 8 of 12 Pages

David J. Morrison (“Morrison”) is the record owner of 57,802 shares of Common Stock (the “Morrison Shares”). Great Point is the investment manager with respect to the Morrison Shares, and by virtue of such status may be deemed to be the beneficial owner of the Morrison Shares. Each of Dr. Jay, as senior managing member of Great Point, and Mr. Kroin, as special managing member of Great Point, has voting and investment power with respect to the Morrison Shares, and therefore may be deemed to be the beneficial owner of the Morrison Shares. In addition, Morrison is the record owner of a warrant to purchase 28,901 shares.

The warrants described above are not exercisable until September 9, 2010. As a result, the reporting persons disclaim beneficial ownership of the shares underlying the warrants until 60 days prior to such date. In addition, the provisions of such warrants restrict the exercise of such warrants to the extent that, after giving effect to such exercise, the holder of the warrants and its affiliates and any other person or entities with which such holder would constitute a group would beneficially own in excess of 9.99% of the number of shares of Common Stock of the Issuer outstanding immediately after giving effect to such exercise (the “Ownership Cap”). Accordingly, sixty days prior to the warrants becoming exercisable, the reporting persons may be deemed to become the beneficial owners of such additional number of shares underlying such warrants, which together with the shares currently owned, would result in beneficial ownership by the reporting persons of such number of shares equal to the Ownership Cap.

Notwithstanding the above, Great Point, Dr. Jay and Mr. Kroin disclaim beneficial ownership of the BVF Shares, the BOVF Shares, the BIVF Shares, the Lyrical Shares, the GEF-PS Shares, the Morrison Shares and the shares underlying the warrants described above, except to the extent of their respective pecuniary interests.

Provide the following information regarding the aggregate number and percentage of the class of securities of the issuer identified in Item 1.

1.

Great Point Partners, LLC

(a)

Amount beneficially owned: 6,360,349³

(b)

Percent of class: 9.99%^{3, 4}

³

Consists of 1,626,705 shares owned by Biomedical Value Fund, LP (“BVF”), 1,830,718 shares owned by Biomedical Offshore Value Fund, Ltd. (“BOVF”), 532,986 shares owned by Biomedical Institutional Value Fund, LP (“BIVF”), 867,052 shares owned by Lyrical Multi-Manager Fund, LP (“Lyrical”), 1,445,086 shares owned by Class D Series of GEF-PS, LP (“GEF-PS”) and 57,802 shares owned by David J. Morrison (“Morrison”). Does not include 704,856 shares underlying a warrant held by BVF, 765,384 shares underlying a warrant held by BOVF, 205,862 shares underlying a warrant held by BIVF, 433,526 shares underlying a warrant held by Lyrical, and 722,543 shares underlying a warrant held by GEF-PS and 28,901 shares underlying a warrant held by Morrison. The warrants are not exercisable until September 9, 2010. As a result, the reporting persons disclaim beneficial ownership of the shares underlying the warrants until 60 days prior to such date. In addition, the provisions of such warrants restrict the exercise of such warrants to the extent that, after giving effect to such exercise, the holder of the warrants and its affiliates and any other person or entities with which such holder would constitute a group would beneficially own in excess of 9.99% of the number of shares of Common Stock of the Issuer outstanding immediately after giving effect to such exercise (the “Ownership Cap”). Accordingly, sixty days prior to the warrants becoming exercisable, the reporting persons may be deemed to become the beneficial owners of such additional number of shares underlying such warrants, which together with the shares currently owned, would result in beneficial ownership by the reporting persons of such number of shares equal to the Ownership Cap.