FIRST AMENDMENT TO LICENSE AGREEMENT

EXHIBIT 10.11

FIRST AMENDMENT TO

LICENSE AGREEMENT

between

PHARMASSET, INC.

and

RFS PHARMA LLC

This First Amendment to License Agreement (“First Amendment”) is effective as of this 13 ^th day of February, 2006 (the “Effective Date”), by and between Pharmasset, Inc., a Delaware corporation having its principal place of business at 303-A College Road East, Princeton, New Jersey 08540 (“Pharmasset”), and RFS Pharma LLC, a Georgia limited liability company having its principal place of business at 2881 Peachtree Road N.E., Atlanta, Georgia 30305 (“RFSP”). Pharmasset and RFSP are each referred to individually as a “Party” and together as the “Parties.”

RECITALS:

WHEREAS, Pharmasset and RFSP are parties to a License Agreement, dated February 10, 2006 (the “Agreement”);

WHEREAS, Pharmasset and RFSP wish to amend the Agreement as set forth in this First Amendment.

NOW, THEREFORE, for good and valuable consideration, the