About the IMPRESS Clinical ProgramAuxilium's late stage global development plan for XIAFLEX consists of four clinical studies and is known by the acronym IMPRESS – The I nvestigation for M aximal P eyronie's R eduction E fficacy and S afety S tudies. There are two randomized, double-blind, placebo-controlled phase III studies, which enrolled over 800 patients combined at 64 sites in the U.S. and Australia in less than five months, with a 2:1 ratio of XIAFLEX to placebo. There is also one open label study, which enrolled at least 250 patients, at approximately 30 sites in the U.S., EU and New Zealand, and one pharmacokinetic study, which enrolled approximately 20 patients who were then enrolled into the open label study. XIAFLEX was administered two times a week every six weeks for up to four treatment cycles (2 x 4). Each treatment cycle was followed by a penile modeling procedure. Patients were followed for 52 weeks post-first injection in the double-blind studies and will be followed for 36 weeks in the open label and pharmacokinetic trials.The trials' co-primary endpoints are percent improvement from baseline in penile curvature deformity compared to placebo and the change from baseline (improvement) in the PD bother domain of the PDQ compared to placebo. The PDQ also has two additional domains as secondary endpoints, which include severity of psychological and physical symptoms of PD, and penile pain. Safety measurements include adverse event monitoring and clinical labs. Immunogenicity testing was also performed. About the IMPRESS PDQThe PDQ is a 15-question assessment of the impact of PD on a subject using 3 domains: PD bother, psychological and physical symptoms of PD, and penile pain (at screening, week 24, and week 52). The PDQ is a proprietary questionnaire that Auxilium developed with the FDA following its phase IIb PD studies as a valid tool for measuring PD bother. About XIAFLEXXIAFLEX (collagenase clostridium histolyticum; CCH) is a biologic approved in the U.S. and the EU for the treatment of adult Dupuytren's contracture (DC) patients with a palpable cord. XIAFLEX is a minimally invasive treatment for this condition and consists of a highly purified combination of two subtypes of collagenase, derived from Clostridium histolyticum, in specific proportion. Together, the collagenase sub-types work synergistically to break the bonds of the triple helix collagen structure more effectively than human collagenase. XIAFLEX is currently in phase III of development for the treatment of Peyronie's Disease (PD). CCH is in phase IIa of development for the treatment of Frozen Shoulder syndrome (adhesive capsulitis) and in phase Ib of development for the treatment of cellulite (edematous fibrosclerotic panniculopathy). XIAFLEX has been granted Orphan status in the U.S. by the FDA for DC and PD. About AuxiliumAuxilium is a specialty biopharmaceutical company with a focus on developing and marketing products to predominantly specialist audiences. Auxilium markets Testim® 1% (testosterone gel) for the topical treatment of hypogonadism and XIAFLEX® (collagenase clostridium histolyticum) for the treatment of adult Dupuytren's contracture patients with a palpable cord in the U.S. GlaxoSmithKline LLC co- promotes Testim with Auxilium in the U.S. Ferring International Center S.A. markets Testim in certain countries of the EU and Paladin Labs Inc. markets Testim in Canada. Pfizer Inc. has marketing rights for XIAPEX® (the EU tradename for collagenase clostridium histolyticum) in 46 countries in Eurasia through April 24, 2013; Asahi Kasei Pharma Corporation has development and commercial rights for XIAFLEX in Japan; and Actelion Pharmaceuticals Ltd has development and commercial rights for XIAFLEX in Canada, Australia, Brazil and Mexico. The sBLA for XIAFLEX for the treatment of Peyronie's disease was submitted to the FDA on November 6, 2012 and has been accepted for standard review with a PDUFA date of September 6, 2013. Additionally, collagenase clostridium histolyticum ("CCH") is in phase IIa of development for the treatment of Frozen Shoulder syndrome (adhesive capsulitis) and phase Ib of development for the treatment of cellulite (edematous fibrosclerotic panniculopathy). Auxilium also has rights to pursue additional indications for CCH. SAFE HARBOR STATEMENT UNDER THE PRIVATE SECURITIES LITIGATION REFORM ACT OF 1995 This news release contains forward-looking statements as defined by the Private Securities Litigation Reform Act of 1995, including statements made with respect to Auxilium's strategy, progress and timing of development programs and related trials, the efficacy of its product candidates, the commercial benefits available to it as a result of its agreements with third parties, future operations, financial position, future revenues, projected costs, prospects, plans and objectives of management and other statements regarding matters that are not historical facts, and involve predictions. These statements involve known and unknown risks, uncertainties and other factors that may cause actual results, performance, achievements or prospects to be materially different from any future results, performance, achievements or prospects expressed in or implied by such forward-looking statements. In some cases you can identify forward-looking statements by terminology such as ''may'', ''will'', ''should'', ''would'', ''expect'', ''intend'', ''plan'', ''anticipate'', ''believe'', ''estimate'', ''predict'', ''potential'', ''seem'', ''seek'', ''future'', ''continue'', or ''appear'' or the negative of these terms or similar expressions, although not all forward-looking statements contain these identifying words. No specific assurances can be given with respect to: whether XIAFLEX will be the first and only approved biologic therapy indicated for the treatment of PD; the size of the potential market for XIAFLEX for the treatment of PD; whether XIAFLEX, if approved for the treatment of PD, has the clinical profile to become a potential breakthrough procedure, will be a successful treatment for PD or will lead to an evolution in the standard of care for PD; and whether XIAFLEX represents a pipeline in a product with potential applications in multiple therapeutic areas that currently have limited options. Although forward-looking statements are based on Auxilium's current plans or assessments that are believed to be reasonable as of the date of this press release, they inherently involve certain risks and uncertainties. These forward-looking statements are subject to a number of risks and uncertainties, including those discussed under ''Risk Factors'' in Auxilium's Annual Report on Form 10-K for the year ended December 31, 2011, each of Auxilium's Quarterly Reports on Form 10-Q for the three months ended September 30, 2012, June 30, 2012 and March 31, 2012 and Auxilium's preliminary prospectus supplement and Current Report on Form 8-K, each filed with the Securities and Exchange Commission (the "SEC") on January 23, 2013. While Auxilium may elect to update the forward-looking statements made in this news release in the future, Auxilium specifically disclaims any obligation to do so. Auxilium's SEC filings may be accessed electronically by means of the SEC's home page on the Internet at http://www.sec.gov. There may be additional risks that Auxilium does not presently know or that Auxilium currently believes are immaterial which could also cause actual results to differ from those contained in the forward-looking statements.