MALVERN, Pa. and NEW YORK, Jan. 28, 2013 /PRNewswire/ -- Auxilium Pharmaceuticals, Inc. (NASDAQ: AUXL) ("Auxilium") and Xstelos Holdings, Inc. (OTCQB: XTLS) ("Xstelos") announced today that they filed a lawsuit against Upsher-Smith Laboratories, Inc. ("USL") for infringement of ten U.S. patents covering Testim, 1% testosterone gel, that are listed in the Approved Drug Products with Therapeutic Equivalence Evaluations (commonly known as the Orange Book), published by the U.S. Food and Drug Administration ("FDA"). These ten patents are owned by FCB I LLC, an indirect majority owned subsidiary of Xstelos, and are exclusively licensed to Auxilium. Xstelos holds the assets of CPEX Pharmaceuticals, Inc., the predecessor owner of the patents. The lawsuit was filed in the United States District Court for the District of Delaware on January 28, 2013. (Logo: http://photos.prnewswire.com/prnh/20101202/MM10881LOGO ) Auxilium and Xstelos filed this lawsuit in response to a notice letter sent by USL regarding its filing with the FDA of New Drug Application ("NDA") No. 204399 for a 1% testosterone gel product. This letter also stated that NDA No. 204399 contained Paragraph IV certifications, under 21 U.S.C. Section 314.52(c) of the Federal Food, Drug, and Cosmetic Act, with respect to the ten patents listed in the Orange Book as covering Testim: U.S. Patent Nos. 7,320,968; 7,608,605; 7,608,606; 7,608,607; 7,608,608; 7,608,609; 7,608,610; 7,935,690; 8,063,029; and 8,178,518. These ten patents are expected to expire on various dates ranging from April 21, 2023 through January 18, 2025. Auxilium and Xstelos remain committed to protecting their intellectual property rights, including their patent protection for Testim. Under the Hatch-Waxman Act, as a result of the patent infringement lawsuit filed against USL, final FDA approval of USL's NDA for its proposed generic version of Testim will be stayed until at least the earlier of 30 months from the date USL's notice letter was received ( i.e., June 24, 2015) or final resolution of the pending patent infringement lawsuit. While USL may receive tentative approval from the FDA for its version of Testim before one of those events occurs, it would not be permitted to launch its generic product in the U.S. until it receives the necessary final approval of its NDA from the FDA. About Auxilium Auxilium 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. About Xstelos Xstelos is a holding company formed for the purpose of holding the assets of CPEX Pharmaceuticals, Inc., an indirect, majority owned subsidiary of Xstelos. FCB I LLC is a wholly owned subsidiary of CPEX Pharmaceuticals, Inc. Subject to certain exceptions, including prior exemption by Xstelos' board of directors, Xstelos' Certificate of Incorporation prohibits and makes void ab initio certain transfers of its common stock, to the extent that after giving effect to such purported transfer (i) the purported transferee would become a 4.75% or greater holder of its common stock, (ii) the ownership of a 4.75% stock holder's common stock, prior to giving effect to the purported transfer, would be increased or (iii) the transfer creates a new "public group" under Treasury Section 1.382-2T(j)(3)(i).