XBiotech Enrolls First Patient in Phase III Pivotal Trial of Xilonix™

Trial Results to be Submitted For U.S. Marketing Approval Under FDA Fast Track Designation For Promising New Therapies

AUSTIN, Texas, Apr. 24, 2013 /PRNewswire/ -- XBiotech announced today enrollment of the first patient into its Phase III trial of Xilonix. The Pivotal study is designed to improve health and survival of late stage colorectal cancer patients with associated cachexia. The patient was enrolled by Dr. Eric Roeland at UC San Diego's Moores Cancer Center. The study is randomized to evaluate overall survival in patients treated with Xilonix and will be conducted initially in the United States before expanding elsewhere.  A total enrollment of approximately 650 patients is expected.  Study completion is anticipated in late 2014 with results potentially enabling marketing approval. XBiotech announced FDA Fast Track Designation for Xilonix in this indication at the end of last year.

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Xilonix is a first-in-class True Human™ antibody. The therapy is designed to block cancer-related chronic inflammation, thereby inhibiting tumor growth and metastasis—and the development of lethal complications from cancer such as cachexia.

Advanced refractory cancer patients treated in a previous clinical study at MD Anderson Cancer Center in Texas had longer than expected survival times. As well, in about one-third of all patients treated, there was a significant increase in lean body mass.  The majority of patients also reported a reduction in fatigue, as well as improved quality of life and function. In patients with advanced colorectal cancer, gains in body mass correlated with dramatic improvement in life expectancy.

"We are pleased to have reached this significant milestone and look forward to our continued progress toward the commercialization of our lead compound," said John Simard, president and CEO. "This is a very unique anti-cancer agent that we believe inhibits tumor growth and facilitates physical and emotional recovery from the disease. Xilonix has demonstrated the potential to prolong survival in patients considered refractory to all treatments. This represents a very important therapy."

About True Human™ Antibodies
True Human antibodies represent the next generation of therapeutic antibodies. True Human antibodies are "invisible" to the body's immune system and thus have the potential for better safety, efficacy and patient tolerability compared to earlier generation antibody therapeutics.

About XBiotech
XBiotech is pioneering breakthrough therapies that improve the safety and efficacy of antibody therapeutics. The Company's lead product candidate inhibits chronic sterile inflammation by targeting IL-1a, a master regulator of inflammation. The clinical development program addresses tremendous unmet medical need in multiple disease indications including, acne, psoriasis, cachexia, cancer, type 2 diabetes and cardiovascular disease. XBiotech is also revolutionizing scalable, flexible manufacturing systems for the production of biological therapies.  Using minimal infrastructure and disposable bioreactor technology – to dramatically reduce capital requirements, operating complexity, and lead times - the Company has established a compelling commercialization path for its True Human antibody platform.  XBiotech is building on a foundation of groundbreaking therapies, innovation and a commitment to unmet medical needs worldwide. For more information on how XBiotech is advancing human monoclonal antibody therapy please visit www.xbiotech.com.

Erika Geimonen, Ph.D.
[email protected]

Aaron DeLucia
Porter Novelli
[email protected]