Thallion Provides Update on Phase II SHIGATEC Trial

MONTREAL, QUEBEC--(Marketwire - July 13, 2011) - Thallion Pharmaceuticals Inc. (TSX:TLN) announced today that it has temporarily suspended the screening and enrollment of the high dose cohort of its Phase II SHIGATEC study as a precautionary measure due to a preliminary product out-of-specification ("OOS") finding observed during routine stability testing of its anti-Stx1 monoclonal antibody.

"This voluntary action reflects our uncompromising view towards the safety and care of our patients," commented Dr. Allan Mandelzys, Chief Executive Officer of Thallion. "Until we have more complete data to fully assess the situation, we determined that temporarily suspending enrollment is the appropriate and most conservative decision."

The company, together with its development partner LFB Biotechnologies, is conducting a thorough analysis to better understand the nature of this product OOS finding over the coming weeks and will communicate the results of its assessment promptly. Potential outcomes could range from removing the temporary suspension and continuing the study with the current clinical material or maintaining the enrollment suspension until a new lot of clinical material is manufactured.

About the SHIGATEC Trial

The randomized, double-blind, placebo-controlled trial will enroll 42 patients, aged six months to 18 years testing positive for STEC infection, distributed in two cohorts. The first cohort compares standard of care combined with a low dose of Shigamabs® (1 mg/kg/dose) versus standard of care with placebo. The second cohort will compare standard of care combined with a high dose of Shigamabs® (3 mg/kg/dose) versus standard of care with placebo. The primary endpoints for the Phase II trial are safety and tolerability. Secondary endpoints include pharmacokinetics and objective measures of efficacy using single and composite endpoints.

About Shigamabs®

Shigamabs® consists of two monoclonal antibodies designed to bind specifically and exclusively to the Shiga toxin 1 and Shiga toxin 2 toxins secreted by Shiga toxin- producing E. coli bacteria. STEC infections are primarily foodborne bacterial infections that cause serious health complications, particularly in young children and the elderly, and affect approximately 314,000 people annually in the industrialized world. There are no approved products available for the treatment of STEC infections. The Shigamabs® antibodies, administered as a single intravenous injection, bind to their respective toxin and neutralize them by forming a complex that is absorbed and destroyed by the liver and spleen. The dual antibody approach enables Shigamabs® to address STEC infections caused by E. coli secreting either Shiga toxin 1, Shiga toxin 2 or both Shiga toxins. Shigamabs® has obtained orphan drug designation both in the U.S. and in Europe.

About Thallion Pharmaceuticals Inc.

Thallion Pharmaceuticals Inc. (TSX:TLN) is a biotechnology company developing pharmaceutical products in the areas of infectious disease and oncology. The Company's clinical programs include Shigamabs® and TLN-4601, a novel anti-cancer therapy. Shigamabs® is a dual antibody product being evaluated in a Phase II clinical trial for the treatment of Shiga toxin-producing E. coli bacterial infections. Additional information about Thallion can be obtained at