Thallion Pharmaceuticals Inc. to Defer the Start Date of Its Phase II/III

Thallion Pharmaceuticals Inc. to Defer the Start Date of Its Phase II/III

MONTREAL, QUEBEC--(March 27, 2008) - Thallion Pharmaceuticals Inc. (TSX:TLN) today announced that it will defer the start date of its Phase II/III Shigamabs(R) clinical trial by an estimated six months based on both operational and strategic considerations. This decision allows Thallion to conserve existing capital and materially extend its development runway to advance other pipeline candidates. It also recognizes that given the seasonality of Shiga-toxin producing E. coli (STEC) infections, the period of high incidence in South America has now passed which would result in slower patient recruitment and higher costs per patient. The delay will also afford the Company time to continue its active discussions to secure a development and commercialization partner to assist in the further funding of the Shigamabs(R) program. The Company will focus its existing resources on its two primary oncology candidates which are expected to enter Phase II trials in the coming months.

"Deferring the start of the trial in South America will extend our existing cash runway by approximately six months, into the fourth quarter of 2009. Based on the other development opportunities we have available to us and the current climate of the capital markets, we took this fiscally responsible decision. We believe that if we can start the program later in the year, we can benefit from the South American summer and still maintain very similar timelines for a potential registration," said Lloyd M. Segal, Chief Executive Officer of Thallion Pharmaceuticals Inc. "Our decision takes into account the current macro financial environment, the strength of our balance sheet and our outlook for the overall sector in the near-term. From a scientific, clinical and regulatory perspective we continue to believe that STEC infection is a significant unmet medical need and that Shigamabs(R) provides a viable therapeutic approach with a clear path to global commercialization."

Thallion has received final regulatory approval from the respective regulatory agencies in both Argentina and Chile to begin a multinational Phase II/III Shigamabs(R) trial. The seasonal nature of STEC infections provide that incidences occur more frequently during the summer period, specifically from December through March in the southern hemisphere. Therefore, while Thallion has completed all the preparations for the initiation of the trial and the clinical sites are prepared to enroll patients, deferring the start of the trial will still enable the Company to capture the next peak season for STEC infections and optimize its spending on a per patient basis.

About Shigamabs(R)

Shigamabs(R) consists of two monoclonal antibodies designed to bind specifically and exclusively to the Shigatoxin 1 and Shigatoxin 2 toxins secreted by Shiga-toxin E. coli (STEC) bacteria. STEC infection is primarily a foodborne bacterial infection that causes serious health complications, particularly in young children and the elderly, and affects approximately 314,000 people annually in the industrialized world. There are no approved products available for the treatment of STEC infections. The Shigamab(R) 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(R) to address cases in which both Shigatoxins are present and also overcomes the inability of existing diagnostic technology to distinguish between cases caused by only one of the two toxins.

About Thallion Pharmaceuticals Inc.

Thallion Pharmaceuticals Inc. (TSX: TLN) is a biotechnology company developing pharmaceutical products in the areas of infectious disease and oncology. Thallion has three active clinical programs at a Phase II, or later, stage of development which include: Shigamabs(R), a dual antibody product for the treatment of Shigatoxin-producing E. coli bacterial infections; ECO-4601, a novel anticancer therapy derived from a nonpathogenic microorganism; and CAP-232, a targeted therapy with potential efficacy in multiple oncology indications. Additional information about the Company can be obtained at

Forward-Looking Statements

This press release contains certain forward-looking statements, including, without limitation, statements containing the words "believe", "may", "plan", "will", "estimate", "continue", "anticipate", "intend", "expect" and other similar expressions which constitute "forward-looking information" within the meaning of applicable Canadian securities laws. Forward-looking statements reflect the Company's current expectation and assumptions, and are subject to a number of risks and uncertainties that could cause actual results to differ materially from those anticipated. These forward-looking statements involve risks and uncertainties including, but not limited to, changing market conditions, the successful and timely completion of clinical studies, the establishment of corporate alliances, the impact of competitive products and pricing, new product development, uncertainties related to the regulatory approval process and other risks detailed from time-to-time in the Company's ongoing filings with the Canadian securities regulatory authorities which filings can be found at Given these risks and uncertainties, readers are cautioned not to place undue reliance on such forward-looking statements. The Company undertakes no obligation to publicly update or revise any forward-looking statements either as a result of new information, future events or otherwise, except as required by applicable Canadian securities laws.