Thallion Demonstrates ECO-4601 Crosses the Blood Brain Barrier and Selectively Targets Brain Tumours

MONTREAL, QUEBEC--(Nov. 29, 2007) - Thallion Pharmaceuticals Inc. (TSX:TLN) today announced that it presented data from a brain tumour model demonstrating that ECO-4601 crosses the blood brain barrier and preferentially targets and accumulates in glioblastoma (brain) tumours. These data also show that ECO-4601 binds in vivo to the peripheral benzodiazepine receptor (PBR), a receptor that is highly expressed in numerous cancer types, including glioblastoma.

"These results represent our first demonstration in vivo that ECO-4601 gets into the brain, binds to the PBR, and accumulates inside the tumour. These data corroborate the growing evidence suggesting that ECO-4601 is a dual active compound that both inhibits the Ras signaling pathway and binds to the PBR," said Lloyd M. Segal, Chief Executive Officer of Thallion. "There is still more work to be done, but the current evidence suggests that PBR may act as a molecular target for ECO-4601 and causes it to preferentially accumulate in tumours."

Thallion presented the research yesterday in a poster entitled, Targeted Delivery of ECO-4601 to Brain Tumors in an Orthotopic Model in San Francisco at the 3rd Modern Drug Discovery & Development Summit. In this brain tumour model, rat C6 glioma spheroids were surgically implanted into the brains of rats. Fourteen days after implantation, ECO-4601 was administered over a one-hour period and then measured. The level of ECO-4601 was 200 times higher in the tumour compared to the normal brain tissue and 11 times higher in the tumour compared to the plasma level. The average level of ECO-4601 in the tumour was 176 ug/g compared to an average of 0.807 ug/g in the brain and 16.2 ug/ml in the plasma. Dynamic Positron Emission Tomography (PET)-imaging studies using a radiolabeled PBR ligand were performed before and after ECO-4601 administration. The data show that ECO-4601 can effectively displace over 90% of the labeled molecule from the PBR in the tumour.

About ECO-4601

ECO-4601 is a novel small molecule derived from a nonpathogenic microorganism. It has demonstrated broad in vitro cytotoxic activity across a diverse panel of tumour cell lines and in vivo efficacy in a number of xenograft tumour models. Preclinical data suggest that ECO-4601 is a targeted anti-cancer agent with dual activity: selective binding to the peripheral benzodiazepine receptor (PBR) and inhibition of the Ras/MAPK pathway. ECO-4601 was discovered using DECIPHER®, Thallion's proprietary genomics-based drug discovery platform.

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®, a dual antibody product for the treatment of Shigatoxin-producing E. coli bacterial infections; ECO-4601, a novel anti-cancer 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 www.thallion.com.

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 www.sedar.com. 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.

For more information, please contact

Thallion Pharmaceuticals Inc. Michael Singer Chief Financial Officer 514-940-3600 514-228-3622 (FAX) info@thallion.com www.thallion.com

or

The Equicom Group Inc. Ross Marshall Investor Relations 416-815-0700 (Ext. 238) 416-815-0080 (FAX) rmarshall@equicomgroup.com

Posted: November 2007

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