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PROTOX PRESENTS PORxin™ DATA AT INTERNATIONAL CANCER CONFERENCE

Vancouver, British Columbia, November 21, 2006 –Data supporting Protox Therapeutics Inc.’s (TSX-V: PRX) PORxin technology and its lead compound, PRX302, were presented during at the 18 th EORTC-NCI-AACR Symposium on “Molecular Targets and Cancer Therapeutics” held in Prague, Czech Republic, November 9 th & 10 th.

Dr. Sam Denmeade, Associate Professor of Oncology at Johns Hopkins University, reported results of pre-clinical studies showing that, when activated by the prostate specific antigen (PSA) enzyme, PRX302 was potentially effective in treating men with locally recurrent or advanced prostate cancer as well as those with BPH. Initial pre-clinical tests revealed that when the drug was injected into cancerous prostate tissue it had a significant effect.

“We injected either 0.35 or 4.1 micrograms as a single 25 microlitre injection where it resulted in destruction of either 25 or 50% of prostate tissue respectively,” said Dr. Denmeade. “This extensive damage was confined to the prostate with no toxicity observed in any other normal tissues, including those adjacent to the prostate such as the bladder, urethra, rectum and seminal vesicles. Furthermore, two weeks after the injection, we saw a disappearance of the toxin, but the continued presence of dead tissue, suggesting that the toxin’s effects could be long lasting.”

He added: “This represents a different kind of ‘targeted’ therapy, in that it seeks to use a protein made by the cancer to destroy itself.”

Protox is currently conducting Phase I clinical trials in prostate cancer using PRX302 and will commence a Phase I clinical trial for benign prostatic hyperplasia (BPH) in 2007.

To read the full press release go to http://www.fecs.be/emc.asp?pageId=1757

In a separate paper, Dr. Tom Buckley, Chief Scientific Officer of Protox disclosed the design of a new aerolysin variant, R336A, which is virtually stripped of its ability to bind to its natural receptor target, GPI-anchored proteins, found on the surface of human cells. By fusing IL2 with R336A, a highly selective and potent agent is created that has the potential to selectively seek out and bind to cells displaying the IL2 receptor and then to kill them by forming channels in their surfaces allowing the contents to leak out.

“By reducing or eliminating the natural binding ability of aerolysin and by engineering a targeting molecule, we have created a toxin that selectively targets cancer cells,” said Dr. Buckley. “The next step in developing our PORxin platform will be to determine which receptors associated with cancer cells represent the best targets and then to create new protease-activated PORxin molecules.

About Protox
Protox Therapeutics is a leader in advancing novel, targeted protein toxin therapeutics for treatment of cancer and other proliferative diseases. The company is actively developing two distinct but complementary platforms, INxin™ and PORxin™, and currently has three clinical programs in development. A Phase IIa clinical trial into the use of PRX321 (INxin) for the treatment of primary brain cancer has been completed and the drug has received Fast Track Designation and Orphan Drug Status from the US FDA. In addition, a Phase I trial has been completed for PRX321 to treat patients with renal cell carcinoma and non-small cell lung cancer. Patient enrolment is underway for a Phase I clinical study into the use of PRX302 (PORxin) to treat localized prostate cancer. PRX302 has also been approved by Health Canada to commence a Phase I clinical study for the treatment of benign prostatic hyperplasia.

NO REGULATORY AUTHORITY HAS APPROVED OR DISAPPROVED THE CONTENT OF THIS RELEASE. THE TSX VENTURE EXCHANGE DOES NOT ACCEPT RESPONSIBILITY FOR THE ADEQUACY OR ACCURACY OF THIS RELEASE.

Certain statements included in this press release may be considered forward-looking. Such statements involve known and unknown risks, uncertainties and other factors that may cause actual results, performance or achievements to be materially different from those implied by such statements, and therefore these statements should not be read as guarantees of future performance or results. All forward-looking statements are based on Protox’ current beliefs as well as assumptions made by and information currently available to Protox and relate to, among other things, anticipated financial performance, business prospects, strategies, regulatory developments, market acceptance and future commitments. Readers are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date of this press release.  Due to risks and uncertainties, including the risks and uncertainties identified by Protox in its public securities filings; actual events may differ materially from current expectations. Protox disclaims any intention or obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise.

For further information visit our website at www.protoxtherapeutics.com, or contact:

Anthony Boone
Director, Investor Relations and Corporate Communications
Protox Therapeutics
604-688-4369
aboone@protoxtherapeutics.com

Michael Moore
Investor Relations
The Equicom Group
416-815-0700 x 241
mmoore@equicomgroup.com