CALGARY, Alberta, December 13, 2001 -- Oncolytics Biotech Inc. (TSE: ONC, NASDAQ: ONCY) (Oncolytics) announced interim results of its Phase I clinical trial of REOLYSIN®, a potential cancer therapeutic for RAS activated tumours and cancers.
The Phase I trial was designed as a dose escalation study to determine the safety and tolerance of REOLYSIN® in late-stage cancer patients who have failed all other treatment options. None of the patients to date have experienced any serious adverse events related to the virus nor were there any dose limiting toxicities detected in any patient. As secondary endpoints, Oncolytics measured tumour response at both the treated lesion as well as remote metastatic sites. Evidence of viral activity in tumours was observed, which ranged from changes in tumour structure to partial and complete tumour regression in the injected tumours. 50% of injected tumours in the first four of six groups (twelve of the eighteen patients) demonstrated evidence of viral activity. Preliminary evidence of remote tumour responses were also noted in the first four groups. 
“This positive data rewards the tremendous effort of everyone involved,” said Dr. Brad Thompson, President and CEO of Oncolytics. “Oncolytics is now in a position to initiate multiple follow up trials of REOLYSIN® to better determine its efficacy and safety profile. The first of these studies, a T2 prostate cancer trial, is expected to initiate enrollment in January of 2002. Other clinical trial protocols are being prepared. We are pleased that there appeared to be no safety issues with the administration of REOLYSIN® intratumourally, and with the treated lesion activity that has been observed to date.” 
The Phase I study enrolled a total of 18 patients in six groups of three patients each and examined intratumoural (into the tumour) administration of REOLYSIN®. The patients had a variety of primary cancers including breast, head and neck, melanoma, non-AIDS Kaposi’s sarcoma, and others. REOLYSIN® was administered directly into a subcutaneous (underneath the skin) tumour. None of the patients were screened for RAS activation of their tumours before entry into the trial.
Each group received increasing dosages of the virus. Dosages examined included single injections of 107, 108, 109, and 1010 PFU (plaque forming units, a measure of live virus particles), and multiple injections of 108and 109 PFU. The maximum dose tested in the trial was a single injection of 1010 PFU (virus particles). Both 108 PFU groups and the multiple 109 PFU group were added to the original study design when tumour activity was noted in the 107 PFU group, which was unexpected during the design of the study. Oncolytics had originally anticipated conducting groups at greater dosages using multiple injections of 1010 PFU but Oncolytics determined that it would not provide any more useful information for the future development of REOLYSIN®.

Detailed final results of this study are expected to be presented next year at an international cancer conference, and will include final safety, efficacy, and immune data on all the patients. 

About Oncolytics Biotech Inc.

Oncolytics is a Calgary-based biotechnology company focused on the development of the human Reovirus (REOLYSIN®), as a potential cancer therapeutic. Oncolytics researchers have demonstrated that the reovirus is able to selectively kill cancer cells and, in vitro, kill human cancer cells derived from many types of cancer including breast, prostate, pancreatic and brain tumours. Research has also yielded successful cancer treatment results in a number of animal models. In November of 2000, Oncolytics entered into a worldwide licensing agreement with Pfizer Inc. for the development and marketing of the reovirus for animal health applications.

This press release contains forward looking statements, within the meaning of Section 21E of the Securities Exchange Act of 1934, as amended. Forward looking statements, including the Company’s belief as to the potential of REOLYSIN® as a cancer therapeutic, the belief that the Ras pathway has broad potential in the treatment of many cancers; and the Company’s expectations as to the timing of the T2 prostate cancer trial, involve known and unknown risks and uncertainties, which could cause the Company’s actual results to differ materially from those in the forward looking statements. Such risks and uncertainties include, among others, the availability of funds and resources to pursue research and development projects, the efficacy of REOLYSIN® as a cancer treatment, the success and timely completion of clinical studies and trials, the Company’s ability to successfully commercialize REOLYSIN®, uncertainties related to the research and development of pharmaceuticals, uncertainties related to the regulatory process and general changes to the economic environment. Investors should consult the Company’s quarterly and annual filings with the Canadian and U.S. securities commissions for additional information on risks and uncertainties relating to the forward looking statements. Investors are cautioned against placing undue reliance on forward looking statements. The Company does not undertake to update these forward looking statements.