Cell Pathways Contracts With Paladin Labs for Marketing and Distribution of Aptosyn in Canada.

Business Editors & Biotechnology/Pharmaceutical Writers

HORSHAM, Pa.--(BW HealthWire)--July 25, 2000

Cell Pathways, Inc. (Nasdaq:CLPA) today announced that the Company has signed a marketing and distribution agreement for Canada with Paladin Labs (TSE:PLB) of Montreal, Canada. The agreement provides Paladin Labs with exclusive rights to commercialize Aptosyn(TM) (exisulind) within Canada. The initial use of Aptosyn(TM) is expected to be for the treatment of precancerous colon polyps in patients with familial adenomatous polyposis (FAP). The terms of the agreement were not disclosed.

"Paladin has proven to be a leader in Canada in the commercialization of specialty medical products, with a strong track record of success in achieving regulatory approval and commercialization of innovative new drugs," said Robert Towarnicki, president and chief executive officer for Cell Pathways. "Paladin has also forged unique relationships with high prescribing physicians in a number of specialty markets. This should provide a strong foundation for marketing Aptosyn(TM) effectively, once Paladin achieves regulatory approval for the product in Canada."

"Paladin is excited to be working with Cell Pathways on the commercialization of Aptosyn(TM), which has shown promise in a broad number of important precancer and cancer indications," stated David MacNaughtan, Paladin's vice president, business development. "In addition to offering new hope for patients with FAP, Aptosyn(TM) has the potential to be a future great addition to our urology franchise for the treatment of prostate cancer."

Aptosyn(TM) is currently under review by the Food and Drug Administration in the United States for the prevention and treatment of precancerous colon polyps in patients with FAP. Cell Pathways is also conducting clinical investigations with Aptosyn(TM), both as a single agent and in combination with traditional chemotherapeutic agents, for the treatment and prevention of a variety of other cancers and precancerous conditions. A second SAAND compound, CP 461, is completing Phase Ib clinical safety testing in cancer patients.

Paladin Labs, headquartered in Montreal, Quebec, is a Canadian developer, marketer and distributor of innovative pharmaceuticals currently offering products in urology, dermatology, rheumatology and other specialty markets. For more information about Paladin, please visit the Paladin Web Site at www.Paladin-labs.com or send e-mail to [e-mail].

Cell Pathways, Inc., headquartered in Horsham, is a development-stage pharmaceutical company focused on the research, development and commercialization of novel and unique medications to prevent and treat cancer. For additional information on Cell Pathways, Inc., visit the company's website at http://www.cellpathways.com.

For Paladin Labs Inc.

The Toronto Stock Exchange has not reviewed and does not accept responsibility for the adequacy or accuracy of this release. This news release may contain forward-looking statements or predictions. These statements represent our judgement as of this date and are subject to risks and uncertainties that could cause actual results or events to differ materially from those expressed in such forward looking statements. Potential risks and uncertainties include, without limitation, those associated with product development, clinical trials, future revenues and profitability, and obtaining market approval.

For Cell Pathways, Inc.

Certain statements made herein, and oral statements made in respect hereof, constitute "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995. Such statements are those which express plan, anticipation, intent, contingency or future development and/or otherwise are not statements of historical fact. These statements are subject to risks and uncertainties, known and unknown, which could cause actual results and developments to differ materially from those expressed or implied in such statements. Such risks and uncertainties relate to, among other factors, the absence of approved products; history of operating losses; early stage of development; the costs, delays and uncertainties inherent in basic pharmaceutical research, drug development, clinical trials and the regulatory approval process, with respect to both the Company's current product candidates and its future product candidates, if any; dependence on development of Aptosyn(TM) (exisulind); the limitations on, or absence of, the predictive value of data obtained in laboratory tests, animal models and human clinical trials when planning additional steps in product development; the uncertainty of obtaining regulatory approval, including uncertainty of approval of the New Drug Application submitted for Aptosyn(TM) (exisulind) for familial adenomatous polyposis (a rare disease that puts those afflicted at high risk of developing colon cancer), whether in connection with the adequacy of the data generated in the clinical trials of Aptosyn(TM) (exisulind) or otherwise; the uncertainty of the effect of product approval, if achieved, on the market price of the Common Stock; the timing and scope of any approval which might be received for any compound for any indication in the future; acceptance by providers of healthcare reimbursement; the validity, scope and enforceability of patents; the actions of competitors; dependence upon third parties; product liability; and the need for further financing. These and other risks are detailed in the Company's reports filed from time to time under the Securities Act of 1933 and/or the Securities Exchange Act of 1934, including the sections entitled "Business," "Risk Factors," "Management's Discussion and Analysis of Financial Condition and Results of Operations" and "Other Events" in the Company's reports on Form 10-K for the year ended December 31, 1999, Form 10-Q for each of the first three quarters of 2000, Form 8-K for the month of August 1999, and Form S-3 filed in December 1999. You are encouraged to read these filings as they are made from time to time. They are available over the Internet from the SEC in its EDGAR database. Given the uncertainties affecting pharmaceutical companies in the development stage, current and prospective investors are cautioned not to place undue reliance on any such forward-looking statements, any of which may turn out to be wrong due to inaccurate assumptions, unknown risks, uncertainties or other factors. The Company undertakes no obligation to update or revise the statements made herein or the factors which may relate thereto.