Cell Pathways and Bristol-Myers Squibb to Conduct Study in First-Line Non-Small Cell Lung Cancer.

Business Editors & Health/Medical Writers

HORSHAM, Pa.--(BW HealthWire)--May 3, 2001

Cell Pathways, Inc. (Nasdaq:CLPA) today announced that the company and Bristol-Myers Squibb Company plan to cooperate in supporting a clinical trial to study the combination of Aptosyn(TM) (exisulind) and TAXOL(R) (paclitaxel) plus Paraplatin(R) (carboplatin) as a first-line treatment for patients with advanced non-small cell lung cancer (NSCLC). This Phase I/II study is designed to evaluate escalating doses of Aptosyn(TM) in combination with a standard regimen of TAXOL(R) plus Paraplatin(R). The two companies intend to share the costs of this effort and share information.

The study will be conducted at Rush-Presbyterian-St. Luke's Medical Center in Chicago under the direction of principal investigator Dr. Philip Bonomi. Bonomi is director, Section of Medical Oncology and the Alice Wirtz Professor of Medicine at Rush Medical College. He is also co-chairman of NSCLC Studies, Eastern Cooperative Oncology Group Lung Steering Committee.

"Our selective apoptotic anti-neoplastic drugs (SAANDs), including Aptosyn(TM), have demonstrated synergistic anti-cancer effects in preclinical studies when combined with taxanes including TAXOL(R)," said Rifat Pamukcu, M.D., chief scientific officer of Cell Pathways. "The SAANDs also show at least additive activity with some other chemotherapeutic agents including certain platinum-containing compounds in preclinical studies. This new study extends the breadth of our current clinical investigations by using Aptosyn(TM) in combination with chemotherapeutic agents commonly used as first-line treatment in patients with NSCLC. This is an indication where current treatment options are limited, and it is our hope that this drug combination may eventually demonstrate improvement in survival in this high mortality disease."

Cell Pathways' lead drug candidate, Aptosyn(TM), is an investigational, oral agent that is designed to selectively trigger programmed cell death, or apoptosis, in precancerous and cancer cells via a mechanism of action different from currently marketed chemotherapeutic agents. The combination of Bristol-Myers Squibb's TAXOL(R) and Paraplatin(R) is the most commonly used regimen in community practice for the first-line treatment of NSCLC.

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 web site at http://www.cellpathways.com.

Certain statements in this release, and oral statements made with respect to this release, 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 and the need for further financing; early stage of development; the costs, delays and uncertainties inherent in science, basic pharmaceutical research, drug development, clinical trials and the regulatory approval process, with respect to both our current product candidates and our future product candidates, if any; dependence on the development and market acceptance of Aptosyn(TM) (exisulind) for one or more significant disease indications; 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; uncertainty of obtaining regulatory approval of any compound for any disease indication; uncertainty and adversity arising from the action of the U.S. Food and Drug Administration, or FDA, in issuing a "not approvable" letter with respect to the New Drug Application, or NDA, submitted for Aptosyn(TM) (exisulind) for the orphan drug condition of familial adenomatous polyposis, or FAP, a rare disease that puts those afflicted at high risk of developing colon cancer; the timing and scope of any approval which might be received, or any failure to receive approval, for any compound for any indication in the future; the volatility of the market price of our common stock; our ability to sell securities registered under the shelf registration statement; acceptance of any product candidates by physicians and providers of healthcare reimbursement; the actions of competitors; the pace of technological changes in the biopharmaceutical industry; dependence upon third parties; the validity, scope and enforceability of patents; the risk of our pending class action securities litigations; potential product liability claims; and availability of insurance. These and other risks are detailed in our reports filed from time to time under the Securities Act and/or the Securities Exchange Act, including the sections entitled "Business," "Risk Factors," "Management's Discussion and Analysis of Financial Condition and Results of Operations" and "Other Events" in our annual reports on Form 10-K, quarterly reports on Form 10-Q and periodic reports on Form 8-K and in such registration statements on Form S-3 as we may file from time to time. You are encouraged to read these filings as they are made. They are available over the Internet from the SEC in its EDGAR database at http://www.sec.gov and from the Company. Given the uncertainties affecting pharmaceutical companies in the development stage, you 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. No forward-looking statement can be guaranteed; actual future results may vary materially. Both forward-looking statements and statements of historic fact must be understood in the context of the risks referred to above which characterize our development-stage business. We undertake no obligation to update or revise the statements made herein or the risk factors that may relate thereto.

Note to Editors: Aptosyn(TM) is a trademark of Cell Pathways, Inc. TAXOL(R) and Paraplatin(R) are registered trademarks of Bristol-Myers Squibb Company.