Attention Cell Pathways CLPA Investors.

ATLANTA--(BUSINESS WIRE)--March 16, 1999--Notice is hereby given that Chitwood & Harley has filed a class action lawsuit in the United States District Court for the Eastern District of Pennsylvania on behalf of all purchasers of the common stock of Cell Pathways, Inc. ("Cell Pathways" or "Company") between November 3, 1998 and February 2, 1999, inclusive (the "Class Period"), as well as on behalf of all former Tseng Labs, Inc. shareholders who acquired Cell Pathways common stock pursuant to the Joint Proxy Statement and Prospectus dated September 22, 1998.

The complaint alleges that Cell Pathways and certain of its officers and directors violated Sections 10(b) and 20(a) of the Securities Exchange Act of 1934 and Section 11 of the Securities Act of 1933. The complaint alleges that defendants issued a series of materially false and misleading statements concerning the discovery of Cell Pathways' new drug, PREVATAC, the progress and efficacy of PREVATAC, as well as Cell Pathways' projected growth. The complaint further alleges that due to the issuance of these false and misleading statements, the price of Cell Pathways' common stock was artificially inflated during the Class Period.

Furthermore, the complaint alleges that on February 1, 1999, after the close of trading, the Company disclosed that, among other things, a preliminary evaluation of clinical trials of PREVATAC did not achieve a statistically significant clinical response when compared to a placebo, and as a result, Cell Pathways would not be making its anticipated New Drug Application filing in March of 1999. The complaint further alleges that as a result of this announcement, the price of Cell Pathways' stock collapsed from a Class Period high of more than $29 per share to $6 per share.

Plaintiff is represented by Chitwood & Harley, an Atlanta law firm that concentrates its practice in representing victims of securities fraud and corporate mismanagement as well as other complex litigation. The firm has been appointed lead counsel in several major actions pending in both federal and state courts and has been instrumental in recovering millions of dollars on behalf of investors and shareholders.

Any member of the proposed class who wishes to move the court to serve as lead plaintiff of the Class must do so no later than 60 days from February 12, 1999. In order to serve as lead plaintiff you must meet certain legal requirements.

If you wish to discuss this action or have any questions concerning this notice or your rights with respect to this matter, you may contact Corey D. Holzer, by telephone [phone] (toll-free), Chitwood & Harley, 2900 Promenade II, 1230 Peachtree Street, N.E., Atlanta, GA 30309. Please visit our website at www.classlaw.com.