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Supplemental Proxy Materials
filed pursuant to Rule 14a-2
under the Securities Exchange
Act of 1934
[TSENG LETTERHEAD] October 15, 1998
Dear Tseng Labs, Inc. Stockholder:
You are cordially invited to attend a 30 minute luncheon presentation by the
Cell Pathways, Inc. management team with respect to the Cell Pathways/Tseng
transaction and the business of Cell Pathways at the following locations:
City Date and Time Location Call
- ---- -------------- --------- -----
San Francisco Wednesday, Salomon Smith Barney Helen Kim
October 21 39th fl. 415-955-1605
12:30 p.m. 555 California Street
Chicago Friday, Salomon Smith Barney Kathy Boyer
October 23 87th fl. 312-419-3627
12:15 p.m. Sears Tower
New York City Tuesday, The Omni Berkshire Stacey Alosa
October 27 Hotel 212-723-7297
12:00 p.m. Carnegie Room
21 East 52nd St.
Philadelphia Thursday, The Pyramid Club Bill Freeman
October 29 52nd fl. 215-854-6034
12:00 p.m. Mellon Bank Center
1735 Market St.
You should have already received proxy materials with respect to the November 3
special meeting of stockholders of Tseng Labs, Inc. to consider the proposed
transaction with Cell Pathways. Additional proxy materials/prospectuses will
be available at these presentations. Representatives from Salomon Smith
Barney, BancBoston Robertson Stephens, and Cell Pathways will be available to
answer any questions. Please call the appropriate person listed above to
reserve space.
As described in the proxy materials previously sent to you, Cell Pathways is a
pharmaceutical company focused on the development and commercialization of
products to prevent and treat cancer. The proposed transaction is intended to
provide substantial funding for the programs of Cell Pathways. In the
transaction, the new Cell Pathways will issue its common stock to the
stockholders of both Tseng Labs and Cell Pathways in exchange for all the stock
they now own in their respective companies, with the exchange ratio as
specified in the Reogranization Agreement. Stockholder meetings to approve the
transaction will be held on November 2 (Cell Pathways) and November 3 (Tseng).
The common stock of the new Cell Pathways is expected to commence trading on
the NASDAQ National Market assuming approval of the transaction at such
stockholders' meetings.
We look forward to your attendance at any of the presentations listed above.
Sincerely, Sincerely,
/s/ Robert J. Towarnicki /s/ John J. Gibbons
- ------------------------ --------------------
Robert J. Towarnicki John J. Gibbons
Chief Executive Officer Chairman of the Board of Directors
Cell Pathways, Inc. Tseng Labs, Inc.
