<PAGE>   1


                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549


                                    FORM 10-Q


(Mark One)

[X] Quarterly report pursuant to Section 13 or 15(d) of the Securities Exchange
Act of 1934 for the quarterly period ended March 31, 1999 or

[ ] Transition report pursuant to Section 13 or 15(d) of the Securities Exchange
Act of 1934 for the transition period from ______________ to ______________.


Commission File Number:    0001066284



                              CELL PATHWAYS, INC.
             (Exact name of registrant as specified in its charter)


         Delaware                                              23-2969600  
         --------                                              ----------  
(State or other jurisdiction of                            (I.R.S. Employer
incorporation or organization)                           Identification Number)


                              702 Electronic Drive
                          Horsham, Pennsylvania 19044
          (Address of principal executive office, including zip code)

                                 (215) 706-3800
              (Registrant's telephone number, including area code)



Indicate by check mark whether the registrant (1) has filed all reports required
to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during
the preceding 12 months (or for such shorter period that the registrant was
required to file such reports), and (2) has been subject to such filing
requirements for the past 90 days.

                  Yes X                                         No
                     ---                                          ---

At April 30, 1999 there were 24,326,263 shares of Common Stock, par value $0.01
per share, outstanding.







<PAGE>   2


                               CELL PATHWAYS, INC.
                          (A DEVELOPMENT STAGE COMPANY)

                               INDEX TO FORM 10-Q
                      FOR THE QUARTER ENDED MARCH 31, 1999


<TABLE>
<CAPTION>
PART 1        FINANCIAL INFORMATION (UNAUDITED)                                         Page
                                                                                        ----
<S>           <C>                                                                       <C>
    Item 1    Financial Statements

              Condensed Consolidated Balance Sheets as of March 31, 1999 and
              December 31, 1998.................................................          3

              Condensed Consolidated Statements of Operations for the three
              months ended March 31, 1999 and 1998 and for the period from
              inception (August 10, 1990) to March 31, 1999.....................          4

              Condensed Consolidated Statements of Cash Flows for the three
              months ended March 31, 1999 and 1998 and for the period from
              inception (August 10, 1990) to March 31, 1999.....................          5

              Notes to Condensed Consolidated Financial Statements .............          6 - 7

    Item 2    Management's Discussion and Analysis of Financial Condition and
              Results of Operations.............................................          8 - 11

    Item 3    Quantitative and Qualitative Disclosures about Market Risk........          11

PART II       OTHER INFORMATION

    Item 1    Legal Proceedings.................................................          12

    Item 6    Exhibits and Reports on Form 8-K..................................          12

              Signatures........................................................          13
</TABLE>




                                       2
<PAGE>   3


                               CELL PATHWAYS, INC.
                          (A DEVELOPMENT STAGE COMPANY)

                      CONDENSED CONSOLIDATED BALANCE SHEETS


<TABLE>
<CAPTION>
                                                                       MARCH 31,     DECEMBER 31,
                                                                         1999            1998
                                                                     ------------    ------------
                              ASSETS                                 (UNAUDITED)
<S>                                                                  <C>             <C>         
CURRENT ASSETS:
  Cash and cash equivalents ......................................   $ 31,477,396    $ 37,232,404
  Prepaid expenses and other .....................................        603,053         512,474
                                                                     ------------    ------------
        Total current assets .....................................     32,080,449      37,744,878

EQUIPMENT and FURNITURE, NET .....................................      1,677,484       1,533,634
OTHER ASSETS .....................................................        954,387         954,187
                                                                     ------------    ------------

                                                                     $ 34,712,320    $ 40,232,699
                                                                     ============    ============
               LIABILITIES AND STOCKHOLDERS' EQUITY

CURRENT LIABILITIES:
  Current installments of obligations under capital lease ........   $    146,260    $    146,260
  Accounts payable ...............................................        406,382         601,988
  Other accrued liabilities ......................................      2,959,037       3,192,436
                                                                     ------------    ------------
        Total current liabilities ................................      3,511,679       3,940,684
                                                                     ------------    ------------

OBLIGATIONS UNDER CAPITAL LEASE, EXCLUDING CURRENT INSTALLMENTS ..        129,697         159,897
                                                                     ------------    ------------

STOCKHOLDERS' EQUITY :
Preferred Stock, $.01 par value, 5,000,000 shares authorized, 
  none issued and outstanding ....................................             --              --
Common Stock $.01 par value, 70,000,000 shares authorized;
  24,315,013 and 24,279,526 shares issued and outstanding ........        243,150         242,796
Additional paid-in capital .......................................     81,499,157      81,256,094
Stock subscription receivable from issuance of Common Stock ......        (37,000)        (37,000)
Deficit accumulated during the development stage .................    (50,634,363)    (45,329,772)
                                                                     ------------    ------------
        Total stockholders' equity ...............................     31,070,944      36,132,118
                                                                     ------------    ------------
                                                                     $ 34,712,320    $ 40,232,699
                                                                     ============    ============
</TABLE>

    The accompanying notes to the condensed consolidated financial statements
                   are an integral part of these statements.



                                       3
<PAGE>   4


                               CELL PATHWAYS, INC.
                          (A DEVELOPMENT STAGE COMPANY)

                 CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS

                                   (UNAUDITED)


<TABLE>
<CAPTION>
                                                 THREE MONTHS ENDED                PERIOD     
                                                      MARCH 31,                FROM INCEPTION 
                                            ----------------------------      (AUGUST 10, 1990)
                                                1999            1998         TO MARCH 31, 1999
                                            ------------    ------------     -----------------
<S>                                         <C>             <C>              <C>         
EXPENSES:                                                                    
   Research and development ............    $  4,527,893    $  3,545,830       $ 41,656,223
   General and administrative ..........       1,144,544       1,315,623          9,953,589
   Provision for redemption of the                                           
     Redeemable Preferred Stock ........              --              --          1,017,000
                                            ------------    ------------       ------------
     Total expenses ....................       5,672,437       4,861,453         52,626,812
INTEREST INCOME ........................         367,846          83,446          1,992,449
                                            ------------    ------------       ------------
NET LOSS ...............................    $ (5,304,591)   $ (4,778,007)      $(50,634,363)
                                            ============    ============       ============
                                                                             
Basic and diluted net loss per Common                                        
Share ..................................    $      (0.22)   $      (1.60)    
                                            ============    ============     
                                                                             
Shares used in computing basic and                                           
   diluted  net loss per Common Share...      24,309,333       2,990,095     
                                            ============    ============     
</TABLE>


    The accompanying notes to the condensed consolidated financial statements
                   are an integral part of these statements.





                                       4
<PAGE>   5


                               CELL PATHWAYS, INC.
                          (A DEVELOPMENT STAGE COMPANY)

                 CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS

                                   (UNAUDITED)

<TABLE>
<CAPTION>
                                                                                                     PERIOD FROM
                                                                                                      INCEPTION  
                                                                          THREE MONTHS ENDED          (AUGUST 10, 
                                                                               MARCH 31,               1990) TO   
                                                                     ----------------------------      MARCH 31,  
                                                                         1999            1998            1999    
                                                                     ------------    ------------    ------------
<S>                                                                  <C>             <C>             <C>          
OPERATING ACTIVITIES:                                                     
   Net loss ......................................................   $ (5,304,591)   $ (4,778,007)   $(50,634,363)

Adjustments to reconcile net loss to net cash used in
operating activities:
   Depreciation expense and amortization .........................        134,368          68,720         522,385
   Issuance of Common Stock for services rendered ................             --              --          48,578
   Issuance of Common Stock options for services rendered ........             --              --          13,313
   Provision for redemption of Redeemable Preferred Stock ........             --              --       1,017,387
   Write-off of deferred offering costs ..........................             --         469,515         469,515
   Other .........................................................             --              --          68,399
   (Increase) decrease in prepaid and other current assets .......        (90,579)          7,308        (284,427)
   Increase in other assets ......................................           (200)             --        (208,448)
   Increase (decrease) in accounts payable and accrued 
     liabilities .................................................       (429,005)       (257,682)        744,428
                                                                     ------------    ------------    ------------
     Net cash flows used in operating activities .................     (5,690,007)     (4,490,146)    (48,243,233)
                                                                     ------------    ------------    ------------
INVESTING ACTIVITIES:
   Purchase of equipment and leasehold improvements ..............       (278,218)     (1,008,343)     (4,678,018)
   Sale of leasehold improvements ................................             --              --       3,000,000
   Cash paid for deposits ........................................             --         (94,383)        (34,767)
                                                                     ------------    ------------    ------------
      Net cash flows used in investing activities ................       (278,218)     (1,102,726)     (1,712,785)
                                                                     ------------    ------------    ------------
FINANCING ACTIVITIES:
  Proceeds from issuance of
   Convertible Preferred Stock, net of related offering costs ....             --              --      47,185,046
  Proceeds from the transaction with Tseng Labs, Inc. ............             --              --      27,966,372
  Proceeds from exercise of Series
   E, F, and G warrants to purchase stock ........................          4,876              --         686,430
  Decrease in shareholder receivable .............................             --              --          23,626
  Cash received for Common Stock options exercised ...............        238,541              --         685,222
  Redemption of Redeemable Preferred Stock .......................             --              --        (546,051)
  Proceeds from bridge loan ......................................             --              --         791,000
  Partner cash contributions .....................................             --              --       5,312,355
  Increase in restricted cash ....................................             --            (581)       (611,172)
  Principal payments under capital lease obligations .............        (30,200)             --         (59,414)
  Proceeds from borrowings .......................................             --              --         150,000
  Repayment of borrowings ........................................             --         (12,924)       (150,000)
                                                                     ------------    ------------    ------------
      Net cash flows provided by (used in) financing activities ..        213,217         (13,505)     81,433,414
                                                                     ------------    ------------    ------------

Net increase (decrease) in cash and cash equivalents .............     (5,755,008)     (5,606,377)     31,477,396

CASH AND CASH EQUIVALENTS,
  beginning of Period ............................................     37,232,404       8,460,839              --
                                                                     ------------    ------------    ------------
CASH AND CASH EQUIVALENTS, end of period .........................   $ 31,477,396    $  2,854,462    $ 31,477,396
                                                                     ============    ============    ============

SUPPLEMENTAL DISCLOSURES OF NONCASH FINANCING ACTIVITIES:
Accrual of leasehold improvements payable ........................   $         --    $         --    $    848,000
                                                                     ============    ============    ============
Accrual of deferred offering costs ...............................   $         --    $    441,375    $    441,375
                                                                     ============    ============    ============
Conversion of partners' investment to Preferred Stock ............   $         --    $         --    $  5,312,355
                                                                     ============    ============    ============
Conversion of bridge loan to Convertible Preferred Stock .........   $         --    $         --    $    791,000
                                                                     ============    ============    ============
Conversion of Convertible Preferred Stock for Common Stock .......   $         --    $         --    $ 53,766,991
                                                                     ============    ============    ============
Issuance of Convertible Preferred Stock to investment advisors ...   $         --    $         --    $    540,742
                                                                     ============    ============    ============
Issuance of Common Stock as payment of management bonus ..........   $         --    $         --    $     59,200
                                                                     ============    ============    ============
Redemption of Redeemable Preferred Stock for Common Stock ........   $         --    $         --    $    545,949
                                                                     ============    ============    ============
Sale of Common Stock in exchange for stock subscription 
  receivable......................................................   $         --    $         --    $     37,000
                                                                     ============    ============    ============
Sale of Convertible Preferred Stock in exchange for stock
  subscription receivable ........................................   $         --    $         --    $     23,626
                                                                     ============    ============    ============
Issuance of Common Stock as payment for accounts payable .........   $         --    $         --    $     48,578
                                                                     ============    ============    ============
</TABLE>


   The accompanying notes to the condensed consolidated financial statements
                   are an integral part of these statements.



                                       5
<PAGE>   6


                               CELL PATHWAYS, INC.
                          (A DEVELOPMENT STAGE COMPANY)

              NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS
                                 MARCH 31, 1999

                                   (UNAUDITED)


1. ORGANIZATION AND BASIS OF PRESENTATION:

Organization

     Cell Pathways, Inc. was incorporated in Delaware in July 1998 as a
subsidiary of, and as of November 3, 1998 successor to, a Delaware corporation
of the same name. As the context requires, "Company" is used herein to signify
the successor and/or the predecessor corporations.

     The Company is a pharmaceutical company focused on the research,
development and future commercialization of products to prevent and treat
cancer. The Company is in the development stage and has not generated any
product revenues to date, nor is there any assurance of any future product
revenues. The Company's intended products are subject to long development cycles
and there is no assurance the Company will be able to successfully develop,
manufacture, obtain regulatory approval for or market its products. During the
period required to develop its products, the Company plans to continue to
finance operations through debt and equity financings, corporate alliances or
through combinations thereof. There is no assurance, however, that such
additional funding will be available on terms acceptable to the Company, if at
all. The Company will continue to be considered in the development stage until
such time as it generates significant revenues from its principal operations. As
of March 31, 1999, the Company had a deficit accumulated during the
developmental stage of $50,634,363.

     On November 3, 1998, the Company completed a financing through the
acquisition of Tseng Labs, Inc. ("Tseng") (a publicly held shell company) in
which the Company issued to Tseng stockholders approximately 5.5 million shares
of the Company's Common Stock and received net proceeds of approximately $26.4
million . The accompanying financial statements include the accounts from
inception (August 10, 1990) through March 31, 1999, (including the accounts of
Tseng after November 3, 1998).

Basis of Presentation

     The unaudited condensed consolidated financial statements as of March 31,
1999 and for the three months ended March 31, 1999 and 1998, are unaudited but
include all adjustments (consisting only of normal recurring adjustments) which,
in the opinion of management, are necessary to state fairly the financial
information set forth therein in accordance with generally accepted accounting
principles. The interim results may not be indicative of the results that may be
expected for the year. These financial statements should be read in conjunction
with the audited consolidated financial statements for the year ended December
31, 1998 included in the Company's annual report on Form 10-K filed with the
Securities and Exchange Commission.






                                       6
<PAGE>   7


2. BASIC AND DILUTED NET LOSS PER COMMON SHARE

     Statement of Financial Accounting Standards No. 128, "Earnings per Share",
became effective at the end of 1997 and requires presentation of two
calculations of earnings per common share. "Basic" earnings per common share
equals net income divided by the weighted average common shares outstanding
during the period. "Diluted" earnings per common share equals net income divided
by the sum of the weighted average common shares outstanding during the period
plus common stock equivalents. The Company's basic and diluted per share amounts
are the same since the assumed exercise of stock options and warrants,
conversion of Convertible Preferred Stock, and the redemption of Redeemable
Preferred Stock are all anti-dilutive. The amount of Common Stock equivalents
excluded from the calculation are options and warrants to purchase 2,108,737 and
711,663 shares of Common Stock, Convertible Preferred Stock convertible into 0
and 10,968,387 shares of Common Stock, warrants to purchase 0 and 194,395 shares
of Convertible Preferred Stock convertible into the same number of shares of
Common Stock and 0 and 33,052 shares of Common Stock to be issued upon
redemption of the Redeemable Preferred Stock that were outstanding as of March
31, 1999 and 1998, respectively.

3. LITIGATION:

     In February and March 1999, five purported stockholder class action
complaints were filed against the Company and certain of its officers and
directors in the United States District Court for the Eastern District of
Pennsylvania alleging that the Company had made false and misleading statements
about the efficacy and near-term commercialization of the Company's lead drug
candidate. The complaints seek unspecified damages on behalf of purported
classes of persons including former Tseng stockholders and persons who purchased
Company Common Stock from November 3 or November 11, 1998 through February 2,
1999, inclusive. The Company believes that the allegations of the complaints are
without merit and intends to vigorously contest the litigations





                                       7
<PAGE>   8


ITEM 2. MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS
OF OPERATIONS

         Cell Pathways, Inc. was incorporated in Delaware in July 1998 as a
subsidiary of, and, as of November 3, 1998, the successor to, a Delaware
corporation of the same name. As the context requires, the "Company" or "CPI" is
used herein to signify the successor and/or the predecessor corporations

         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 and clinical trials, with respect to
both the Company's current product candidates and its future product candidates,
if any; dependence on development of 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, and the timing and scope of any
approval received; acceptance by providers of healthcare reimbursement; the
validity, scope and enforceability of patents; the actions of competitors;
dependence upon third parties; product liability; the need for further
financing; and other risks detailed in Cell Pathways, Inc. 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" and "Risk Factors" in the
Company's report on Form 10-K for the year ended December 31, 1998. Given these
uncertainties, current and prospective investors are cautioned not to place
undue reliance on any such forward-looking statements. The Company undertakes no
obligation to update or revise the statements made herein or the factors which
may relate thereto.

OVERVIEW

         CPI is a development stage pharmaceutical company focused on the
research, development and commercialization of products to prevent and treat
cancer. From the inception of the Company's business in 1990, operating
activities have related primarily to conducting research and development,
raising capital and recruiting personnel. The Company's initial investigational
new drug application ("IND") was filed with the Food and Drug Administration
("FDA") in December 1993 for human clinical trials of the Company's first
product candidate, exisulind. The Company filed an IND for its second product
candidate, CP 461, in December 1998.

         Phase I clinical trials for exisulind to treat adenomatous polyposis
coli ("APC"), an FDA designated orphan drug indication, began in February 1994;
a Phase I/II clinical trial began in August 1995; and a Phase III clinical trial
was initiated in the second quarter of 1997 and concluded in January 1999.
Patients that participated in the Phase III clinical trial have been allowed to
enter an extension trial for exisulind in APC. In December 1997, CPI initiated
Phase II/III clinical trials of exisulind for the treatment of sporadic
adenomatous colonic polyps (patient enrollment completed in April 1999) and for
the prevention of prostate cancer recurrence (patient enrollment completed in
the third quarter of 1998 with the extension phase initiated in February 1999)
as well as a pilot clinical trial of exisulind for the treatment of lung cancer.
In addition, a Phase II/III clinical trial of exisulind for prevention of breast
cancer recurrence (patient enrollment continuing) was initiated in February
1998; a Phase I clinical trial of exisulind in pediatric patients for APC was
initiated in June 1998 and completed in April 1999; a Phase II clinical trial of
exisulind in pediatric patients for APC was initiated in April 1999 (patient
enrollment continuing); and a Phase II clinical trial of exisulind for the
treatment of Barrett's esophagus was initiated in January 1999 (patient
enrollment continuing). A Phase I clinical trial of CP 461 was initiated in the
second quarter of 1999 (patient enrollment continuing).

         On November 3, 1998, CPI completed a financing through the acquisition
of Tseng Labs, Inc. ("Tseng")(a publicly-held company with no continuing
operations which, subsequent to the transaction, became a subsidiary of CPI), in
which CPI issued to Tseng stockholders approximately 5.5 million shares of CPI
Common Stock and received net proceeds of approximately $26.4 million.






                                       8
<PAGE>   9


         In January 1999, CPI completed a pivotal Phase III clinical trial of
exisulind for the indication of familial polyposis coli or APC. Preliminary
evaluation of the unblinded data from this clinical trial suggested that the
trial did not achieve statistical significance. Accordingly, the Company
announced that it anticipated a delay in the filing of a new drug application
("NDA") with the FDA for this indication and that the Company would be
evaluating the data in a process which was expected to continue for some time.
As of April 30, 1999, CPI had not completed its evaluation of the data from the
Phase III clinical trial. Until completion of its analysis, the Company will not
know the extent of delay. There can be no assurance that the Company will file
an NDA for the APC indication, or, if an NDA is filed, that exisulind will
receive marketing approval by the FDA.

         The Company has not received any revenue from the sale of products, and
no product candidate of CPI has been approved for marketing. CPI's income has
been limited to interest income from investments, and CPI's primary source of
capital has been the sale of its equity securities and the transaction with
Tseng. As of March 31, 1999 and December 31, 1998 CPI's accumulated deficit was
$50,634,363 and $45,329,772, respectively, and the unrestricted cash and cash
equivalents for the same periods were $31,477,396 and $37,232,404, respectively.
The Company anticipates that it will continue to incur additional operating
losses for the next several years. There can be no assurance that any of the
Company's product candidates will be approved for marketing, that the Company
will attain profitability or, if profitability is achieved, that the Company
will remain profitable on a quarterly or annual basis in the future. CPI's
operating results will fluctuate from quarter to quarter. Some of these
fluctuations may be significant and, therefore, quarter to quarter comparisons
may not be meaningful.

RESULTS OF OPERATIONS

         Three Months Ended March 31, 1999 Compared with Three Months Ended
March 31, 1998. Total expenses for the three months ended March 31, 1999 were
$5,672,437, an increase of $810,984 or 16.7% from the same period in 1998.
Research and development expenses for the three months ended March 31, 1999 were
$4,527,893, an increase of $982,063 or 27.7%, from the three months ended March
31, 1998. Such increase was primarily due to the procurement of raw materials of
exisulind for on-going and planned clinical trials and in preparation for the
potential commercialization of exisulind, an increase in clinical study related
expenses and additional personnel to support research and product development
activities. General and administrative ("G&A") expenses were $1,144,544 for the
three months ended March 31, 1999, a decrease of $171,079 or 13.0%, from the
same period in 1998. In the three months ended March 31, 1998 the Company
recorded a one-time charge of approximately $715,000 related to expenses for an
initial public offering that was not completed. Partially offsetting the
decrease in G&A expenses resulting from this one-time charge were increases in
personnel and personnel related expenses, facility expenses and marketing
expenses related to commercialization preparations for exisulind.

         Interest income was $367,846 in the three months ended March 31, 1999,
an increase of $284,400 or 340.8% from the same period of 1998 due to higher
average cash balances which resulted from a private equity financing and the
acquisition of Tseng which occurred in the second and fourth quarters of 1998,
respectively.


LIQUIDITY AND CAPITAL RESOURCES

         CPI has financed its operations since inception primarily with the net
proceeds received from private placements of equity securities and the
transaction with Tseng. Financing activities have generated net proceeds of
$81,433,414 from inception through March 31, 1999.

         At March 31, 1999, the Company had cash and cash equivalents of
$31,477,396. The Company's cash position decreased by $5,755,008 for the three
months ended March 31, 1999 primarily due to the net operating loss in the three
months ended March 31, 1999 of $5,304,591 and the addition of $278,218 in
laboratory and computer equipment. CPI invests its excess cash primarily in low
risk, highly liquid money market funds and U.S. government treasuries. CPI had
$611,172 in a restricted account pledged as security for a letter of credit for
a security deposit under the lease of its Horsham, Pennsylvania facility, and as
security to a letter of credit for a portion of a software lease commitment.




                                       9
<PAGE>   10


         CPI leases approximately 40,000 square feet of laboratory and office
space in Horsham, Pennsylvania under a ten - year lease which expires in 2008
and which contains two five - year renewal options. The Company has a lease
expiring in June 1999 on its 7,900 square feet facility in Aurora, Colorado
which was vacated at the end of July 1998. All remaining lease payments
associated with the Aurora facility were recorded in 1998 operations. The
Company believes its facilities will be adequate for the foreseeable future.

         CPI anticipates that quarterly and annual expenditures for preclinical
studies, clinical trials, product development, research, selling, marketing and
administrative expenses will increase significantly in future periods. In
anticipation of possible FDA approval for the marketing of exisulind, in 1998
the Company began to make preparations and incurred expenses for the
commercialization of CPI's first product. Such expenses were expected to be
significant in 1999. As indicated in the Company's February 1999 announcement of
the preliminary evaluation of the data from the APC Phase III clinical trial,
the Company anticipates a delay in the filing of an NDA. Accordingly, the
Company has revised its operating plan and anticipated expenditures. There can
be no assurance that CPI will be able to successfully complete the clinical
development of exisulind for APC or any other indication, that the FDA will
grant approval within the time frame expected, if at all, that the other
developments or expansions in CPI's research, development and commercialization
programs will not require additional funding or encounter delays or that, in
light of these or other circumstances, CPI will be able to achieve anticipated
levels of revenue, expense and cash flow.

         CPI expects that it will require additional financing to continue its
research and development programs. CPI plans to finance its anticipated growth
and development largely through equity or debt financings and/or strategic
alliances with corporate partners. CPI believes, based on its current operating
plans, that its existing cash and cash equivalents balance of approximately
$31.5 million as of March 31, 1999, together with interest earned on the
Company's excess cash balances will provide sufficient working capital to
sustain operations into the fourth quarter of 2000. However, there can be no
assurance the Company will not require additional funding prior to that time, as
the Company must adapt to changing circumstances arising from within the
Company's programs or from outside the Company. There can be no assurance that
additional equity or debt financing or corporate collaborations will be
available on terms acceptable to the Company, if at all. Any additional equity
financing would be dilutive to stockholders. Debt financing, if available, may
include restrictive covenants. Corporate alliances could require the Company to
give up certain marketing rights or other rights to its potential products and
technology. If additional funds should be needed but are not available, the
Company may be required to modify its operations significantly or to obtain
funds by entering into collaborative arrangements or other arrangements on
unfavorable terms. The failure by the Company to raise capital on acceptable
terms if and when needed would have a material adverse effect on the Company's
business, financial condition and results of operations.

INFLATION

         The Company does not believe that inflation has had any significant
impact on its business to date.

INCOME TAXES

         As of March 31, 1999, CPI has net operating loss carryforwards ("NOLs")
for income tax purposes available to offset future federal income tax, subject
to limitations for alternative minimum tax. In addition, the Company has other
significant deferred tax assets that will also offset future income tax. As the
Company has not yet achieved profitable operations, management believes the tax
assets do not satisfy the realization criteria of Statement of Financial
Accounting Standards ("SFAS") No. 109 "Accounting for Income Taxes" and
therefore the Company has recorded a valuation allowance for the entire amount
of its net tax asset as of March 31, 1999. (Also see the Company's annual report
on Form 10-K, note 11 of notes to consolidated financial statements.)


                                       10
<PAGE>   11


         The Tax Reform Act of 1986 contains provisions that may limit the NOLs
available to be used in any given year upon the occurrence of certain events,
including significant changes in ownership interest. A change in ownership of a
company of greater than 50% within a three-year period results in an annual
limitation on CPI's ability to utilize its NOLs from tax periods prior to the
ownership change. The Company believes that the transaction with Tseng triggered
such limitation. However, the Company does not expect such limitation to have a
significant impact on its operations.


RISKS ASSOCIATED WITH THE YEAR 2000


         The Year 2000 issue is the result of computer programs being written
using two digits rather than four to define the applicable year. In other words,
date-sensitive software may recognize a date using "00" as the year 1900 rather
than the year 2000. This could result in system failures or miscalculations
causing disruptions of operations, including, among others, a temporary
inability to process transactions and information, send invoices, or engage in
similar normal business activities.

         The Company does not believe that it has material exposure to the Year
2000 issue with respect to its own information systems. The Company has reviewed
its existing systems and believes that they correctly define the Year 2000.
Non-information technology systems that utilize embedded technology, such as
microcontrollers, HVAC, and security may also face Year 2000 issues. However,
the Company believes that it does not have significant Year 2000 issues related
to non-information technology systems and is currently reviewing these systems.
This review will be completed in 1999.

         In addition, CPI is conducting an analysis to determine the extent to
which its major suppliers', third-party researchers' and clinical trial sites'
systems (insofar as they relate to CPI's business) are subject to the Year 2000
issue. This review will be completed in 1999. CPI is currently unable to predict
the extent to which it would be vulnerable to its third parties failure to
remediate any Year 2000 issues on a timely basis. The failure of a major third
party subject to the Year 2000 issue to convert its systems on a timely basis or
a conversion that is incompatible with CPI's systems could have a material
adverse effect on CPI. However, CPI's activities to date have related primarily
to conducting research and development activities and therefore are not
significantly dependent on external third-party systems. All new contractual
arrangements with third parties require assurance that the third party is Year
2000 compliant.

         To date CPI has not made any contingency plans to address third-party
Year 2000 risks. CPI plans to formulate contingency plans to the extent
necessary in 1999. Historical costs directly related to Year 2000 issue
remediation have been immaterial as CPI's past infrastructure has been built
with Year 2000 issues in mind and to minimize these issues. Based on information
now known to CPI, the Company does not expect to incur material costs in the
future to address the Year 2000 issue, nor does the Company believe that it will
be required to make material capital expenditures to fix Year 2000 issues other
than system upgrades on a normal replacement schedule with only immaterial
opportunity costs of CPI personnel to ensure new systems and third parties are
Year 2000 compliant.


ITEM 3. QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

INTEREST RATE RISK

         The Company's exposure to market risk for changes in interest rates
primarily relates to the Company's investment portfolio. The Company is averse
to principal loss and seeks to limit default risk, market risk and reinvestment
risk. In particular, the Company does not use derivative financial instruments
in its investment portfolio, places its investments with high quality issuers
and, except for investments with the U.S. Government, limits the amount of
credit exposure to any one issuer. The Company mitigates default risk by
investing in only the safest and highest credit quality securities,
predominantly those of the U.S. Government, and by positioning its portfolio to
respond appropriately to a significant reduction in a credit rating of any
investment issuer, guarantor or depository. The portfolio includes only
marketable securities with active secondary or resale markets to ensure
portfolio liquidity and has historically been invested in securities which have
original maturities of less than three months to ensure principal preservation.
As of March 31, 1999, the Company was invested in U.S. Government securities and
money market funds, which were classified as cash equivalents in the Company's
financial statements. The investments had principal (or notional) amounts of
$31,824,446 which were equal to their fair value, an average interest rate of 5%
and mature in less than three months. 



                                       11
<PAGE>   12


Part II. Other Information

Item 1.  Legal Proceedings

     In February and March 1999, five purported stockholder class action
complaints were filed against the Company and certain of its officers and
directors in the United States District Court for the Eastern District of
Pennsylvania alleging that the Company had made false and misleading statements
about the efficacy and near-term commercialization of the Company's lead drug
candidate. The complaints seek unspecified damages on behalf of purported
classes of persons including former Tseng stockholders and persons who purchased
Company Common Stock from November 3 or November 11, 1998 through February 2,
1999, inclusive. The Company believes that the allegations of the complaints are
without merit and intends to vigorously contest the litigations

Item 6.  Exhibits and Reports on Form 8-K

(a)      The following is a list of exhibits filed as part of the Form 10-Q.
            
             3.1  Certificate of Incorporation as amended December 15, 1998 (to
                  reflect typographical corrections).

            27.1  Financial Data Schedule, which is submitted electronically to
                  the Securities and Exchange Commission for information only,
                  and not filed.

(b)      There were no reports on Form 8-K filed during the quarter ended March
         31, 1999.





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<PAGE>   13


                                   SIGNATURES


Pursuant to the requirements of the Securities Exchange Act of 1934, the
Registrant has duly caused this report to be signed on its behalf by the
undersigned, thereunto duly authorized.

                              CELL PATHWAYS,  INC.

Dated:  May 7, 1999           By:  /s/ Robert J. Towarnicki               
                              --------------------------------------------------
                              Robert J. Towarnicki

                              President, Chief Executive Officer and Director
                              (Principal Executive Officer)



Date: May 7, 1999             By:  /s/ Brian J. Hayden                    
                              --------------------------------------------------
                              Brian J. Hayden

                              Chief Financial Officer; Vice President - Finance;
                              Treasurer (Principal Financial and Accounting 
                              Officer)



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