EXHIBIT 10.28
 
                              CELL PATHWAYS, INC.
                         EMPLOYEE STOCK PURCHASE PLAN

                           ADOPTED OCTOBER 14, 1997


1.        PURPOSE.

          (A) The purpose of the Employee Stock Purchase Plan (the "Plan") is to
provide a means by which employees of Cell Pathways, Inc., a Delaware
corporation (the "Company"), and its Affiliates, as defined in subparagraph
1(b), which are designated as provided in subparagraph 2(b), may be given an
opportunity to purchase stock of the Company.

          (B) The word "Affiliate" as used in the Plan means any parent
corporation or subsidiary corporation of the Company, as those terms are defined
in Sections 424(e) and (f), respectively, of the Internal Revenue Code of 1986,
as amended (the "Code").

          (C) The Company, by means of the Plan, seeks to retain the services of
its employees, to secure and retain the services of new employees, and to
provide incentives for such persons to exert maximum efforts for the success of
the Company.

          (D) The Company intends that the rights to purchase stock of the
Company granted under the Plan be considered options issued under an "employee
stock purchase plan" as that term is defined in Section 423(b) of the Code.

2.        ADMINISTRATION.

          (A) The Plan shall be administered by the Board of Directors (the
"Board") of the Company unless and until the Board delegates administration to a
Committee, as provided in subparagraph 2(c).  Whether or not the Board has
delegated administration, the Board shall have the final power to determine all
questions of policy and expediency that may arise in the administration of the
Plan.

          (B) The Board shall have the power, subject to, and within the
limitations of, the express provisions of the Plan:

              (I)    To determine when and how rights to purchase stock of the
Company shall be granted and the provisions of each offering of such rights
(which need not be identical).

              (II)   To designate from time to time which Affiliates of the
Company shall be eligible to participate in the Plan.

              (III)  To construe and interpret the Plan and rights granted under
it, and to establish, amend and revoke rules and regulations for its
administration. The Board, in the 

                                       1.

 
exercise of this power, may correct any defect, omission or inconsistency in the
Plan, in a manner and to the extent it shall deem necessary or expedient to make
the Plan fully effective.

              (IV)   To amend the Plan as provided in paragraph 13.

              (V)    Generally, to exercise such powers and to perform such acts
as the Board deems necessary or expedient to promote the best interests of the
Company and its Affiliates and to carry out the intent that the Plan be treated
as an "employee stock purchase plan" within the meaning of Section 423 of the
Code.

          (C) The Board may delegate administration of the Plan to a Committee
composed of not fewer than two (2) members of the Board (the "Committee").  If
administration is delegated to a Committee, the Committee shall have, in
connection with the administration of the Plan, the powers theretofore possessed
by the Board, subject, however, to such resolutions, not inconsistent with the
provisions of the Plan, as may be adopted from time to time by the Board.  The
Board may abolish the Committee at any time and revest in the Board the
administration of the Plan.

3.        SHARES SUBJECT TO THE PLAN.

          (A) Subject to the provisions of paragraph 12 relating to adjustments
upon changes in stock, the stock that may be sold pursuant to rights granted
under the Plan shall not exceed in the aggregate Three Hundred Thousand
(300,000) shares of the Company's common stock after adjustment for the reverse
split of 1 for 1.8157 (the "Common Stock").  If any right granted under the Plan
shall for any reason terminate without having been exercised, the Common Stock
not purchased under such right shall again become available for the Plan.

          (B) The stock subject to the Plan may be unissued shares or reacquired
shares, bought on the market or otherwise.

4.        GRANT OF RIGHTS; OFFERING.

          (A) The Board or the Committee may from time to time grant or provide
for the grant of rights to purchase Common Stock of the Company under the Plan
to eligible employees (an "Offering") on a date or dates (the "Offering
Date(s)") selected by the Board or the Committee.  Each Offering shall be in
such form and shall contain such terms and conditions as the Board or the
Committee shall deem appropriate, which shall comply with the requirements of
Section 423(b)(5) of the Code that all employees granted rights to purchase
stock under the Plan shall have the same rights and privileges.  The terms and
conditions of an Offering shall be incorporated by reference into the Plan and
treated as part of the Plan.  The provisions of separate Offerings need not be
identical, but each Offering shall include (through incorporation of the
provisions of this Plan by reference in the document comprising the Offering or
otherwise) the period during which the Offering shall be effective, which period
shall not exceed twenty-seven (27) months beginning with the Offering Date, and
the substance of the provisions contained in paragraphs 5 through 8, inclusive.

                                       2.

 
          (B) If an employee has more than one right outstanding under the Plan,
unless he or she otherwise indicates in agreements or notices delivered
hereunder:  (1) each agreement or notice delivered by that employee will be
deemed to apply to all of his or her rights under the Plan, and (2) a right with
a lower exercise price (or an earlier-granted right, if two rights have
identical exercise prices), will be exercised to the fullest possible extent
before a right with a higher exercise price (or a later-granted right, if two
rights have identical exercise prices) will be exercised.

5.        ELIGIBILITY.

          (A) Rights may be granted only to employees of the Company or, as the
Board or the Committee may designate as provided in subparagraph 2(b), to
employees of any Affiliate of the Company.  Except as provided in subparagraph
5(b), an employee of the Company or any Affiliate shall not be eligible to be
granted rights under the Plan, unless, on the Offering Date, such employee has
been in the employ of the Company or any Affiliate for such continuous period
preceding such grant as the Board or the Committee may require, but in no event
shall the required period of continuous employment be equal to or greater than
two (2) years.  In addition, unless otherwise determined by the Board or the
Committee and set forth in the terms of the applicable Offering, no employee of
the Company or any Affiliate shall be eligible to be granted rights under the
Plan, unless, on the Offering Date, such employee's customary employment with
the Company or such Affiliate is for at least twenty (20) hours per week and at
least five (5) months per calendar year.

          (B) The Board or the Committee may provide that each person who,
during the course of an Offering, first becomes an eligible employee of the
Company or designated Affiliate will, on a date or dates specified in the
Offering which coincides with the day on which such person becomes an eligible
employee or occurs thereafter, receive a right under that Offering, which right
shall thereafter be deemed to be a part of that Offering.  Such right shall have
the same characteristics as any rights originally granted under that Offering,
as described herein, except that:

              (I)    the date on which such right is granted shall be the
"Offering Date" of such right for all purposes, including determination of the
exercise price of such right;

              (II)   the period of the Offering with respect to such right shall
begin on its Offering Date and end coincident with the end of such Offering; and

              (III)  the Board or the Committee may provide that if such person
first becomes an eligible employee within a specified period of time before the
end of the Offering, he or she will not receive any right under that Offering.

          (C) No employee shall be eligible for the grant of any rights under
the Plan if, immediately after any such rights are granted, such employee owns
stock possessing five percent (5%) or more of the total combined voting power or
value of all classes of stock of the Company or of any Affiliate.  For purposes
of this subparagraph 5(c), the rules of Section 424(d) of the Code shall apply
in determining the stock ownership of any employee, and stock which such

                                       3.

 
employee may purchase under all outstanding rights and options shall be treated
as stock owned by such employee.

          (D) An eligible employee may be granted rights under the Plan only if
such rights, together with any other rights granted under "employee stock
purchase plans" of the Company and any Affiliates, as specified by Section
423(b)(8) of the Code, do not permit such employee's rights to purchase stock of
the Company or any Affiliate to accrue at a rate which exceeds twenty-five
thousand dollars ($25,000) of fair market value of such stock (determined at the
time such rights are granted) for each calendar year in which such rights are
outstanding at any time.

          (E) Officers of the Company and any designated Affiliate shall be
eligible to participate in Offerings under the Plan, provided, however, that the
Board may provide in an Offering that certain employees who are highly
compensated employees within the meaning of Section 423(b)(4)(D) of the Code
shall not be eligible to participate.

6.        RIGHTS; PURCHASE PRICE.

          (A) On each Offering Date, each eligible employee, pursuant to an
Offering made under the Plan, shall be granted the right to purchase up to the
number of shares of Common Stock of the Company purchasable with a percentage
designated by the Board or the Committee not exceeding fifteen percent (15%) of
such employee's Earnings (as defined in subparagraph 7(a)) during the period
which begins on the Offering Date (or such later date as the Board or the
Committee determines for a particular Offering) and ends on the date stated in
the Offering, which date shall be no later than the end of the Offering.  The
Board or the Committee shall establish one or more dates during an Offering (the
"Purchase Date(s)") on which rights granted under the Plan shall be exercised
and purchases of Common Stock carried out in accordance with such Offering.

          (B) In connection with each Offering made under the Plan, the Board or
the Committee may specify a maximum number of shares that may be purchased by
any employee as well as a maximum aggregate number of shares that may be
purchased by all eligible employees pursuant to such Offering.  In addition, in
connection with each Offering that contains more than one Purchase Date, the
Board or the Committee may specify a maximum aggregate number of shares which
may be purchased by all eligible employees on any given Purchase Date under the
Offering.  If the aggregate purchase of shares upon exercise of rights granted
under the Offering would exceed any such maximum aggregate number, the Board or
the Committee shall make a pro rata allocation of the shares available in as
nearly a uniform manner as shall be practicable and as it shall deem to be
equitable.

          (C) The purchase price of stock acquired pursuant to rights granted
under the Plan shall be not less than the lesser of:

              (I)    an amount equal to eighty-five percent (85%) of the fair
market value of the stock on the Offering Date; or

                                       4.

 
              (II)   an amount equal to eighty-five percent (85%) of the fair
market value of the stock on the Purchase Date.

          (D) For purposes of the Plan, "fair market value" means, as of any
date, the value of the common stock of the Company determined as follows:

              (I)    If the common stock is listed on any established stock
exchange or traded on the Nasdaq National Market or the Nasdaq SmallCap Market,
the fair market value of a share of common stock shall be the closing sales
price for such stock (or the closing bid, if no sales were reported) as quoted
on such exchange or market (or the exchange or market with the greatest volume
of trading in the Company's common stock) on the day of determination, as
reported in The Wall Street Journal or such other source as the Board deems
reliable.

              (II)   In the absence of such markets for the common stock, the
fair market value shall be determined in good faith by the Board.

7.        PARTICIPATION; WITHDRAWAL; TERMINATION.

          (A) An eligible employee may become a participant in the Plan pursuant
to an Offering by delivering a participation agreement to the Company within the
time specified in the Offering, in such form as the Company provides.  Each such
agreement shall authorize payroll deductions of up to the maximum percentage
specified by the Board or the Committee of such employee's Earnings during the
Offering.  "Earnings" is defined as an employee's regular salary or wages
(including amounts thereof elected to be deferred by the employee, that would
otherwise have been paid, under any arrangement established by the Company
intended to comply with Section 401(k), Section 402(e)(3), Section 125, Section
402(h), or Section 403(b) of the Code, and also including any deferrals under a
non-qualified deferred compensation plan or arrangement established by the
Company), which shall include or exclude (as provided for each Offering) the
following items of compensation: bonuses, commissions, overtime pay, incentive
pay, profit sharing, other remuneration paid directly to the employee, the cost
of employee benefits paid for by the Company or an Affiliate, education or
tuition reimbursements, imputed income arising under any group insurance or
benefit program, traveling expenses, business and moving expense reimbursements,
income received in connection with stock options, contributions made by the
Company or an Affiliate under any employee benefit plan, and similar items of
compensation, as determined by the Board or Committee.    The payroll deductions
made for each participant shall be credited to an account for such participant
under the Plan and shall be deposited with the general funds of the Company.  A
participant may reduce (including to zero) or increase such payroll deductions,
and an eligible employee may begin such payroll deductions, after the beginning
of any Offering only as provided for in the Offering.  A participant may make
additional payments into his or her account only if specifically provided for in
the Offering and only if the participant has not had the maximum amount withheld
during the Offering.

          (B) At any time during an Offering, a participant may terminate his or
her payroll deductions under the Plan and withdraw from the Offering by
delivering to the Company a notice of withdrawal in such form as the Company
provides.  Such withdrawal may be elected at any 

                                       5.

 
time prior to the end of the Offering except as provided by the Board or the
Committee in the Offering. Upon such withdrawal from the Offering by a
participant, the Company shall distribute to such participant all of his or her
accumulated payroll deductions (reduced to the extent, if any, such deductions
have been used to acquire stock for the participant) under the Offering, without
interest, and such participant's interest in that Offering shall be
automatically terminated. A participant's withdrawal from an Offering will have
no effect upon such participant's eligibility to participate in any other
Offerings under the Plan but such participant will be required to deliver a new
participation agreement in order to participate in subsequent Offerings under
the Plan.

          (C) Rights granted pursuant to any Offering under the Plan shall
terminate immediately upon cessation of any participating employee's employment
with the Company and any designated Affiliate, for any reason, and the Company
shall distribute to such terminated employee all of his or her accumulated
payroll deductions (reduced to the extent, if any, such deductions have been
used to acquire stock for the terminated employee), under the Offering, without
interest.

          (D) Rights granted under the Plan shall not be transferable by a
participant otherwise than by will or the laws of descent and distribution, or
by a beneficiary designation as provided in paragraph 14 and, otherwise during
his or her lifetime, shall be exercisable only by the person to whom such rights
are granted.

8.        EXERCISE.

          (A) On each Purchase Date specified therefor in the relevant Offering,
each participant's accumulated payroll deductions and other additional payments
specifically provided for in the Offering (without any increase for interest)
will be applied to the purchase of whole shares of stock of the Company, up to
the maximum number of shares permitted pursuant to the terms of the Plan and the
applicable Offering, at the purchase price specified in the Offering.  No
fractional shares shall be issued upon the exercise of rights granted under the
Plan.  The amount, if any, of accumulated payroll deductions remaining in each
participant's account after the purchase of shares which is less than the amount
required to purchase one share of stock on the final Purchase Date of an
Offering shall be held in each such participant's account for the purchase of
shares under the next Offering under the Plan, unless such participant withdraws
from such next Offering, as provided in subparagraph 7(b), or is no longer
eligible to be granted rights under the Plan, as provided in paragraph 5, in
which case such amount shall be distributed to the participant after such final
Purchase Date, without interest.  The amount, if any, of accumulated payroll
deductions remaining in any participant's account after the purchase of shares
which is equal to the amount required to purchase whole shares of stock on the
final Purchase Date of an Offering shall be distributed in full to the
participant after such Purchase Date, without interest.

          (B) No rights granted under the Plan may be exercised to any extent
unless the shares to be issued upon such exercise under the Plan (including
rights granted thereunder) are covered by an effective registration statement
pursuant to the Securities Act of 1933, as amended (the 

                                       6.

 
"Securities Act") and the Plan is in material compliance with all applicable
state, foreign and other securities and other laws applicable to the Plan. If on
a Purchase Date in any Offering hereunder the Plan is not so registered or in
such compliance, no rights granted under the Plan or any Offering shall be
exercised on such Purchase Date, and the Purchase Date shall be delayed until
the Plan is subject to such an effective registration statement and such
compliance, except that the Purchase Date shall not be delayed more than twelve
(12) months and the Purchase Date shall in no event be more than twenty-seven
(27) months from the Offering Date. If on the Purchase Date of any Offering
hereunder, as delayed to the maximum extent permissible, the Plan is not
registered and in such compliance, no rights granted under the Plan or any
Offering shall be exercised and all payroll deductions accumulated during the
Offering (reduced to the extent, if any, such deductions have been used to
acquire stock) shall be distributed to the participants, without interest.

9.        COVENANTS OF THE COMPANY.

          (A) During the terms of the rights granted under the Plan, the Company
shall keep available at all times the number of shares of stock required to
satisfy such rights.

          (B) The Company shall seek to obtain from each federal, state, foreign
or other regulatory commission or agency having jurisdiction over the Plan such
authority as may be required to issue and sell shares of stock upon exercise of
the rights granted under the Plan.  If, after reasonable efforts, the Company is
unable to obtain from any such regulatory commission or agency the authority
which counsel for the Company deems necessary for the lawful issuance and sale
of stock under the Plan, the Company shall be relieved from any liability for
failure to issue and sell stock upon exercise of such rights unless and until
such authority is obtained.

          (C) The Company shall have the authority to withhold applicable income
or employment taxes from the compensation paid to a participant to the extent
that the Company determines in its discretion that such withholding is required
by law, whether at the time of (i) the grant of a right under the Plan, (ii) the
time that a participant purchases stock under the plan, or (iii) otherwise.

10.       USE OF PROCEEDS FROM STOCK.

          Proceeds from the sale of stock pursuant to rights granted under the
Plan shall constitute general funds of the Company.

11.       RIGHTS AS A STOCKHOLDER.

          A participant shall not be deemed to be the holder of, or to have any
of the rights of a holder with respect to, any shares subject to rights granted
under the Plan unless and until the participant's shareholdings acquired upon
exercise of rights hereunder are recorded in the books of the Company.

                                       7.

 
12.       ADJUSTMENTS UPON CHANGES IN STOCK.

          (A) If any change is made in the stock subject to the Plan, or subject
to any rights granted under the Plan (through merger, consolidation,
reorganization, recapitalization, stock dividend, dividend in property other
than cash, stock split, liquidating dividend, combination of shares, exchange of
shares, change in corporate structure or other transaction not involving the
receipt of consideration by the Company), the Plan and outstanding rights will
be appropriately adjusted in the class(es) and maximum number of shares subject
to the Plan and the class(es) and number of shares and price per share of stock
subject to outstanding rights.  Such adjustments shall be made by the Board or
the Committee, the determination of which shall be final, binding and
conclusive.  (The conversion of any convertible securities of the Company shall
not be treated as a "transaction not involving the receipt of consideration by
the Company.")

          (B) In the event of:  (1) a dissolution or liquidation of the Company;
(2) a merger or consolidation in which the Company is not the surviving
corporation; (3) a reverse merger in which the Company is the surviving
corporation but the shares of the Company's Common Stock outstanding immediately
preceding the merger are converted by virtue of the merger into other property,
whether in the form of securities, cash or otherwise; or (4) the acquisition by
any person, entity or group within the meaning of Section 13(d) or 14(d) of the
Securities Exchange Act of 1934, as amended (the "Exchange Act") or any
comparable successor provisions (excluding any employee benefit plan, or related
trust, sponsored or maintained by the Company or any Affiliate of the Company)
of the beneficial ownership (within the meaning of Rule 13d-3 promulgated under
the Exchange Act, or comparable successor rule) of securities of the Company
representing at least fifty percent (50%) of the combined voting power entitled
to vote in the election of directors, then, as determined by the Board in its
sole discretion, (i) any surviving or acquiring corporation may assume
outstanding rights or substitute similar rights for those under the Plan, (ii)
such rights may continue in full force and effect, or (iii) participants'
accumulated payroll deductions may be used to purchase Common Stock immediately
prior to the transaction described above and the participants' rights under the
ongoing Offering terminated.

13.       AMENDMENT OF THE PLAN.

          (A) The Board at any time, and from time to time, may amend the Plan.
However, except as provided in paragraph 12 relating to adjustments upon changes
in stock, no amendment shall be effective unless approved by the stockholders of
the Company within twelve (12) months before or after the adoption of the
amendment, where the amendment will:

              (I)    Increase the number of shares reserved for rights under the
Plan;

              (II)   Modify the provisions as to eligibility for participation
in the Plan, but only to the extent such modification requires stockholder
approval in order for the Plan to obtain employee stock purchase plan treatment
under Section 423 of the Code or to comply with the requirements of Rule 16b-3
promulgated under the Securities Exchange Act of 1934, as amended ("Rule 16b-
3"); or

                                       8.

 
              (III)  Modify the Plan in any other way if such modification
requires stockholder approval in order for the Plan to obtain employee stock
purchase plan treatment under Section 423 of the Code or to comply with the
requirements of Rule 16b-3.

It is expressly contemplated that the Board may amend the Plan in any respect
the Board deems necessary or advisable to provide eligible employees with the
maximum benefits provided or to be provided under the provisions of the Code and
the regulations promulgated thereunder relating to employee stock purchase plans
and/or to bring the Plan and/or rights granted under it into compliance
therewith.

          (B) Rights and obligations under any rights granted before amendment
of the Plan shall not be impaired by any amendment of the Plan, except with the
consent of the person to whom such rights were granted, or except as necessary
to comply with any laws or governmental regulations, or except as necessary to
ensure that the Plan and/or rights granted under the Plan comply with the
requirements of Section 423 of the Code.

14.       DESIGNATION OF BENEFICIARY.

          (A) A participant may file a written designation of a beneficiary who
is to receive any shares and cash, if any, from the participant's account under
the Plan in the event of such participant's death subsequent to the end of an
Offering but prior to delivery to the participant of such shares and cash.  In
addition, a participant may file a written designation of a beneficiary who is
to receive any cash from the participant's account under the Plan in the event
of such participant's death during an Offering.

          (B) Such designation of beneficiary may be changed by the participant
at any time by written notice.  In the event of the death of a participant and
in the absence of a beneficiary validly designated under the Plan who is living
at the time of such participant's death, the Company shall deliver such shares
and/or cash to the executor or administrator of the estate of the participant,
or if no such executor or administrator has been appointed (to the knowledge of
the Company), the Company, in its sole discretion, may deliver such shares
and/or cash to the spouse or to any one or more dependents or relatives of the
participant, or if no spouse, dependent or relative is known to the Company,
then to such other person as the Company may designate.

15.       TERMINATION OR SUSPENSION OF THE PLAN.

          (A) The Board in its discretion, may suspend or terminate the Plan at
any time.  No rights may be granted under the Plan while the Plan is suspended
or after it is terminated.

          (B) Rights and obligations under any rights granted while the Plan is
in effect shall not be impaired by suspension or termination of the Plan, except
as expressly provided in the Plan or with the consent of the person to whom such
rights were granted, or except as necessary to comply with any laws or
governmental regulation, or except as necessary to ensure that the Plan and/or
rights granted under the Plan comply with the requirements of Section 423 of the
Code.

                                       9.

 
16.       EFFECTIVE DATE OF PLAN.

          The Plan shall become effective on the same day that the Company's
initial public offering of shares of common stock becomes effective (the
"Effective Date"), but no rights granted under the Plan shall be exercised
unless and until the Plan has been approved by the stockholders of the Company
within twelve (12) months before or after the date the Plan is adopted by the
Board or the Committee, which date may be prior to the Effective Date.

                                      10.