Exhibit 10.2  DYAX CORP.  1998 Employee Stock Purchase Plan  1.Purpose.  The purpose of this 1998
Employee Stock Purchase Plan (the Plan) is to provide employees of Dyax Corp.
(the Company), and its subsidiaries incorporated under the laws of a jurisdiction
within the United States of America (US Subsidiaries), who wish to become
shareholders of the Company, an opportunity to purchase Common Stock, $0.01 par
value, of the Company (the Common Stock) directly from the Company.  The Plan is intended to qualify as an employee
stock purchase plan within the meaning of Section 423 of the Internal
Revenue Code of 1986, as amended (the Code).  2.Eligible
Employees.  Subject to the provisions of
Sections 7, 8, 9 and 10 below, any individual who is a full-time employee (as
defined below) of the Company or of any of its subsidiaries (as defined in Section 424(f) of
the Code) designated for eligibility to participate in the Plan by the Board of
Directors is eligible to participate in any Offering of Shares (as defined in Section 3
below) made by the Company hereunder.  Board
of Directors means the Companys Board of Directors or any committee to
whom it delegates its authority hereunder, and full-time employee
shall mean any employee whose customary employment is:  (a)20 hours or more per week
and  (b)more than five months in the
calendar year during which the Offering Date (as defined in Section 3
below) occurs (or in the calendar year immediately preceding such calendar year
if there has been no change in the terms of employment that would make the
employee ineligible to participate in the current calendar year).  3.Offering Dates.  From time to time, the
Company, by action of the Board of Directors, will grant rights to purchase
Shares to employees eligible to participate in the Plan pursuant to one or more
offerings (each of which is an Offering on a date or series of dates (each of
which is an Offering Date) designated for this purpose by the Board of
Directors.  4.Prices.  The price per share for each
grant of rights hereunder shall be the lesser of:  (a)eighty-five percent (85%) of
the fair market value of a Share on the Offering Date on which such right was
granted; or  (b)eighty-five percent (85%) of
the fair market value of a Share on the date such right is exercised.


At its discretion, the Board
of Directors may determine a higher price for a grant of rights.  5.Exercise of
Rights and Method of Payment.  (a)Rights granted under the
Plan will be exercisable periodically on specified dates as determined by the
Board of Directors. Unless a participating employee withdraws from the Plan as
provided in Section 11, and subject to the other terms of the Plan, the
employees option for the purchase of Shares will be exercised automatically on
each Purchase Date of an Offering Period, and the maximum number of shares
subject to the option will be purchased at the applicable purchase price with
the accumulated contributions in the employees account.  (b)The method of payment for
Shares purchased upon exercise of rights granted hereunder shall be through
regular payroll deductions or by lump sum cash payment, by delivery of shares
of Common Stock valued at fair market value (as determined by the Board of
Directors) on the date of delivery, or by some combination thereof, as
determined by the Board of Directors.  No
interest shall be paid upon payroll deductions unless specifically provided for
by the Board of Directors.  (c)Any payments received by the
Company from a participating employee and not utilized for the purchase of
Shares upon exercise of a right granted hereunder shall be promptly returned to
such employee by the Company after termination of the right to which the
payment relates.  6.Term of Rights.  The total period from an
Offering Date to the last date on which rights granted on that Offering Date
are exercisable (the Offering Period) shall in no event be longer than twenty-seven
(27) months or such longer period as may then be consistent with Section 423
of the Code.  The Board of Directors when
it authorizes an Offering may designate one or more exercise periods during the
Offering Period when shares will be purchased upon exercise of employees
options (each, an Exercise Period). 
Rights granted on an Offering Date shall be exercisable in full on the
Offering Date or in such proportion on the last day of each exercise period as
the Board of Directors determines.  7.Shares Subject
to the Plan.  (a)The number of shares of
Common Stock that may be sold pursuant to rights granted under the Plan may not
exceed 1,330,000 shares (the Shares); provided, however, that the maximum
number of Shares which shall be available for sale under the Plan during any
Exercise Period shall not exceed the number of Shares equal to 25,000 Shares multiplied
by the number of calendar quarters included in such Exercise Period and, if
necessary, the number of Shares sold during an Exercise Period shall be cut
back in accordance with Section 7(b). 
Appropriate adjustments in the above figures, in the number of Shares
covered by outstanding rights granted hereunder, in the exercise price of the
rights and in the maximum number of Shares which an employee may purchase
(pursuant to this Section 7(a), and Sections 9 and 10 below) shall be made
to give effect to any mergers, consolidations, reorganizations,
recapitalizations, stock splits, stock dividends or other relevant changes in
the capitalization of


the Company occurring after
the effective date of the Plan, provided that no fractional Shares shall be
subject to a right and each right shall be adjusted downward to the nearest
full Share.  In the event of a proposed
dissolution or liquidation of the Company, any Exercise Period and Offering
Period then in progress will terminate immediately prior to the consummation of
such action, unless otherwise provided by the Board.  In the event of a Corporate Transaction (as
defined below), each option outstanding under the Plan shall be assumed or an
equivalent option shall be substituted by the successor corporation or a parent
or subsidiary of such successor corporation. 
In the event that the successor corporation refuses to assume or
substitute for outstanding options, each Exercise Period and Offering Period
then in progress shall be shortened and a new Purchase Date shall be set (the New
Purchase Date), as of which date any Exercise Period and Offering Period then
in progress will terminate.  The New
Purchase Date shall be on or before the date of consummation of the transaction
and the Board shall notify each participating employee in writing, prior to the
New Purchase Date, that the Purchase Date for his or her option has been
changed to the New Purchase Date and that his or her option will be exercised
automatically on the New Purchase Date, unless prior to such date he or she has
withdrawn from the Offering Period as provided in Section 11.  For purposes of this Section 7, Corporate
Transaction means a sale of all or substantially all of the Companys assets,
or a merger, consolidation, or other capital reorganization of the Company with
or into another corporation, or any other transaction or series of related
transactions in which the Companys stockholders immediately prior thereto own
less than 50% of the voting stock of the Company (or its successor or parent)
immediately thereafter.  Either
authorized and unissued Shares or issued Shares heretofore or hereafter
reacquired by the Company may be made subject to rights under the Plan.  If for any reason any right under the Plan
terminates in whole or in part, Shares subject to such terminated right may
again be subjected to a right under the Plan.  (b)Subject to the foregoing, if
the Board of Directors determines that, on a given purchase date for an
Offering (a Purchase Date), the number of Shares with respect to which rights
are to be exercised may exceed (i) the number of Shares of Common Stock
that were available for sale under the Plan on the Offering Date of the
applicable Offering, or (ii) the number of Shares available for sale under
the Plan on such Purchase Date, the Board of Directors may in its sole
discretion provide that the Company shall make a pro rata allocation of the
Shares of Common Stock available for purchase on such Offering Date or Purchase
Date, as applicable, in as uniform a manner as shall be practicable and as it
shall determine in its sole discretion to be equitable among all participant
employees exercising rights to purchase Common Stock on such Purchase Date, and
(x) continue all Offerings then in effect or (y) terminate any or all
Offerings then in effect.  The Company
may make pro rata allocation of the Shares available on the Purchase Date of
any applicable Offering, notwithstanding any authorization of additional Shares
for issuance under the Plan by the Companys stockholders subsequent to the
Offering Date for such Offering.  In the
event of a pro-rata allocation, each participating employees right to purchase
Shares shall be limited to such pro-rata amount of Shares and the remaining
cash balance of the contributions shall be credited to his or her account, and
the participating employees shall not have further rights against the Company
or the Board of Directors.


8.Limitations on
Grants.  (a)No employee shall be granted
a right hereunder if such employee, immediately after the right is granted,
would own stock or rights to purchase 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 subsidiary, computed in accordance with Section 423(b)(3) of
the Code.  (b)No employee shall be granted
a right which permits the employees right to purchase shares under all
employee stock purchase plans of the Company and its subsidiaries to accrue at
a rate which exceeds twenty-five thousand dollars ($25,000) (or such other
maximum as may be prescribed from time to time by the Code) of the fair market
value of such Shares (determined at the time such right is granted) for each
calendar year in which such right is outstanding at any time in accordance with
the provisions of Section 423(b)(8) of the Code.  (c)No right granted to any
participating employee under an Offering, when aggregated with rights granted
under any other Offering still exercisable by the participating employee, shall
cover more shares than may be purchased at an exercise price not to exceed
fifteen percent (15%) of the employees annual rate of compensation on the date
the employee elects to participate in the Offering or such lesser percentage as
the Board of Directors may determine.  9.Limitation on
Number of Shares Purchased.  The maximum number of Shares
that an eligible participating employee may purchase during any Exercise Period
shall not exceed the number of Shares that is equal to 875 Shares multiplied by
the number of calendar quarters included in such Exercise Period, provided that
such purchase shall be further subject to the limitations set forth in Sections
2, 7, and 8.  10.Limit on
Participation.  Participation in an Offering
shall be limited to eligible employees who elect to participate in such
Offering in the manner, and within the time limitations, established by the
Board of Directors when it authorizes the Offering.  11.Withdrawal.  (a)An employee who has elected
to participate in an Offering may cancel such election as to all (but not part)
of the unexercised rights granted under such Offering by giving written notice
of such cancellation to the Company before the date established by the Company
for such purpose.  Upon such withdrawal,
any amounts paid by the employee or withheld from the employees compensation
through payroll deductions for the purpose of purchasing Shares shall be paid
to the employee, without interest, unless otherwise determined by the Board of
Directors.  (b)A participating employees
withdrawal from an Offering will not have any effect upon his or her
eligibility to participate in a succeeding Offering which commences after the
withdrawal or in any similar plan that may hereafter be adopted by the Company.  If a participating employee withdraws from an
Offering, however, payroll deductions shall not


resume at the beginning of
any succeeding Offering unless the employee makes a new election to participate
in the Plan.  12.Tax Withholding.  Each participating employee
shall pay to the Company or the applicable subsidiary, or make provision
satisfactory to the Administrator for payment of, any taxes required by law to
be withheld in respect of the purchase or disposition of Shares no later than
the date of the event creating the tax liability.  In the discretion of the Board of Directors
and subject to applicable law, such tax obligations may be paid in whole or in
part by delivery of Shares to the Company, including Shares purchased under the
Plan, valued at fair market value (as determined by the Board of Directors) on
the date of delivery.  The Company or the
applicable subsidiary may, to the extent permitted by law, deduct any such tax
obligations from any payment of any kind otherwise due to the employee or
withhold Shares purchased hereunder, which shall be valued at fair market value
(as determined by the Board of Directors) on the date of withholding.  13.Termination of
Employment.  Upon the termination of
employment for any reason, including the death of the employee, before the date
on which any rights granted under the Plan are exercisable, all such rights
shall immediately terminate and amounts paid by the employee or withheld from
the employees compensation through payroll deductions for the purpose of
purchasing the Shares shall be paid to the employee or to the employees
estate, without interest unless otherwise determined by the Board of Directors.  14.Participants
Rights as Shareholders and Employees.  (a)No participating employee
shall have any rights as a shareholder in the Shares covered by a right granted
hereunder until such right has been exercised, full payment has been made for
the corresponding Shares and the Share certificate is actually issued.  (b)Each participating employee
is an employee-at-will (that is to say that either the employee or the Company
or any subsidiary may terminate the employment relationship at any time for any
reason or no reason at all) unless and only to the extent provided in a written
employment agreement for a specified term executed by the chief executive
officer of the Company or his duly authorized designee or the authorized
signatory of any subsidiary.  Neither the
adoption, maintenance, nor operation of the Plan nor any grant of rights
hereunder shall confer upon any employee any right with respect to the
continuance of his/her employment with the Company or any subsidiary nor shall
they interfere with the rights of the Company or subsidiary to terminate any
employee at any time or otherwise change the terms of employment, including,
without limitation, the right to promote, demote or otherwise re-assign any
employee from one position to another within the Company or any subsidiary.  15.Rights Not
Transferable.  Rights under the Plan are
not assignable or transferable by a participating employee and are exercisable
only by the employee.


16.Amendments to
or Discontinuation of the Plan.  The Board of Directors of
the Company shall have the right to amend, modify or terminate the Plan at any
time without notice; provided, however, that the then existing rights of all
participating employees shall not be adversely affected thereby, and provided
further that, subject to the provisions of Section 7 above, no such
amendment to the Plan shall, without the approval of the shareholders of the
Company, increase the total number of Shares which may be offered under the
Plan.  17.Effective Date
and Approvals.  (a)This Plan
became effective on January 31, 1998, the date it was adopted by the Board
of Directors, and it was approved by the shareholders of the Company within
twelve (12) months before or after the date of adoption.  (b)The Companys
obligation to offer, sell and deliver the Shares under the Plan is subject to (i) the
approval of any governmental authority required in connection with the
authorization,  issuance or sale of such
Shares, (ii) satisfaction of the listing requirements of any national
securities exchange on which the Shares are then listed and (iii) compliance,
in the opinion of the Companys counsel with, all applicable federal and state
securities and other laws.  18.Term of Plan.  No rights shall be granted
under the Plan after January 30, 2017.  19.Administration
of the Plan.  The Board of Directors or
any committee or person(s) to whom it delegates its authority (the Administrator)
shall administer, interpret and apply all provisions of the Plan as it deems
necessary to meet special circumstances not anticipated or covered expressly by
the Plan.  Nothing contained in this Section shall
be deemed to authorize the Administrator to alter or administer the provisions
of the Plan in a manner inconsistent with the provisions of Section 423 of
the Code.  Determinations made by the
Board of Directors with respect to any provision of the Plan or matter arising in
connection therewith shall be final, conclusive and binding upon the Company
and upon all participants, their heirs or legal representatives.  20.Governing Law.  Subject to overriding
federal law, the Plan shall be governed by and interpreted consistently with
the laws of the State of Delaware.