Exhibit 10.7  Dyax Corp.
  300 Technology Square
  Cambridge, MA 02139  CONFIDENTIAL
DOCUMENT  March 2, 2009  Henry
E. Blair
c/o Dyax Corp. 300
Technology Square Cambridge,
MA 02139  Dear
Henry,  On
behalf of Dyax Corp., this letter will confirm the terms of your continued
employment as an employee of Dyax now that you have retired as its Chief
Executive Officer and are continuing to serve as its Chairman of the Board.  Supervision:  You
will be reporting directly to the Companys Chief Executive Officer with
respect to your duties other than as Chairman of the Board.  Responsibilities:  As
Chairman of the Board of Directors, you will be responsible for managing the
meetings of the Board of Directors.    In
your role as an employee of the Company you will be responsible for (i) facilitating
the transition of the role of Chief Executive Officer by acting in an advisory
role to the current Chief Executive Officer, and (ii) such other  duties as the Companys Chief Executive
Officer may designate consistent with your role as Chairman and former Chief
Executive Officer.  All such duties will
be performed and discharged, faithfully, diligently and to the best of your
ability and in compliance with all applicable laws and regulations.  Salary:  As
an exempt employee you will receive a monthly salary of $54,167 on a full-time
basis during 2009, or at such reduced commitment and pro-rated compensation as
the Chief Executive Officer may approve, and thereafter as a part-time employee
for up to twenty (20) hours per week or such reduced commitment as the Chief
Executive Officer may approve, which in any case shall result in a pro-rated
reduction of your monthly salary equal to the amount of your approved work
commitment.   Your monthly salary will be
paid in accordance with the Companys standard payroll practice.  Given the advisory nature of your role, you
will not be eligible to participate in the Companys bonus plan.  Benefits:  You
will eligible to participate in Dyaxs employee benefits in the same manner
provided generally to Dyaxs exempt employees, including health and dental
insurance, 401(k) savings plan, short-term disability insurance and life
insurance.  In addition, upon your
retirement or other termination of employment other than by Dyax for cause, you
will be entitled to receive a Medicare supplement at a fixed dollar cost to
Dyax of $6,000 annually for ten years after termination of employment, provided
that the initial payment shall be delayed until expiration of the Delay Period
described in Code Section 409A below.


Acceleration
and Extension of Options:  Upon
your execution and delivery of this agreement to Dyax, all option shares  subject to stock options held by you as of January 2,
2009 that were not then exercisable (the Unvested Shares) shall become
immediately exercisable effective as of the date of such execution and delivery
of this agreement, and the period of exercisability of all outstanding options
held by you as of January 2, 2009 (the Pre-Existing Options) shall be
extended to permit exercise of each such option for its stated term until the
tenth anniversary of its respective date of grant; provided, however, that if
your employment is terminated for cause your rights to exercise your stock
options shall be forfeited as set forth below. 
In addition,if you die while holding any of your Pre-Existing
Options, then the personal representative of your estate or the person or
persons to whom any such option is transferred pursuant to your will or the
laws of inheritance shall have the full stated term of the
Pre-Existing Option to exercise such option; provided, however, that
notwithstanding the extension of the exercise period of your Pre-Existing
Options, you acknowledge and agree, on behalf of your estate and your heirs,
that if any of such options that was awarded to you as an incentive stock
option (an ISO) is not exercised within one year after your date of death
then it shall cease to qualify as an incentive stock option under the Code
and shall thereafter be treated as a non-statutory stock option.  You also acknowledge and agree that to the
extent that any of your Pre-Existing Options is an ISO and has an exercise
price below the closing price of Dyax common stock on the date of this agreement,
the amendments effected by this agreement shall disqualify it from continuing
to be an ISO and it shall hereafter be treated as a non-statutory stock option.  Termination and Severance:  All
employees at Dyax are employed at will.  Employment
at will refers to the traditional relationship between employer and employee,
allowing either party to unilaterally terminate the employment
relationship.  While we ask you to
provide at least ninety (90) days prior notice, you will be free to resign at
any time.  Similarly, the Company
reserves the right to terminate your employment at any time, with or without
cause and with or without prior notice. 
Additionally, this agreement
shall terminate on December 31, 2011, unless you and Dyax mutually agree
to extend it.  However,
upon the first to occur of termination 
of your employment by the Company without cause or a change in
control of the Company (as defined in the regulations promulgated pursuant to Section 409A
of the Internal Revenue Code of 1986, as amended (the Code)), Dyax agrees to
pay you a lump sum severance payment in an amount equal to twelve (12) times
your monthly base salary in effect at the date of termination (giving effect to
any pro rating of that salary), less any applicable withholding.  Other than your rights under COBRA, your
Medicare supplement and any continued vesting of any options granted to you
after January 2, 2009 for your service as Chairman of the Board, all other
benefits to you will cease upon any termination of your employment.  If
your employment is terminated for cause by the Company or is terminated by
you for any reason, your compensation and 
benefits will cease as of the termination date.  In addition, solely in the event your
employment is terminated for cause by the Company, your Accelerated Stock
Options will be immediately forfeited and terminated to the extent they have
not been exercised before the date of your termination and your right to
exercise all your Pre-Existing Options beyond 90 days after such termination of
employment shall also be forfeited and of no further effect.  For purposes of this offer, cause will
mean:  (i)the willful and continued failure by you to
perform your duties with the Company (other than any such failure resulting
from your incapacity due to physical or mental illness), as determined by the
Board of Directors; or (ii)any act of material misconduct or the
commission of any act of dishonesty or moral turpitude in connection with your
employment, as determined by the Board of Directors; or (iii)the conviction of a felony or a crime
involving moral turpitude.  Code Section 409A:  A
termination of employment shall not be deemed to have occurred for purposes of
any provision of this Agreement providing for the payment of any amounts or
benefits that is considered deferred compensation upon or following a
termination of employment unless such termination of employment is also a separation
from  2


service
within the meaning of Code Section 409A. 
If you are a specified employee on the date of termination within the
meaning of that term under Code Section 409A(a)(2)(B), then with regard to
any payment or the provision of any benefit that is considered deferred
compensation under Code Section 409A payable on account of a separation
from service, such payment or benefit shall be made or provided at the date
which is the earlier of (i) the expiration of the six (6)-month period
measured from the date of your separation from service, and (ii) the
date of your death (the Delay Period). 
Upon the expiration of the Delay Period, all payments and benefits
delayed pursuant to this provision shall be paid or reimbursed to you in a lump
sum.  All
expenses or other reimbursements under this Agreement shall be made on or prior
to the last day of the taxable year following the taxable year in which such
expenses were incurred by you (provided that if any such reimbursements
constitute taxable income to you, such reimbursements shall be paid no later
than March 15th of the calendar year following the calendar year in which
the expenses to be reimbursed were incurred), and no such reimbursement or
expenses eligible for reimbursement in any taxable year shall in any way affect
the expenses eligible for reimbursement in any other taxable year.  If
this letter correctly sets forth our agreement on the subject matter hereof,
kindly sign and return to Dyax the enclosed copy of this letter.  Such document, together with your
confidentiality agreement in favor of the Company, will then constitute the
complete agreement with respect to your employment by the Company, and will
supersede all prior oral or written agreements relating to such matters,
including, without limitation, any previous employment agreements you had with
Dyax.   Sincerely,/s/
  Gustav ChristensenGustav
  ChristensenPresident
  and Chief Executive Officer  I
acknowledge receipt and agree with the foregoing terms and conditions.   /s/
  Henry E. BlairHenry
  E. Blair  3