Exhibit 10.28
FORM OF FIRST AMENDMENT TO THE
HUMAN GENOME SCIENCES, INC.
SECOND AMENDED AND RESTATED KEY EXECUTIVE SEVERANCE PLAN
WHEREAS, the Second Amended and Restated Key Executive Severance Plan (the
“Plan”), by its terms, is intended to comply with, or otherwise be exempt from,
Section 409A of the Internal Revenue Code of 1986, as amended (“Section 409A”)
and any regulations and Treasury guidance promulgated thereunder; and
WHEREAS, the Compensation Committee (the “Committee”) of the Board of Directors
of Human Genome Sciences, Inc. (the “Corporation”), upon advice of counsel, has
determined that certain revisions to the Plan are advisable to ensure compliance
with Section 409A.
NOW, THEREFORE, the Plan is amended, effective as of January 1, 2009, as
follows:

1.   Section 3.5(vi) is amended in its entirety to read as follows:

“(vi) “Termination of employment,” “resignation,” or words of similar import, as
used in the Plan means, for purposes of any payments under the Plan that are
payments of deferred compensation subject to Section 409A of the Code, the
Participant’s “separation from service” as defined in Section 409A of the Code.”

2.   Section 3.5(vii) is amended in its entirety to read as follows:

“(vii) If a payment obligation under this Plan arises on account of
Participant’s separation from service while Participant is a “specified
employee” (as defined under Section 409A of the Code and determined in good
faith by the Compensation Committee), any payment of “deferred compensation” (as
defined under Treasury Regulation Section 1.409A-1(b)(1), after giving effect to
the exemptions in Treasury Regulation Sections 1.409A-1(b)(3) through (b)(12))
that is scheduled to be paid within six months after such separation from
service shall accrue at the Prime Rate of interest and shall be made within
15 days after the end of the six-month period beginning on the date of such
separation from service or, if earlier, within 15 days after appointment of the
personal representative or executor of Participant’s estate following
Participant’s death.”
IN WITNESS WHEREOF, the Company has caused this First Amendment to be executed
by its duly authorized officer this ___day of December, 2008.

                  ATTEST:   HUMAN GENOME SCIENCE, INC.    
 
               
By:
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      Its: