EXHIBIT 10.10

December 27, 1999


Dr. Charles E. Bugg
Chairman and CEO
BioCryst Pharmaceuticals, Inc.
2190 Parkway Lake Drive
Birmingham, Alabama 35244

Dear Dr. Bugg:

      This letter agreement (the "Agreement") will serve to confirm our
agreement with respect to the terms and conditions of the employment of Dr.
Charles E. Bugg (the "Employee") by BioCryst Pharmaceuticals, Inc., a Delaware
corporation ("BioCryst"), after December 31, 1999.

      The terms and conditions of such employment are as follows:

1. Term of Employment. Subject to the terms and conditions of this Agreement,
BioCryst hereby employs Employee, effective January 1, 2000, as Chairman of the
Board and Chief Executive Officer of BioCryst, and Employee hereby accepts such
employment. In addition, during the terms of this Agreement, BioCryst shall use
its best efforts to provide that the Employee shall be elected as a member of
the Board of Directors of BioCryst each year. BioCryst acknowledges and agrees
that after December 31, 1999 Employee may also hold positions at the University
of Alabama at Birmingham as Professor Emeritus of Biochemistry, Adjunct Senior
Scientist in the Comprehensive Cancer Center, Adjunct Senior Scientist in the
Center for Macromolecular Crystallography, and such other appointments that
might be offered to the Employee from time to time, and the Employee will be
permitted to devote up to ten percent (10%) of his time to such activities and
to research and other activities at the University of Alabama at Birmingham, if
the Employee desires to participate in such activities. Otherwise, after
December 31, 1999 the Employee shall devote his full business time and energies
to BioCryst. Except as provided in this paragraph 1, the Employee shall not,
during the term of his employment, engage in any other business activity that
would interfere with, or prevent him from carrying out, his duties and
responsibilities under this Agreement. BioCryst hereby agrees and acknowledges
that any compensation which the Employee receives from participation in such
allowable activities shall be outside the scope of this Agreement and in
addition to any compensation received hereunder. The term of employment of
Employee under this Agreement shall commence as of January 1, 2000 and shall
terminate on December 31, 2002, unless earlier terminated in accordance with the
provisions of paragraph 3 hereof.

2. Basic Full-Time Compensation and Benefits.

            (a) As basic yearly compensation for services rendered under this
      Agreement for services rendered under paragraph 1 of this Agreement,
      Employee shall be entitled to receive from BioCryst, for the term of his
      full-time employment under this Agreement, an aggregate salary of $355,465
      per year which remuneration shall be payable in equal monthly installments
      of $29,602.08 on the first business day of each month during the term of
      this Agreement, beginning on January 1, 2000. This salary will be reviewed
      annually by the Board of Directors and may be raised at the discretion of
      the Board.

            (b) In addition to the basic compensation set forth in (a) above,
      Employee shall be entitled to receive such other benefits and perquisites
      provided to other executive officers of BioCryst which benefits may
      include, without limitation, reasonable vacation, sick leave, medical
      benefits, life insurance, and participation in profit sharing or
      retirement plans.


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            (c) In addition to the compensation set forth in paragraphs 2(a) and
      (b) above, the Board of Directors of BioCryst may from time to time, in
      its discretion, also grant such other cash or stock bonuses to the
      Employee either as an award or as an incentive as it shall deem desirable
      or appropriate.

3. Stock Options.

            (a) BioCryst hereby agrees that it will grant a stock option to the
      Employee on or before December 31 of each year during the term of this
      Agreement, beginning with the year 2000, to purchase at least 25,000
      shares of Common Stock of BioCryst, par value $0.01 per share (the "Common
      Stock"), from the authorized and unissued stock or treasury stock of
      BioCryst, based on the performance of the Employee. The Board of Directors
      of BioCryst shall determine, in its sole discretion, based upon the
      performance of the Employee and the results of operations of BioCryst for
      the immediately preceding twelve (12) months, the number of shares which
      may be purchased pursuant to each such option, provided the number of
      shares shall not in any case be less than 25,000. In addition, BioCryst
      shall also grant to the Employee an option to purchase 100,000 shares of
      BioCryst Common Stock upon the occurrence of each of the following:

                        (i)   submission by BioCryst to the United States Food
                              and Drug Administration (the "FDA") of any new
                              drug application;

                        (ii)  submission by any licensee of BioCryst to the FDA
                              of any new drug application utilizing a product or
                              process licensed by the licensee from BioCryst;

                        (iii) final approval of each such new drug application
                              of either BioCryst or such licensee by the FDA.

      The exercise price per share for each share of BioCryst Common Stock
      subject to each such option shall be the fair market value thereof on the
      date such option is granted.

            (b) The parties intend for the options granted pursuant to this
      Agreement (the "Options") to qualify as "incentive stock options," as that
      term is defined in Section 422 of the Internal Revenue Code of 1986, as
      amended ("Section 422"). The parties understand that the portion of any
      Option, together with the portion of any other incentive stock option
      granted by BioCryst and its parent and subsidiary corporations, if any,
      which may become exercisable in any year in excess of an aggregate of
      $100,000 fair market value, determined as of the date such Option or other
      option, as the case may be, was granted, may not be treated as an
      incentive stock option under Section 422. The Options may be exercised and
      the Common Stock may be purchased by the Employee as a result of such
      exercise only within the periods and to the extent hereinafter set forth.

            (c) Each Option shall be 25% exercisable one year after the date it
      was granted, and the remaining seventy-five percent (75%) shall vest and
      become exercisable at the rate of 1/48th per month, commencing with the
      thirteenth (13th) month after the date such Option was granted, and
      continuing to vest for the succeeding months until fully vested and
      exercisable. Notwithstanding the foregoing, in the event of a Change in
      Control or Structure, as defined below, or as set forth in subparagraphs
      (d) or (e) below, the entire amount of each Option shall become
      immediately exercisable.

            (d) If the Employee suffers a period of permanent disability, as
      defined in paragraph 4(b) below, the entire amount of each Option may be
      exercised at any time after termination for such disability and before the
      earlier of twenty-four (24) months or the expiration date of the Option.

            (e) In the event of the death of the Employee, the executor or
      administrator of the estate of the Employee, or other reliable transferee,
      shall have the right to exercise each Option, in its entirety, within the
      earlier of twenty-four (24) months after the Employee's death or before
      the original expiration of the Option. Except as provided in this
      subparagraph (e), the Employee shall not have the right to transfer any
      Option.


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            (f) Subject to paragraphs 3(c), (d), and (e) above, each Option may,
      in the Employee's sole discretion, be exercised in full at one time as to
      the total number of shares of Common Stock then exercisable, or in part
      from time to time as to a specific number of shares of Common Stock then
      exercisable. A partial exercise of an Option will not affect the
      exercisability of the remainder of the Option.

            (g) In no event shall the period for exercising an Option exceed ten
      (10) years from the date such Option is granted.

            (h) For purposes of this Agreement, the term "Change of Control or
      Structure" shall mean:

                  (i)   The acquisition by any person, entity or "group," within
                        the meaning of Section 13(d)(3) or 14(d)(2) of the
                        Securities Exchange Act of 1934 (the "Exchange Act") of
                        beneficial ownership (within the meaning of Rule 13d-3
                        promulgated under the Exchange Act) of more than fifty
                        percent (50%) of the then outstanding shares of Common
                        Stock at the time of such event or the combined voting
                        power of BioCryst's then outstanding voting securities
                        generally entitled to vote in the election of directors,
                        or

                  (ii)  any merger, consolidation or business combination of
                        BioCryst with or into any other entity, or

                  (iii) any transaction effected by a sale of substantially all
                        the assets of BioCryst.

            (i) In the event the employment of the Employee is terminated for
      any reason other than as set forth in subparagraph (d) or (e) above, the
      Employee may, within three (3) months following the date of such
      termination, exercise each Option to the full extent that they were
      exercisable immediately prior to the date of such termination, subject,
      however, to the limitation set forth in subparagraph (g) above.

            (j) All numbers of shares set forth above or subject to any Option
      and all option prices, shall be subject to appropriate anti-dilution
      adjustment to take account of stock splits, stock dividends, merger,
      consolidation, reclassification or the like subsequent to the date hereof.

4. Termination. Notwithstanding the provisions of paragraph 1 hereof, the
employment of the Employee under this Agreement may be terminated in the
following circumstances:

            (a) BioCryst may terminate the employment of Employee hereunder
      immediately for "Cause" and without payment. "Cause" for termination of
      Employee's employment hereunder shall exist if Employee

                  (i)   shall confess to committing or shall be convicted of any
                        felony or any crime involving moral turpitude, or

                  (ii)  shall have engaged in gross and willful misconduct which
                        is materially injurious to the business of BioCryst.

            (b) BioCryst may terminate the employment of the Employee hereunder
      upon thirty (30) days written notice if the Employee shall have suffered a
      period of permanent disability, which shall for purposes of this Agreement
      be defined as the inability of Employee to perform his duties hereunder by
      reason of physical or mental incapacity for ninety (90) days, whether
      consecutive or not, during any consecutive twelve (12) month period.

      Upon such termination of employment, all rights of Employee to receive any
      future payments under paragraph 2 above shall cease.


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5. Non-Competition.

            (a) Non-Competition Agreement. The Employee agrees that for one (1)
      year following the termination of this Employment Agreement by reason of
      the voluntary termination by the Employee, without cause on the part of
      BioCryst, the Employee shall not become the Chief Executive Officer or
      become a key executive of another for-profit business enterprise whose
      activities are at such time directly competitive with BioCryst.

            (b) Equitable Remedies. Employee acknowledges and recognizes that a
      violation of this paragraph by Employee may cause irreparable and
      substantial damage and harm to BioCryst or its affiliates, could
      constitute a failure of consideration, and that money damages will not
      provide a full remedy for BioCryst for such violations. Employee agrees
      that in the event of his breach of this paragraph, BioCryst will be
      entitled, if it so elects, to institute and prosecute proceedings at law
      or in equity to obtain damages with respect to such breach, to enforce the
      specific performance of this paragraph by Employee, and to enjoin Employee
      from engaging in any activity in violation hereof.

6. Miscellaneous.

            (a) Entire Agreement. This Agreement, including the exhibits hereto,
      constitutes the entire agreement between the parties relating to the
      employment of the Employee by BioCryst and there are no terms relating to
      such employment other than those contained in this Agreement. No
      modification or variation hereof shall be deemed valid unless in writing
      and signed by the parties hereto. No waiver by either party of any
      provision or condition of this Agreement shall be deemed a waiver of
      similar or dissimilar provisions or conditions at any time.

            (b) Assignability. This Agreement may not be assigned without prior
      written consent of the parties hereto. To the extent allowable pursuant to
      this Agreement, this Agreement shall be binding upon and shall inure to
      the benefit of each of the parties hereto and their respective executors,
      administrators, personal representatives, heirs, successors and assigns.

            (c) Notices. Any notice or other communication given or rendered
      hereunder by any party hereto shall be in writing and delivered personally
      or sent by registered or certified mail, postage prepaid, at the
      respective addresses of the parties hereto as set forth below.

            (d) Captions. The section headings contained herein are inserted
      only as a matter of convenience and reference and in no way define, limit
      or describe the scope of this Agreement or the intent of any provision
      hereof.

            (e) Taxes. All amounts to be paid to Employee hereunder are in the
      nature of compensation for Employee's employment by BioCryst, and shall be
      subject to withholding, income, occupation and payroll taxes and other
      charges applicable to such compensation.

            (f) Governing Law. This Agreement is made and shall be governed by
      and construed in accordance with the laws of the State of Alabama without
      respect to its conflicts of law principles.

            (g) Date. This Agreement is dated as of December 27, 1999.


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      If the foregoing correctly sets forth our understanding, please signify
your acceptance of such terms by executing this Agreement, thereby signifying
your assent, as indicated below.

                                Yours very truly,

                                    BIOCRYST PHARMACEUTICALS, INC.


                                    By: /s/ William W. Featheringill
`                                       ----------------------------------------

                                    Its: Chairman, Compensation Commitee
                                         ---------------------------------------
                                    Address:

                                    2190 Parkway Lake Drive
                                    --------------------------------------------

                                    Birmingham, Alabama 35244
                                    --------------------------------------------

      AGREED AND ACCEPTED, as of this 27th day of December_____________________,
1999.


                                    /s/ Charles E. Bugg
                                    --------------------------------------------
                                    Charles E. Bugg

                                    Address:

                                    4370 Cliff Road
                                    Birmingham, Alabama 35222


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