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                                                                    Exhibit 10.4

                                                                  EXECUTION COPY

                                    AGREEMENT

                                     BETWEEN

                        MOUNT SINAI SCHOOL OF MEDICINE OF
                               NEW YORK UNIVERSITY

                                       AND

                            AMICUS THERAPEUTICS, INC.

LICENSE AGREEMENT

This License Agreement (the "Agreement") is made and effective as of April 15,
2002 (the "Effective Date"), by and between:

MOUNT SINAI SCHOOL OF MEDICINE OF NEW YORK UNIVERSITY, a corporation organized
and existing under the laws of the State of New York and having a place of
business at One Gustave L. Levy Place, New York, NY 10029 ("MSSM")

AND

Amicus Therapeutics, Inc., a corporation duly organized and existing under the
laws of Delaware, and having its principal office at 1055 Washington Blvd.,
Stamford, Connecticut 06901, c/o CHL Medical Partners, L.P. ("AMICUS").

RECITALS

WHEREAS:

MSSM has an ownership interest in certain Patent Rights (as hereinafter
defined); and

AMICUS wishes to obtain a license to manufacture, use, sell and offer for sale
the products covered by the Patent Rights and MSSM desires to grant such
license, all on the terms and conditions set forth herein.

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      TREATMENT HAS BEEN REQUESTED. ALL SUCH OMITTED MATERIAL HAS BEEN FILED
      WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO RULE 24b-2
      PROMULGATED UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.
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NOW, THEREFORE, IT IS HEREBY DECLARED AND AGREED BETWEEN THE PARTIES AS FOLLOWS:

1.   Definitions.

Whenever used in this Agreement, the following terms shall have the following
meanings:

     a.   "Affiliate" shall mean any corporation, firm, limited liability
          company, partnership or other entity that directly or indirectly
          controls or is controlled by or is under common control with a party
          to this Agreement. "Control" means ownership, directly or through one
          or more Affiliates, of 50 percent or more of the shares of stock
          entitled to vote for the election of directors, in the case of a
          corporation, or 50 percent or more of the equity interests in the case
          of any other type of legal entity, status as a general partner in any
          partnership, or any other arrangement whereby a party controls or has
          the right to control the board of directors or equivalent governing
          body of a corporation or other entity.

     b.   "Calendar Year" shall mean any consecutive period of twelve months
          commencing on the first day of January of any year.

     c.   "Chaperones" shall mean [***].

     d.   "Conformational Diseases" shall mean [***].

     e.   "Field" shall mean [***].

     f.   "License" shall mean the license under the Patent Rights to develop,
          manufacture, have manufactured, use, offer for sale and sell the
          Licensed Products as provided in Article 2, below.

     g.   "Licensed Product" shall mean any product or part thereof, the
          manufacture, use, or sale of which is: (i) covered by one or more
          Valid Claims of any Patent Rights, or (ii) which could not be
          developed, manufactured, used, sold, comprised or delivered without
          the Patent Rights.

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      TREATMENT HAS BEEN REQUESTED. ALL SUCH OMITTED MATERIAL HAS BEEN FILED
      WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO RULE 24b-2
      PROMULGATED UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.


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     h.   "Net Sales" shall mean the total amount invoiced by AMICUS or by any
          AMICUS Affiliate or sub-licensee of AMICUS in connection with sales to
          any purchaser of the Licensed Products that is not an Affiliate or a
          sub-licensee of AMICUS or an AMICUS Affiliate, after deduction of all
          the following to the extent applicable to such sales;

          i)   trade, cash and quantity credits, discounts, refunds or rebates;

          ii)  allowances or credits for returns;

          iii) sales commissions;

          iv)  sales taxes (including value added tax), and

          v)   freight and insurance charges borne by the seller.

      i.  "Patent Rights" shall mean any issued patent or any patent to be
          issued pursuant to any United States or foreign patent application
          owned, by MSSM, listed in this subclause 1.i.(i)-(v) together with any
          continuations in whole or in part, divisional or substitute patents,
          any reissues or re-examinations of any such application or patents,
          and any extension of the term of any such patent in the Field. The
          issued patents and patent applications referred to in the preceding
          sentence are:

               i)   U.S. Pat. No. 6,274,597- "Method of Enhancing Lysosomal
                    AlphaGalA";

               ii)  U.S. Pat. Applic. No. 09/604,053 (continuation in part) -
                    "Method of Enhancing Mutant enzyme activities in lysosomal
                    storage disease";

               iii) U.S. Pat. Applic. No. 09/926,285 (continuation of the '597
                    Patent; and

               iv)  U.S. Pat. Applic. No. 09/948,348 (continuation of the '053
                    CIP Application.

               v)   U.S. Pat. Applic. entitled "Screen for active site specific
                    chaperones for enhancing protein folding of mutant proteins"
                    filed on March 1, 2002.

     j.   "Valid Claim" shall mean a claim of (i) an issued patent included in
          the Patent Rights which has not been declared invalid in a final,
          unappealable decision of a court of appropriate jurisdiction, or (ii)
          a pending patent application included in the Patent Rights which is
          being diligently prosecuted by or on behalf of MSSM and has not been
          formally terminated or abandoned without issuance of a patent.

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      TREATMENT HAS BEEN REQUESTED. ALL SUCH OMITTED MATERIAL HAS BEEN FILED
      WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO RULE 24b-2
      PROMULGATED UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.


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2.   The License

     a.   Subject to the terms and conditions hereinafter set forth, MSSM hereby
          grants to AMICUS and AMICUS hereby accepts from MSSM the world-wide
          right under the Patent Rights to develop Licensed Products for use in
          the Field and to manufacture, use, sell and offer for sale the
          Licensed Products for use in the Field. Except as set forth in Section
          2e and 8f the License shall be exclusive as to all rights of MSSM in
          and to the Patent Rights. During the term of this Agreement, MSSM
          shall make no further grant of rights in and to the Patent Rights
          inconsistent with the rights of AMICUS herein.

     b.   AMICUS shall be entitled to grant sub-licenses under the License on
          terms and conditions not inconsistent with this Agreement (except that
          the rate of royalty may be at higher rates than those set forth in
          this Agreement): (i) to an Affiliate, and (ii) to other third parties
          for consideration and in arms-length transactions.

     c.   All sub-licenses shall only be granted by AMICUS pursuant to a written
          agreement, a true and complete copy of which shall be submitted by
          AMICUS to MSSM as soon as practicable after the signing thereof. Each
          sub-license granted by AMICUS hereunder shall be subject and
          subordinate to the terms and conditions of this License Agreement and
          shall contain, inter alia, the following provisions:

          i)   the sub-license shall expire automatically on the termination of
               the License;

          ii)  the sub-license shall not be assignable, in whole or in part;

          iii) the sub-licensee shall not be entitled to grant further
               sub-licenses; and

          iv)  both during the term of the sub-license and thereafter the
               sub-licensee shall be bound by a secrecy obligation similar to
               that imposed on AMICUS in Section 6 below, and that the
               sub-licensee shall bind its employees and agents, both during the
               terms of their employment and thereafter, with a similar
               undertaking of secrecy.

     d.   The sub-license agreement shall also include the text of Sections 6, 9
          and 10 of this Agreement and shall state that MSSM is an intended
          third party beneficiary of such sub-license agreement for purposes of
          enforcing such indemnification and insurance provisions.

     e.   The License shall be subject to (i) a non-exclusive license in favor
          of the U.S. Government to the extent required by Title 35 U.S.C.A.
          Section 200 et seq., or as otherwise required by virtue of use of
          federal funding in support of inventions claimed within the Patent
          Rights and (ii) a right and license retained by MSSM on behalf of
          itself and its faculty, students and academic collaborators to
          practice the Patent Rights for its own bona fide research, including
          sponsored research and collaborations. The retained rights granted in
          this Section 2e shall not give

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      TREATMENT HAS BEEN REQUESTED. ALL SUCH OMITTED MATERIAL HAS BEEN FILED
      WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO RULE 24b-2
      PROMULGATED UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.


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          MSSM the right to offer or grant rights in the Field under the Patent
          Rights to third parties.

     f.   Except for the License expressly provided in this Section 2, neither
          party hereto will, as a result of this Agreement, obtain any ownership
          interest in, or any other right or license to, any existing
          technology, patents, or Confidential Information, as defined in
          Section 6, below, of the other party.

3.   Royalty

     a.   In consideration for the grant of the License hereunder, subject to
          the provisions of Section 3.b, (i) AMICUS shall pay to MSSM [***] on
          Net Sales; and (ii) in the event AMICUS grants sublicenses with
          respect to any Licensed Product pursuant to which AMICUS receives
          remuneration other than royalties, then AMICUS shall pay to MSSM [***]
          of all payments that AMICUS receives from such sublicensee or other
          parties, including, without limitation: (a) Contract Signature
          Payments, (b) Third Party Milestone Payments, or (c) Maintenance Fees.

          As used in this Section 3.a.(ii), the term "Contract Signature
          Payment" means license initiation fees and all other up-front
          payments made to AMICUS in connection with a sublicense or similar
          agreement; "Third Party Milestone Payments" means payments made to
          AMICUS upon fulfillment by AMICUS or the sub-licensee of designated
          development objectives or regulatory requirements; and "Maintenance
          Fees" means payments (such as annual minimum royalties) made by
          sub-licensees to AMICUS to preserve, or to avoid a forfeiture of
          rights under, the sublicense agreement;

          With respect to any sublicensing or other transaction to which this
          Section 3.a.(ii) applies but which relates to products and services in
          addition to Licensed Products and for which an allocation would be
          necessary, the parties shall meet and attempt to agree on which
          portion of the total payments received by AMICUS pursuant to such
          transaction would be subject to this Section 3.a.(ii). If the parties
          cannot agree upon such allocation within a reasonable period of time,
          AMICUS shall select a nationally recognized independent certified
          public accountant, which meets MSSM's approval, to determine such
          allocation. Such allocation shall be determined in accordance with
          generally accepted accounting principles in the United States.

     b.   If AMICUS is required to acquire one or more licenses from third
          parties to make, use or sell a Licensed Product such that aggregate
          royalties payable by AMICUS on Net Sales (including the royalty amount
          due to MSSM pursuant to Section 3.a) exceeds [***], then AMICUS shall
          be entitled to a credit against the royalty payments due to MSSM
          pursuant to Section 3.a equal to [***] of the amount of such excess;
          provided, however, that in no event shall the amount otherwise payable
          to MSSM be reduced to less than [***] of Net Sales.

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      TREATMENT HAS BEEN REQUESTED. ALL SUCH OMITTED MATERIAL HAS BEEN FILED
      WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO RULE 24b-2
      PROMULGATED UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.

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     c.   AMICUS shall notify MSSM of the date of the first commercial sale of a
          Licensed Product as soon as practicable after the making of such
          commercial sale.

     d.   Commencing on the date of first commercial sale of a License Product,
          AMICUS shall, within 90 days from the last day of each June and
          December in each Calendar Year during the term of the License, submit
          to MSSM a full and detailed report of royalties or payments due MSSM
          under the terms of this Agreement for the preceding half year (the
          "Semi-Annual Report"), setting forth the Net Sales and lump sum
          payments and all other payments or consideration from sublicensees
          upon which such royalties are computed and including, on a Licensed
          Product-by-Licensed Product basis at least:

          i)   the quantity of Licensed Products used, sold, transferred or
               otherwise disposed of,

          ii)  the selling price of each Licensed Product,

          iii) the deductions permitted to arrive at Net Sales,

          iv)  the royalty computations and deductions therefrom based on
               royalty payments to third parties.

          If no royalties are due, a statement shall be sent to MSSM stating
          such fact. The full amount of any royalties or other payments due to
          MSSM for the preceding half-year shall accompany each such report on
          royalties and payments. AMICUS and all its sub-licensees shall keep
          for a period of at least five years after the date of entry, full,
          accurate and complete books and records consistent with sound business
          and accounting practices and in such form and in such detail as to
          enable the determination of the amounts due to MSSM from AMICUS
          pursuant to terms of this Agreement.

     e.   At the request and expense of MSSM, AMICUS shall permit (and shall
          require its sub-licensees to permit) an independent certified or
          chartered public accountant appointed by MSSM, at reasonable times
          during normal business hours and upon reasonable notice, but in any
          event no more than once per calendar year, to examine the records of
          AMICUS (and its sub-licensees) to the extent necessary to verify
          royalty calculations made hereunder; provided, however, that such
          examination shall be at the expense of AMICUS if it reveals a
          discrepancy in the amount of royalties to be paid in MSSM's favor of
          more than five percent. Results of such examination shall be made
          available to both AMICUS and MSSM.

4.   Method of Payment

     a.   Royalties and any other payments due to MSSM hereunder shall be paid
          to MSSM in United States dollars.

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      TREATMENT HAS BEEN REQUESTED. ALL SUCH OMITTED MATERIAL HAS BEEN FILED
      WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO RULE 24b-2
      PROMULGATED UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.

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     b.   AMICUS shall be responsible for prompt payment to MSSM of all
          royalties due on sale, transfer or disposition of Licensed Products by
          the sub-licensees of AMICUS.

     c.   As to sales occurring in currencies other than U.S. Dollars, Net Sales
          shall first be calculated in the currency in which sale occurred and
          then converted to U.S. Dollars at the buying rate for such currency
          calculated as the average of the closing buying rate for the first and
          last business day of the six month period for which royalties are due,
          as set forth in the Wall Street Journal for such dates.

5.   Development and Commercialization

     a.   AMICUS shall use its commercially reasonable efforts to bring one or
          more Licensed Products to market through a thorough, vigorous and
          diligent program for exploitation of the Patent Rights in the Field.
          AMICUS shall not, however, be required to pursue the development of
          more than one Licensed Product at a time, nor shall AMICUS be required
          to pursue every possible Licensed Product.

     b.   Attached as Appendix A to this Agreement is the current development
          plan of AMICUS for the forthcoming period of twelve months (such plan,
          as updated from time to time as described in clause (c) below, the
          "Plan"). As and when appropriate, future Plans will incorporate
          efficacy, pharmaceutical safety, toxicological and/ or clinical tests
          or any other activities necessary in order to obtain the approval of
          the FDA and counterpart foreign regulatory agencies for the
          production, use and sale of Licensed Products, as well as marketing
          plans to commercialize Licensed Products that have obtained such
          approvals.

     c.   On the earlier of thirty (30) days prior to the first anniversary of
          the Effective Date or the end of AMICUS's first fiscal year, and
          thereafter on each successive anniversary of such date, AMICUS shall
          deliver to MSSM a report setting forth in reasonable detail progress
          and problems with the implementation of the Plan and, providing an
          update on its efforts to commercialize Licensed Products, including a
          forecast and schedule of major events required to market the Licensed
          Products. Such report shall also include any amendments proposed by
          AMICUS to the Plan based upon the progress made and then current
          scientific, regulatory and commercial exigencies relating to Licensed
          Products. Within forty-five (45) days following the delivery of such a
          report (a "Diligence Report") representatives of MSSM may request a
          meeting with AMICUS to review the Diligence Report, the status of the
          efforts of AMICUS under the Plan and any proposed amendments to the
          Plan. Any such proposed amendments to the Plan shall be subject to
          approval by MSSM, which approval shall not be unreasonably withheld or
          delayed. Upon approval of any such amendments, they shall be deemed
          amendments to the Plan, added to Appendix A and deemed incorporated
          into this Agreement.

     d.   AMICUS will use its commercially reasonable efforts to accomplish the
          milestones described in the Plan.

     e.   Provided that applicable laws, rules and regulations so require, the
          manufacture of Licensed Products shall be carried out by AMICUS or its
          agents in accordance

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      TREATMENT HAS BEEN REQUESTED. ALL SUCH OMITTED MATERIAL HAS BEEN FILED
      WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO RULE 24b-2
      PROMULGATED UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.

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          with FDA Good Laboratory Practices and FDA Good Manufacturing Practice
          ("GMP") procedures in a facility which has been certified by the FDA
          and the performance of the tests, trials, studies and other activities
          specified in the Plan shall be so performed by AMICUS or its agents in
          accordance with FDA clinical trial procedures. MSSM shall have no
          responsibility for the actual production, distribution, sale or use of
          any Licensed Product.

     f.   If at any time AMICUS abandons or suspends its efforts to
          commercialize all Licensed Products for a period exceeding ninety (90)
          days, AMICUS shall immediately notify MSSM giving reasons and a
          statement of its intended actions. MSSM shall be entitled to terminate
          this Agreement for "Cause" in accordance with Section 11 upon any such
          abandonement.

     g.   MSSM shall also be entitled to terminate this Agreement for "Cause" in
          accordance with Section 11 if AMICUS shall fail to deliver any
          Diligence Report on a timely basis, or fail to use commercially
          reasonable efforts to implement the Plan, and such failure is not
          cured within the sixty (60) day period set by the notice provided
          pursuant to Section 11, unless such failure is excused by:

          i)   causes beyond AMICUS's direct control; or

          ii)  MSSM's failure to meet its obligations hereunder; or

          iii) inaction of any federal or state agency whose approval is
               required for commercial sales of Licensed Products.

     h.   Provided that applicable laws, rules and regulations so require, the
          performance of the tests, trials, studies and other activities
          specified in subsection b, above, shall be carried out in accordance
          with FDA Good Laboratory Practices and FDA Good Manufacturing Practice
          ("GMP") procedures in a facility which has been certified by the FDA
          as complying with GMP. MSSM shall have no responsibility for the
          actual production, distribution, sale or use of any Licensed Product.

6.   Confidential Information.

     a.   In the course of research to be performed under this Agreement, it
          will be necessary for each party to disclose "Confidential
          Information" to the other. For purposes of this Agreement,
          "Confidential Information" is defined as all information, data and
          know-how disclosed by one party (the "Disclosing Party") to the other
          (the "Receiving Party"), either embodied in tangible materials
          (including writings, drawings, graphs, charts, photographs,
          recordings, structures, technical and other information) marked
          "Confidential" or, if initially disclosed orally, which is reduced to
          writing marked "Confidential" within 21 days after initial oral
          disclosure, other than that information which is:

          i)   known by the Receiving Party at the time of its receipt, and not
               through a prior disclosure by the Disclosing Party, as documented
               by the Receiving Party's business records; or

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      TREATMENT HAS BEEN REQUESTED. ALL SUCH OMITTED MATERIAL HAS BEEN FILED
      WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO RULE 24b-2
      PROMULGATED UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.

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          ii)  at the time of disclosure, or thereafter becomes, published or
               otherwise part of the public domain without breach of this
               Agreement by the Receiving Party; or

          iii) obtained from a third party who has the legal right to make such
               disclosure and without any confidentiality obligation to the
               Disclosing Party; or

          iv)  independently developed by the Receiving Party without the use of
               Confidential Information received from the Disclosing Party and
               such independent development can be documented by the Receiving
               Party; or

          v)   disclosed to governmental or other regulatory agencies in order
               to obtain patents, provided that such disclosure may be made only
               to the extent reasonably necessary to obtain such patents or
               authorizations, and further provided that any such patent
               applications shall be filed in accordance with the terms of this
               Agreement; or

          vi)  required by law, regulation, rule, act or order of any
               governmental authority to be disclosed.

     b.   The Receiving Party agrees that at all times and notwithstanding any
          termination, expiration, or cancellation hereunder, it will hold the
          Confidential Information of the Disclosing Party in strict confidence,
          will use all reasonable safeguards to prevent unauthorized disclosure
          by its employees and agents. Notwithstanding the foregoing, the
          parties recognize that industry standards with respect to the
          treatment of Confidential Information may not be appropriate in an
          academic setting. However, MSSM agrees to retain Confidential
          Information of AMICUS in the same manner and with the same level of
          confidentiality as MSSM retains its own Confidential Information.

     c.   The Receiving Party will maintain reasonable procedures to prevent
          accidental or other loss, including unauthorized publication of any
          Confidential Information of the Disclosing Party. The Receiving Party
          will promptly notify the Disclosing Party in the event of any loss or
          unauthorized disclosure of the Confidential Information.

     d.   Upon termination or expiration of this Agreement, and upon written
          request, the Receiving Party will promptly return to the Disclosing
          Party all documents or other tangible materials representing
          Confidential Information and all copies thereof.

     e.   The Receiving Party will immediately notify the Disclosing Party in
          writing, if it is requested by a court order, a governmental agency,
          or any other entity to disclose Confidential Information in the
          Receiving Party's possession. The Disclosing Party will have an
          opportunity to intervene by seeking a protective order or other
          similar order, in order to limit or prevent disclosure of the
          Confidential Information. The Receiving Party will disclose only the
          minimum

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      TREATMENT HAS BEEN REQUESTED. ALL SUCH OMITTED MATERIAL HAS BEEN FILED
      WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO RULE 24b-2
      PROMULGATED UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.

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          Confidential Information required to be disclosed in order to comply,
          whether or not a protective order or other similar order is obtained
          by the Disclosing Party.

7.   Patent Rights.

     a.   If either party to this Agreement acquires information that a third
          party is infringing one or more of the Patent Rights, the party
          acquiring such information shall promptly notify the other party to
          Agreement in writing of such infringement.

     b.   In the event of infringement of the Patent Rights, AMICUS shall have
          the right, but not the obligation, to bring suit against the
          infringer. Should AMICUS elect to bring suit against an infringer,
          AMICUS shall be entitled to retain counsel of its own choosing, and
          shall have the right to join MSSM as party plaintiff in any such suit.
          Except as otherwise provided herein, the expenses of such suit or
          suits that AMICUS elects to bring, shall be paid for entirely by
          AMICUS and AMICUS shall hold MSSM free, clear and harmless from and
          against any and all costs of such litigation, including attorneys'
          fees. AMICUS shall not compromise or settle such litigation without
          the prior written consent of MSSM which shall not be unreasonably
          withheld.

     c.   If AMICUS shall undertake the enforcement or defense of the Patent
          Rights by litigation, AMICUS may withhold royalties otherwise
          thereafter due MSSM hereunder and apply the same toward reimbursement
          of up to [***] of AMICUS's expenses, including reasonable attorney's
          fees, in connection therewith, provided however that the maximum
          amount that can be withheld each year shall not exceed [***] of
          royalties due to MSSM in that year.

     d.   If AMICUS exercises its right to sue, it shall first reimburse itself
          out of any sums recovered in such suit or in settlement thereof for
          all costs and expenses of every kind and character, including
          reasonable attorneys' fees, necessarily involved in the prosecution of
          any such suit, and if after such reimbursement, any funds shall remain
          from said recovery, the amount of said funds shall be added to the
          amount of Net Sales for the calendar quarter in which such recovery
          was made.

     e.   If AMICUS does not bring suit against said infringer pursuant to
          subsection b, above, or has not commenced negotiations with said
          infringer for discontinuance of said infringement, within 90 days
          after receipt of such notice, MSSM shall have the right, but not the
          obligation, to bring suit for such infringement and to join AMICUS as
          a party plaintiff, in which event MSSM shall hold AMICUS free, clear
          and harmless from and against any and all costs and expenses of such
          litigation, including attorneys' fees. In the event MSSM brings suit
          for infringement of the Patent Rights, MSSM shall have the right to
          first reimburse itself out of any sums recovered in such suit or
          settlement thereof for all costs and expenses of every kind and
          character, including reasonable attorneys' fees necessarily involved
          in the prosecution of such suit, and if after such reimbursement, any
          funds shall remain from said recovery, MSSM shall promptly pay to
          AMICUS an amount equal to [***] percent of such remainder and MSSM
          shall be entitled to receive and retain the balance of the remainder
          of such recovery.

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      TREATMENT HAS BEEN REQUESTED. ALL SUCH OMITTED MATERIAL HAS BEEN FILED
      WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO RULE 24b-2
      PROMULGATED UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.

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     f.   Each party shall have the right to be represented by counsel of its
          own selection, at its sole expense, in any suit for infringement of
          the Patent Rights instituted by the other party to this Agreement
          under the terms hereof.

     g.   AMICUS shall cooperate fully with MSSM at the request of MSSM,
          including, by giving testimony and producing documents lawfully
          requested in the course of a suit prosecuted by MSSM for infringement
          of the Patent Rights; provided MSSM shall pay all reasonable expenses
          (including attorneys' fees) incurred by AMICUS in connection with such
          cooperation. MSSM shall cooperate with AMICUS in the prosecution of a
          suit by AMICUS for infringement of the Patent Rights, provided that,
          except as otherwise provided in Section 7.f., AMICUS shall pay all
          reasonable expenses (including attorneys' fees) involved in such
          cooperation.

     h.   AMICUS shall, upon receipt of reasonable documentation, promptly
          reimburse MSSM for all of the reasonable and customary fees and
          expenses incurred by MSSM as of the Effective Date, which the parties
          expect to be approximately [***], in the prosecution and maintenance
          of the Patent Rights. In addition, AMICUS will reimburse MSSM, within
          30 days of the execution of this agreement, for [***] in total
          payments to [***] and [***] pursuant to the letter of agreement dated
          March 24, 2000 between MSSM and [***] and [***].

8.   Patent Prosecution

     a.   MSSM is the owner of the Patent Rights. MSSM has retained Darby and
          Darby, PC to prepare, file, prosecute, and maintain the pending patent
          applications and issued patents comprising the Patent Rights.

     b.   MSSM shall maintain an attorney-client relationship with Darby and
          Darby (or other patent counsel mutually agreed to by both parties
          ("Law Firm")) with respect to the Patent Rights. Nothing in this
          agreement shall prevent Amicus from establishing an attorney client
          relationship with Law Firm, except that nothing herein shall authorize
          or permit Law Firm to take any action for, or on behalf of Amicus that
          would be adverse to MSSM and/or involve a conflict of interest or a
          violation of the Code of Professional Responsibility.

     c.   From and after the Effective Date, Law Firm will interact directly
          with Amicus on all patent prosecution and patent maintenance matters
          related to the Patent Rights. Amicus shall request that the Law Firm
          send to MSSM:

               i) Copies of any document pertaining to the ongoing prosecution
               of the Patent Rights received from the U.S. Patent and Trademark
               Office, within ten (10) business days after such receipt; and

               ii) Copies of any document to be submitted to the U.S. Patent and
               Trademark Office (or any other patent granting authority) in any
               such patents or applications, at least ten (10) business days
               prior to the date

[***] INDICATES MATERIAL THAT HAS BEEN OMITTED AND FOR WHICH CONFIDENTIAL
      TREATMENT HAS BEEN REQUESTED. ALL SUCH OMITTED MATERIAL HAS BEEN FILED
      WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO RULE 24b-2
      PROMULGATED UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.

                                       11

<PAGE>

               on which such document is mailed to such patent office or
               granting authority and at least twenty (20) days prior to such
               mailing date for responses to Patent Office action for which the
               Patent and Trademark Office accords a response period of more
               than thirty (30) days. Amicus shall request that Law Firm, using
               their professional judgment, accept reasonable changes that MSSM
               communicates to such counsel if such request for changes are
               received by Amicus more than five (5) business days prior to the
               date on which such document is due at the patent granting
               authority. The time limits contained in this Section 8.c.ii shall
               not apply if the application of the time allowed herein would
               create an imminent bar to patentability.

     d.   Prior to abandoning prosecution of any of the Patent Rights (or to
          abandoning any patent) covered by this Agreement, Amicus will:

               i) Notify MSSM of its intention to abandon such patent or
               application(s) at least twenty (20) days prior to the last date
               for taking action to preserve such patent or applications(s);

               ii) Permit Law Firm to continue prosecution and/or maintenance of
               such patent or application at MSSM's sole expense.

     e.   Except as otherwise expressly provided herein, Amicus shall bear all
          costs and fees incurred during the term of this Agreement in
          connection with the filing, maintenance, prosecution, protection and
          the like of the Patent Rights. Law Firm shall invoice AMICUS directly
          for all work relating to the filing, prosecution and maintenance of
          the Patent Rights and shall provide copies of all invoices to MSSM.
          AMICUS will pay invoices directly to Law Firm and copy MSSM on each
          payment.

     f.   If at any time during the term of this Agreement AMICUS decides that
          it is undesirable, as to one or more countries, to prosecute or
          maintain any patents or patent applications within the Patent Rights,
          it shall give prompt written notice thereof to MSSM, and upon receipt
          of such notice AMICUS shall be released from its obligations to bear
          all of the expenses to be incurred thereafter as to such countries in
          conjunction with such patent(s) or patent application(s). MSSM shall
          be free to grant rights in and to the released patent or patent
          applications in such countries to third parties, without further
          notice or obligation to AMICUS, and AMICUS shall have no rights
          whatsoever to exploit the released patents or patent applications in
          such countries.

     g.   Notwithstanding the foregoing, MSSM reserves the absolute right to
          countermand any instruction given by Amicus to Law Firm with respect
          to the Patent Rights.

     h.   Nothing herein contained shall be deemed to be a warranty by MSSM that
          the manufacture, use, or sale of any element of the Patent Rights or
          any Licensed Product will not infringe any patent(s) of a third party.

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      TREATMENT HAS BEEN REQUESTED. ALL SUCH OMITTED MATERIAL HAS BEEN FILED
      WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO RULE 24b-2
      PROMULGATED UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.

                                       12

<PAGE>

9.   Liability and Indemnification.

     a.   AMICUS shall indemnify, defend and hold harmless MSSM and its
          trustees, officers, directors, medical and professional staff,
          employees, students and agents and their respective successors, heirs
          and assigns (the "Indemnitees"), against any liability, damage, loss
          or expense (including reasonable attorneys' fees and expenses of
          litigation) incurred by or imposed upon the Indemnitees or any one of
          them in connection with any claims, suits, actions, demands or
          judgments: (i) arising out of the production, manufacture, sale, use
          in commerce or in human clinical trials, lease, or promotion by AMICUS
          or by a licensee, Affiliate or agent of AMICUS of any Licensed
          Product, process or service relating to, or developed pursuant to,
          this Agreement, or (ii) arising out of any other activities to be
          carried out pursuant to this Agreement.

     b.   AMICUS's indemnification under subsection a(i), above, shall apply to
          any liability, damage, loss or expense whether or not it is
          attributable to the negligent activities of the Indemnitees. AMICUS's
          indemnification under subsection a (ii), above, shall not apply to any
          liability, damage, loss or expense to the extent that it is
          attributable to the negligence, gross negligence or intentional
          misconduct of the Indemnitees.

     c.   AMICUS shall, at its own expense, provide attorneys reasonably
          acceptable to MSSM to defend against any actions brought or filed
          against any party indemnified hereunder with respect to the subject of
          indemnity contained herein, whether or not such actions are rightfully
          brought.

     d.   EXCEPT AS PROVIDED IN THIS SECTION 9, NEITHER PARTY SHALL BE LIABLE TO
          THE OTHER FOR INCIDENTAL, CONSEQUENTIAL, SPECIAL, EXEMPLARY OR
          PUNITIVE DAMAGES.

10.  Security for Indemnification.

     a.   At such time as any Licensed Product is being commercially distributed
          or sold (other than for the purpose of obtaining regulatory approvals)
          by AMICUS or by a sub-licensee, Affiliate or agent of AMICUS and to
          the extent that it is available on commercially reasonable terms,
          AMICUS shall at its sole cost and expense, procure and maintain
          policies of comprehensive general liability insurance in amounts not
          less than [***] per incident and [***] annual aggregate and naming the
          indemnitees as additional insureds. Such comprehensive general
          liability insurance shall provide (i) product liability coverage and
          (ii) broad form contractual liability coverage for AMICUS's
          indemnification under Section 9 of this Agreement. The minimum amounts
          of insurance coverage required under this Section 10 shall not be
          construed as a limit of AMICUS's liability with respect to its
          indemnification under Section 9 of this Agreement.

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      TREATMENT HAS BEEN REQUESTED. ALL SUCH OMITTED MATERIAL HAS BEEN FILED
      WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO RULE 24b-2
      PROMULGATED UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.

                                       13

<PAGE>

     b.   AMICUS shall provide MSSM with written evidence of such insurance upon
          request of MSSM. AMICUS shall provide MSSM with written notice at
          least 60 days prior to the cancellation, non-renewal or material
          change in such insurance; if AMICUS does not obtain replacement
          insurance providing comparable coverage within such 60 day period
          effective immediately upon notice to AMICUS, MSSM shall have the right
          to terminate this Agreement effective at the end of such 60 day period
          without notice or any additional waiting periods.

     c.   AMICUS shall maintain such comprehensive general liability insurance
          beyond the expiration or termination of this Agreement during: (i) the
          period that any product, process or service, relating to, or developed
          pursuant to, this Agreement is being commercially distributed or sold
          (other than for the purpose of obtaining regulatory approvals) by
          AMICUS or by a licensee, Affiliate or agent of AMICUS and (ii) a
          reasonable period after the period referred to in (c)(i) above which
          in no event shall be less than seven years.

11.  Term and Termination.

     a.   This Agreement shall come into force as of the Effective Date. Unless
          sooner terminated as provided herein, this Agreement shall expire on
          the expiration of the last to expire of the Patent Rights.

     b.   At any time prior to expiration of the term of this Agreement either
          party may terminate this Agreement forthwith for cause upon notice to
          the other party. "Cause" for termination of this Agreement shall be
          deemed to exist if either MSSM or AMICUS materially breaches or
          defaults in the performance or observance of any of the provisions of
          this Agreement and such breach or default is not cured within 60 days
          or, in the case of failure to pay any amounts due hereunder, 30 days
          (unless otherwise specified herein) after the giving of notice by the
          other party specifying such breach or default, or if either MSSM or
          AMICUS discontinues its business or becomes insolvent or bankrupt.

     c.   Any amount payable hereunder by one of the parties to the other, which
          has not been paid by its due date of payment shall bear interest from
          its due date of payment until the date of actual payment, at the rate
          of two percent per annum in excess of the Prime Rate prevailing at the
          Citibank, Inc., New York, New York, during the period of arrears and
          such amount and the interest thereon may be set off against any amount
          due, whether in terms of this Agreement or otherwise, to the party in
          default by any non-defaulting party.

     d.   Upon termination of this Agreement for any reason, all rights in and
          to the Patent Rights shall revert to MSSM.

     e.   Termination of this Agreement shall not relieve the parties of any
          obligation occurring prior to such termination.

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      TREATMENT HAS BEEN REQUESTED. ALL SUCH OMITTED MATERIAL HAS BEEN FILED
      WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO RULE 24b-2
      PROMULGATED UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.

                                       14

<PAGE>

     f.   Sections 2e., 3e., 6, 9, 10 and 14 hereof shall survive and remain in
          full force and effect after any termination, cancellation or
          expiration of this Agreement.

12.  Representation and Covenants

     a.   MSSM hereby represents, warrants, and covenants to AMICUS that it is a
          corporation duly organized and validly existing under the laws of the
          state or other jurisdiction of its incorporation or formation;

     a.   AMICUS hereby represents, warrants and covenants to the other party
          hereto that it is a corporation duly organized and validly existing
          under the laws of the state or other jurisdiction of its incorporation
          or formation;

     b.   Each of MSSM and AMICUS hereby represents, warrants and covenants to
          the other party hereto as follows:

          i) the execution, delivery and performance of this Agreement by such
          party has been duly authorized by all requisite corporate action;

          ii) it has the power and authority to execute and deliver this
          Agreement and to perform its obligations hereunder;

          iii) the execution, delivery and performance by such party of this
          Agreement and its compliance with the terms and provisions hereof is
          not prohibited and does not and will result in a breach of any of the
          terms and provisions of, or constitute a default under, (i) a loan
          agreement, guaranty, financing agreement, agreement affecting a
          product, or other agreement or instrument binding or affecting it or
          its property; (ii) the provisions of its charter documents or bylaws;
          or (iii) any order, writ, injunction or decree of any court or
          governmental authority entered against it or by which any of its
          property is bound;

          iv) the execution, delivery and performance of this Agreement by such
          party does not require the consent, approval, or authorization of, or
          notice, declaration, filing or registration with, any governmental or
          regulatory authority, and the execution, delivery or performance of
          this Agreement will not violate any law, rule or regulation applicable
          to such party;

          v) this Agreement has been duly authorized, executed and delivered and
          constitutes such party's legal, valid and binding obligation
          enforceable against it in accordance with its terms subject, as to
          enforcement, to bankruptcy, insolvency, reorganization and other laws
          of general applicability relating to or affecting creditors' rights
          and to the availability of particular remedies under general equity
          principles; and

          vi) it shall comply with all applicable material laws and regulations
          relating to its activities under this Agreement.

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      TREATMENT HAS BEEN REQUESTED. ALL SUCH OMITTED MATERIAL HAS BEEN FILED
      WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO RULE 24b-2
      PROMULGATED UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.

                                       15

<PAGE>

          vii) Each party represents that performance of all the terms of this
               Agreement will not breach any agreement to keep in confidence
               proprietary information acquired by a party prior to the
               execution of this Agreement.

     c.   Except as otherwise expressly provided herein, MSSM hereby represents,
          warrants and covenants to AMICUS that:

          i)   MSSM has the full right, power and authority to grant all of the
               right, title and interest in the License; and

          ii)  there are no judgments or settlements against or owed by MSSM, or
               any pending or threatened claims or litigation relating to MSSM's
               interest in the Patent Rights; and

          iii) MSSM has not granted to any other party any rights that would
               conflict with the rights granted in this Agreement.

13.  Assignment.

     Neither party shall have the right to assign, delegate or transfer at any
     time to any party, in whole or in part, any or all of the rights, duties
     and interest herein granted without first obtaining the written consent of
     the other party to such assignment, such consent not to be unreasonably
     withheld; provided, however, that AMICUS may, with thirty (30) days prior
     written notice to MSSM, assign its rights and delegate its duties under the
     Agreement to the purchaser of substantially all of the assets of AMICUS,
     provided that the assignee agrees in writing to be bound by all the terms
     and conditions of this Agreement.

14.  Use of Name.

     Neither party may use the name of the other or its Affiliates in any
     publicity or advertising. A party may issue a press release or otherwise
     publicize or disclose this Agreement or the confidential terms and
     conditions hereof only with the prior written consent of the other party.

15.  Miscellaneous.

     a.   In carrying out this Agreement the parties shall comply with all
          local, state and federal laws and regulations including but not
          limited to, the provisions of Title 35 U.S.C.A. Section 200 et seq.
          and 15 CFR Section 368 et seq.

     b.   If any provision of this Agreement is determined to be invalid or
          void, the remaining provisions shall remain in effect.

[***] INDICATES MATERIAL THAT HAS BEEN OMITTED AND FOR WHICH CONFIDENTIAL
      TREATMENT HAS BEEN REQUESTED. ALL SUCH OMITTED MATERIAL HAS BEEN FILED
      WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO RULE 24b-2
      PROMULGATED UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.

                                       16

<PAGE>

     c.   This Agreement shall be deemed to have been made in the State of New
          York and shall be governed and interpreted in all respects under the
          laws of the State of New York. Any and all disputes hereunder shall be
          brought and resolved solely in the courts of the State of New York in
          and for the Borough of Manhattan.

     d.   All payments or notices required or permitted to be given under this
          agreement shall be given in writing and shall be effective when either
          personally delivered or deposited, postage prepaid, in the United
          States registered or certified mail, addressed as follows:

          To MSSM:   Mount Sinai School of Medicine of New York University
                     Attention: W. Patrick McGrath, Ph.D.
                     One Gustave L. Levy Place
                     New York, New York 10029-6574

          Copy to:   General Counsel (at the same address)

          To AMICUS: Amicus Therapeutics, Inc.
                     c/o Collinson Howe & Lennox, LLC
                     1055 Washington Blvd.
                     Stamford, CT 06901
                     Attention: Gregory Weinhoff, MD

          or such other address or addresses as either party may hereafter
          specify by written notice to the other. Such notices and
          communications shall be deemed to have been received by the addresses
          on the date of delivery if personally delivered or 14 days after
          having been sent by registered mail.

     e.   This Agreement and the exhibits attached hereto constitute the entire
          Agreement between the parties with respect to the subject matter
          hereof and no variations, modification or waiver of any of the terms
          or conditions hereof shall be deemed valid unless made in writing and
          signed by both parties hereto. This Agreement supersedes any and all
          prior agreements or understandings, whether oral or written, between
          AMICUS and MSSM.

     f.   No waiver by either party of any non-performance or violation by the
          other party of any of the covenants, obligations or agreements of such
          other party hereunder shall be deemed to be a waiver of any subsequent
          violation or non-performance of the same or any other covenant,
          agreement or obligation, nor shall forbearance by any party be deemed
          to be a waiver by such party of its rights or remedies with respect to
          such violation or non-performance.

     g.   The descriptive headings contained in this Agreement are included for
          convenience and reference only and shall not be held to expand, modify
          or aid in the interpretation, construction or meaning of this
          Agreement.

     h.   It is not the intent of the parties to create a partnership or joint
          venture or to assume partnership responsibility or liability. The
          obligations of the parties shall

[***] INDICATES MATERIAL THAT HAS BEEN OMITTED AND FOR WHICH CONFIDENTIAL
      TREATMENT HAS BEEN REQUESTED. ALL SUCH OMITTED MATERIAL HAS BEEN FILED
      WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO RULE 24b-2
      PROMULGATED UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.


                                       17

<PAGE>

          be limited to those set out herein and such obligations shall be
          several and not joint.

IN WITNESS WHEREOF, the parties hereto have executed this Agreement as of the
date first above written.

MOUNT SINAI SCHOOL OF MEDICINE          AMICUS THERAPEUTICS, INC.
OF NEW YORK UNIVERSITY


By:  /s/ Nathan Kase                    By:  /s/ Gregory Weinhoff
    ---------------------------------       ------------------------------------
Name:  Nathan Kase, M.D.                Name: Gregory M. Weinhoff
      -------------------------------
Title:  Interim Dean                    Title: Chief Executive Officer
       ------------------------------
Date:  4-15-02                          Date: April 15, 2002
      -------------------------------

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      TREATMENT HAS BEEN REQUESTED. ALL SUCH OMITTED MATERIAL HAS BEEN FILED
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      PROMULGATED UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.

                                       18

<PAGE>

                         AMENDMENT TO LICENSE AGREEMENT
                              DATED APRIL 15, 2002
                                     BETWEEN
                    MOUNT SINAI SCHOOL OF NEW YORK UNIVERSITY
                          AND AMICUS THERAPEUTICS INC.

Whereas the Mount Sinai School of Medicine of New York University (MSSM) and
Amicus Therapeutics Inc. (AMICUS) desire to make amendments to the License
Agreement between the two parties dated April 15, 2002.

NOW THEREFORE, IT IS HEREBY DECLARED AND AGREED BETWEEN THE PARTIES THAT THE
FOLLOWING AMENDMENTS TO THE LICENSE AGREEMENT BE EFFECTIVE AS OF ______________:

1. Under Section 1 (Definitions) the definition of "Patent Rights" shall be
amended to the following:

     i.   "Patent Rights" shall mean any issued patent or any patent to be
          issued pursuant to any United States or foreign patent application
          owned, by MSSM, listed in this subclause 1.i.(i)-(v) together with any
          continuations in whole or in part, divisional or substitute patents,
          any reissues or re-examinations of any such application or patents,
          and any extension of the term of any such patent in the Field. The
          issued patents and patent applications referred to in the preceding
          sentence are:

               i) U.S. Pat. No. 6,274,597-"Method of Enhancing Lysosomal
               AlphaGalA";

               ii) U.S. Pat. Applic. No. 09/604,053 (continuation in part)-
               "Method of Enhancing Mutant enzyme activities in lysosomal
               storage disease";

               iii) U.S. Pat. Applic. No. 09/926,285 (continuation of the '597
               Patent; and

               iv) U.S. Pat. Applic. No. 09/948,348 (continuation of the '053
               CIP Application.

               v) U.S. Pat. Applic. entitled "Screen for active site specific
               chaperones for enhancing protein folding of mutant proteins"
               filed on February 28, 2003.

               vi) US provisional patent application entitled "Combination
               Therapy For Treating Protein Deficiencies( )" filed on January
               31, 2003

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      TREATMENT HAS BEEN REQUESTED. ALL SUCH OMITTED MATERIAL HAS BEEN FILED
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      PROMULGATED UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.
<PAGE>

               vii) US provisional patent application entitled "Combination
               Therapy For Treating Protein Deficiencies" filed on February 18,
               2003

All other terms and conditions of the License Agreement remain unchanged and in
full force and effect.

MOUNT SINAI SCHOOL OF MEDICINE          AMICUS THERAPEUTICS, INC.
OF NEW YORK UNIVERSITY


By: /s/ Kenneth L. Davis                By: /s/ Norman Hardman
    ---------------------------------       ------------------------------------
Name: Kenneth L. Davis, M.D.            Name: Norman Hardman, Ph.D.
Title: Dean                             Title: President and CEO

Date: 3-13-03                           Date: 4.8.2003

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      TREATMENT HAS BEEN REQUESTED. ALL SUCH OMITTED MATERIAL HAS BEEN FILED
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      PROMULGATED UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.
<PAGE>
                                                                  Execution Copy


                         MOUNT SINAI SCHOOL OF MEDICINE
                 One Gustave L. Levy Place, New York, NY 10029


April 8, 2004


Amicus Therapeutics, Inc.
675 U.S. Highway One
North Brunswick, NJ 08902


Re:  Agreement between Mount Sinai School of Medicine of New York University
     ("MSSM") and Amicus Therapeutics, Inc. ("AMICUS") dated as of April 15,
     2002 (the "License Agreement)


Gentlemen:

This will confirm the agreement and understanding between MSSM and AMICUS
regarding an amendment to the License Agreement as follows:

1.   The definition of "Conformational Diseases" contained in Section 1.d. of
     the License Agreement is hereby amended in its entirety to read as follows:

     "Conformational Diseases" shall mean [***]

2.   The definition of "Field" contained in Section 1.e. of the License
     Agreement is hereby amended in its entirety to read as follows:

     "Field" shall mean





                         [***] INDICATES MATERIAL THAT HAS BEEN OMITTED AND FOR
                         WHICH CONFIDENTIAL TREATMENT HAS BEEN REQUESTED. ALL
                         SUCH OMITTED MATERIAL HAS BEEN FILED WITH THE
                         SECURITIES AND EXCHANGE COMMISSION PURSUANT TO RULE
                         24b-2 PROMULGATED UNDER THE SECURITIES EXCHANGE ACT
                         OF 1934, AS AMENDED
<PAGE>
Amicus Therapeutics, Inc.
April 8, 2004
Page 2




     [***]

3.   Section 2.c ii) of the License Agreement is hereby amended in its entirety
     to read as follows:

     2.c. ii)  the sub-license shall not be assignable, in whole or in part;
               provided, however, that the sublicensee may, written notice to
               MSSM, assign the sub-license in connection with a merger or
               acquisition of the sub-licensee or the sale by the sublicensee of
               substantially all of its assets;

4.   Section 13 of the License Agreement is hereby amended in its entirety to
     read as follows:

     Neither party shall have the right to assign, delegate or transfer at any
     time to any party, in whole or in part, any or all of the rights, duties
     and interest herein granted without first obtaining the written consent of
     the other party to such assignment, such consent not to be unreasonably
     withheld; provided, however, that AMICUS may, with written notice to MSSM,
     assign its rights and delegate its duties under the Agreement to a
     successor in interest of AMICUS by virtue of merger or acquisition or to
     the purchaser of substantially all of the assets of AMICUS, provided that
     the assignee agrees in writing to be bound by all the terms and conditions
     of this Agreement.

5.   MSSM hereby confirms that "Contract Signature Payments" and "Third Party
     Milestone Payments" as such terms are used in the License Agreement
     excludes (i) payment or reimbursement for patent expenses incurred by
     AMICUS, (ii) payment or reimbursement for the costs of research or
     development conducted by AMICUS that is sponsored by third parties or (iii)
     purchases by third parties of AMICUS securities.

6.   Except as expressly modified by this Amendment, all terms and conditions of
     the License Agreement shall remain in full force and effect.





                         [***] INDICATES MATERIAL THAT HAS BEEN OMITTED AND FOR
                         WHICH CONFIDENTIAL TREATMENT HAS BEEN REQUESTED. ALL
                         SUCH OMITTED MATERIAL HAS BEEN FILED WITH THE
                         SECURITIES AND EXCHANGE COMMISSION PURSUANT TO RULE
                         24b-2 PROMULGATED UNDER THE SECURITIES EXCHANGE ACT
                         OF 1934, AS AMENDED

<PAGE>
Amicus Therapeutics, Inc.
April 8, 2004
Page 3




Please indicate your acceptance of and agreement with the foregoing in the space
provided below.

Very truly yours,

Mount Sinai School of Medicine
of New York University

By:
     ------------------------
     Name:
     Title:

ACCEPTED AND AGREED

Amicus Therapeutics, Inc.

By:
     ------------------------
     Name:
     Title:










                         [***] INDICATES MATERIAL THAT HAS BEEN OMITTED AND FOR
                         WHICH CONFIDENTIAL TREATMENT HAS BEEN REQUESTED. ALL
                         SUCH OMITTED MATERIAL HAS BEEN FILED WITH THE
                         SECURITIES AND EXCHANGE COMMISSION PURSUANT TO RULE
                         24b-2 PROMULGATED UNDER THE SECURITIES EXCHANGE ACT
                         OF 1934, AS AMENDED