Exhibit 2.2



                                   ANNEX A-1


                               AMENDING AGREEMENT


     This AMENDING  AGREEMENT (this  "Agreement") is made and entered into as of
May 16, 2002, among BIOMARIN  PHARMACEUTICAL  INC.  ("BioMarin"),  a corporation
existing under the laws of Delaware, BIOMARIN ACQUISITION (NOVA SCOTIA) COMPANY,
an unlimited  liability  company  existing under the Companies Act (Nova Scotia)
and a wholly owned  Subsidiary  of BioMarin  ("BioMarin  Nova Scotia") and GLYKO
BIOMEDICAL LTD., a corporation existing under the laws of Canada ("Glyko").


                                    RECITALS

         A.       BioMarin,  BioMarin Nova Scotia and Glyko have entered into an
                  Acquisition  Agreement for a Plan of Arrangement  (the
                  "Acquisition Agreement") dated February 6, 2002.

         B.       The parties desire to amend certain terms of the Acquisition
                  Agreement as set forth herein.

         C.       Capitalized  terms used herein,  if not otherwise  defined,
                  shall have the meanings given to them in the Acquisition
                  Agreement.

     NOW,   THEREFORE,   in  consideration   of  the  covenants,   promises  and
representations set forth herein, and for other good and valuable consideration,
the receipt and sufficiency of which are hereby acknowledged,  the parties agree
that the Acquisition Agreement shall be amended as follows:

                                    AMENDMENT

         1.1      The reference to May 31, 2002 in Section 5.2(a) of the
Acquisition  Agreement shall be amended to refer to August 30, 2002 such that
Section 5.2(a) shall read as follows:

         "5.2     Meeting of Glyko Shareholders

                   (a)     Promptly after the date hereof, Glyko will take all
action pursuant to the requirements of the CBCA, the Interim Order, Canadian
Securities Legislation (and all other applicable securities laws), the TSE and
Glyko Charter Documents to convene the Glyko Shareholders Meeting to be held as
promptly as practicable, and in any event Glyko will use its commercially
reasonable efforts to convene such meeting not later than August 30, 2002 for
the purpose of voting upon the Continuance and the Arrangement. Glyko shall
ensure that the Glyko Shareholders Meeting is called, noticed, convened, held
and conducted, and that all proxies solicited in connection with the Glyko



Shareholders Meeting are solicited, in compliance with all applicable Legal
Requirements (including the Interim Order and Glyko Charter Documents). Glyko's
obligation to call, give notice of, convene and hold the Glyko Shareholders
Meeting in accordance with this Section 5.2(a) shall not be limited or otherwise
affected by the commencement, disclosure, announcement or submission of any
Superior Offer or other Acquisition Proposal. Subject to any withheld,
withdrawn, amended or modified recommendation of the Glyko Board of Directors in
accordance with Section 5.2(c), Glyko will use its commercially reasonable
efforts to solicit from its shareholders proxies in favor of the approval of the
Arrangement. Notwithstanding anything to the contrary contained in this
Agreement, Glyko may adjourn or postpone the Glyko Shareholders Meeting to the
extent necessary to ensure that any necessary supplement or amendment to the
Joint Proxy Circular is provided to Glyko's shareholders in advance of a vote on
the Continuance or the Arrangement or, if as of the time for which the Glyko
Shareholders Meeting is originally scheduled (as set forth in the Joint Proxy
Circular) there are insufficient Glyko Common Shares represented (either in
Person or by proxy) to constitute a quorum necessary to conduct the business of
the Glyko Shareholders Meeting."

         1.2      The reference to May 31, 2002 in Section 5.3 of the
Acquisition Agreement shall be amended to refer to August 30, 2002 such that
Section 5.3 shall read as follows:

          "5.3    Meeting of BioMarin Stockholders. Promptly after the date
hereof, BioMarin will take all action pursuant to the requirements of the
Delaware General Corporation Law, the United States 1933 Act, the United States
1934 Act (and all other applicable securities laws), Nasdaq, SWX Swiss Exchange
and BioMarin Charter Documents to convene the BioMarin Stockholders Meeting
to be held as promptly as practicable, and in any event BioMarin will use its
commercially reasonable efforts to convene such meeting not later than August
30, 2002 for the purpose of considering the approvalof the Arrangement
including, without limitation, the issuance of the BioMarin Common Stock in
connection with the Arrangement."

         1.3      The reference to June 15, 2002 in Section  8.1(b) of the
Acquisition Agreement shall be amended to refer to August 30, 2002 such that
Section 8.1(b) shall read as follows:

         "8.1     Termination

         ...

                  (b)      by either Glyko or BioMarin if the Arrangement shall
not have been consummated by August 30, 2002 for any reason; provided, however,
that the right to terminate this Agreement under this Section 8.1(b) shall not
be available to any party whose action or failure to act has been a principal
cause of or resulted in the failure of the  Arrangement to occur on or before
such date and such action or failure to act constitutes a breach of this
Agreement;"

         1.5      All terms and conditions of the Acquisition Agreement, as
amended as set forth herein, shall remain in full force and effect.



                              GENERAL PROVISIONS

         2.1      Counterparts. This Agreement may be executed in one or more
counterparts, all of which shall be considered one and the same agreement and
shall become effective when one or more counterparts have been signed by each of
the parties and delivered to the other party, it being understood that all
parties need not sign the same counterpart.

         2.2      Severability. In the event that any provision of this
Agreement, or the application thereof, becomes or is declared by a court of
competent jurisdiction to be illegal, void or unenforceable, the remainder of
this Agreement will continue in full force and effect and the application of
such provision to other Persons or circumstances will be interpreted so as
reasonably to effect the intent of the parties hereto. The parties further agree
to replace such void or unenforceable provision of this Agreement with a valid
and enforceable provision that will achieve, to the extent possible, the
economic, business and other purposes of such void or unenforceable provision.

         2.3      Governing Law. This Agreement shall be governed by, and
construed in accordance with, the laws of the state of Delaware, regardless of
the laws that might otherwise govern under applicable principles of conflicts of
laws thereof. In any action between the parties arising out of or relating to
this Agreement or any of the transactions contemplated by this Agreement:
(a) each of the parties irrevocably and unconditionally consents and submits to
the non-exclusive jurisdiction and venue of the state and federal courts located
in the state of California; (b) if any such action is commenced in a state
court, then, subject to applicable law, no party shall object to the removal of
such action to any federal court located in the Northern District of California;
(c); each of the parties hereby waives, and agrees not to assert in any such
action, any claim that it is not personally subject to the jurisdiction of such
court, that the action is brought in an inconvenient forum or that the venue of
the action is improper; and (d) each of the parties irrevocably consents to
service of process by first class certified mail, return receipt requested,
postage prepaid, to the address at which such party is to receive notice in
accordance with Section 9.2 of the Acquisition Agreement.

         2.4      Rules of Construction. The parties hereto agree that they have
been represented by counsel during the negotiation and execution of this
Agreement and, therefore, waive the application of any law, regulation, holding
or rule of construction providing that ambiguities in an agreement or other
document will be construed against the party drafting such agreement or
document.

         2.5      Assignment. This Agreement shall be binding upon, and shall be
enforceable by and inure solely to the benefit of, the parties hereto and their
respective successors and assigns; provided, however, that (i) neither this
Agreement nor any of Glyko's rights hereunder may be assigned by Glyko without
the prior written consent of BioMarin and (ii) neither this  Agreement nor any
of BioMarin's or BioMarin Nova Scotia's rights hereunder may be assigned by
BioMarin or BioMarin Nova Scotia without the prior written consent of Glyko
(other than an assignment to a direct or indirect wholly-owned Subsidiary of
BioMarin provided that such assignment shall not release BioMarin from liability
hereunder), and any attempted assignment of this Agreement or any of such rights
by Glyko or BioMarin and BioMarin Nova Scotia, as the case may be, without such
consent or except as provided for herein shall be void and of no effect.



         2.6      WAIVER OF JURY TRIAL. EACH OF BIOMARIN,  BIOMARIN NOVA SCOTIA
AND GLYKO HEREBY  IRREVOCABLY WAIVES ALL RIGHT TO TRIAL BY JURY IN ANY ACTION,
PROCEEDING OR COUNTERCLAIM  (WHETHER BASED ON CONTRACT,  TORT OR OTHERWISE)
ARISING OUT OF OR RELATING TO THIS AGREEMENT OR THE ACTIONS OF BIOMARIN,
BIOMARIN NOVA SCOTIA AND GLYKO IN THE NEGOTIATION,  ADMINISTRATION,  PERFORMANCE
AND ENFORCEMENT HEREOF.

         2.7      Attorneys'  Fees.  In any  action at law or suit in equity to
enforce this Agreement or the rights of any of the parties hereunder commenced
or initiated after the Effective  Date, the prevailing  party in such action or
suit shall be entitled to receive a reasonable sum for its attorneys' fees and
all other reasonable costs and expenses incurred in such action or suit.

     IN WITNESS  WHEREOF,  the parties  hereto have caused this  Agreement to be
executed  by their  duly  authorized  respective  officers  as of the date first
written above.

- ----------------------------------------------------- --------------------------
                                      BIOMARIN PHARMACEUTICAL INC.

                                      By:       /s/ Christopher M. Starr
                                                ------------------------
                                      Name:     Christopher M. Starr, Ph.D.

                                      Title:    Secretary


                                      BIOMARIN ACQUISITION (NOVA SCOTIA) COMPANY

                                      By:       /s/ Christopher M. Starr
                                                ------------------------
                                      Name:     Christopher M. Starr, Ph.D.

                                      Title:    President


                                      GLYKO BIOMEDICAL LTD.

                                      By:       /s/ Joerg Gruber
                                                ----------------
                                      Name:     Joerg Gruber

                                      Title:    Chairman