<PAGE>

                                                                  EXHIBIT 4.7(C)

     THE CONFIDENTIAL PORTIONS OF THIS EXHIBIT HAVE BEEN FILED SEPARATELY WITH
     THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO A CONFIDENTIAL TREATMENT
     REQUEST IN ACCORDANCE WITH RULE 24B-2 OF THE SECURITIES AND EXCHANGE ACT OF
     1934, AS AMENDED. REDACTED PORTIONS OF THIS EXHIBIT ARE MARKED BY AN ***.

                            SHARE PURCHASE AGREEMENT
              (FOR THE PURCHASE OF SHARES FROM MMV FINANCIAL INC.)

          THIS AGREEMENT is made as of the 18th day of November, 2005,

BETWEEN:

               MMV FINANCIAL INC., a corporation incorporated under the laws of
               Canada

               (the "VENDOR")

               - and -

               VERNALIS PLC, a corporation incorporated under the laws of
               England and Wales, with company number 2304992

               ("VERNALIS")

               - and -

               VERNALIS (CANADA) INC., a corporation incorporated under the laws
               of New Brunswick

               (the "PURCHASER")

RECITALS:

A.   Certain holders of warrants, conversion rights and options to acquire Class
     A Preference Shares, Class D Preference Shares and common shares (the
     "PRINCIPAL SHAREHOLDERS") in the capital of Cita Neuropharmaceuticals Inc.
     (the "CORPORATION"), the Purchaser, Vernalis and the Corporation have
     entered into a share purchase agreement (the "PRINCIPAL PURCHASE
     AGREEMENT") dated the date hereof whereby the Principal Shareholders have
     agreed to sell to the Purchaser all of their shares in the capital of the
     Corporation, including those issuable upon exercise of warrants, conversion
     rights, options and other rights to acquire shares in the capital of the
     Corporation, or to exchange certain options and other rights to acquire
     shares in the capital of the Corporation (both the shares and options
     being, collectively, the "PRINCIPAL SHAREHOLDERS' SECURITIES").

<PAGE>

B.   The Vendor wishes to sell all of its Class A Preference shares in the
     capital of the Corporation issuable upon exercise of warrants (the
     "PURCHASED SHARES") and the Purchaser wishes to purchase such shares, on
     and subject to the terms and conditions of this Agreement.

C.   The Vendor wishes to appoint VenGrowth to act as its representative with
     respect to certain matters with respect to this Agreement and related
     documents.

D.   The Purchaser is also entering into separate agreements with other holders
     of shares in the capital of the Corporation and holders of warrants,
     conversion rights, options or rights to acquire shares in the capital of
     the Corporation to acquire all such shares and/or rights.

          NOW THEREFORE in consideration of the mutual covenants and agreements
contained in this Agreement and other good and valuable consideration (the
receipt and sufficiency of which are hereby acknowledged), the parties hereto
agree as follows:

                                    ARTICLE 1
                                 INTERPRETATION

1.1  DEFINITIONS

          In this Agreement,

     1.1.1 "AFFILIATE" has the meaning attributed to such term under the
     Business Corporations Act (Ontario);

     1.1.2 "AGREED PAIN PROJECT BUDGET" means the budget for the Pain Project
     agreed between the Corporation and the Purchaser;

     1.1.3 "AGREED PARKINSON'S PROJECT BUDGET" means the budget for the
     Parkinson's Project agreed between the Corporation and the Purchaser;

     1.1.4 "AGREEMENT" means this agreement and all schedules attached to this
     agreement, in each case as they may be amended or supplemented from time to
     time, and the expressions "HEREOF", "HEREIN", "HERETO", "HEREUNDER",
     "HEREBY" and similar expressions refer to this agreement; and unless
     otherwise indicated, references to Articles and sections are to Articles
     and sections in this agreement;

     1.1.5 "ALZHEIMER'S PROJECT" means the Business which relates to CNP1061 for
     the indication of Alzheimer's disease;

     1.1.6 "API INVENTORY AMOUNT" means the aggregate purchase price of
     specified inventory acquired in respect of the Pain Project and the
     Parkinson's Project, as set out in the Principal Purchase Agreement;


                                      -2-

<PAGE>

     1.1.7 "BUSINESS" means the business of the Corporation of researching,
     developing and testing drug candidates related to the Pain Project, the
     Parkinson's Project and the Alzheimer's Project;

     1.1.8 "BUSINESS DAY" means any day, other than Saturday, Sunday or any
     statutory holiday in the Province of Ontario or London, England;

     1.1.9 "CANADIAN DOLLARS", "CDN. DOLLARS" or "CDN.$" means lawful currency
     of Canada;

     1.1.10 "CHARGE" means any security interest, lien, charge, pledge,
     encumbrance, mortgage, adverse claim or title retention agreement of any
     nature or kind;

     1.1.11 "CLASS 2 PREFERRED SHARES" means the Class 2 non-voting,
     retractable, redeemable, preferred shares, in registered form, of the
     Purchaser, having the share provisions set out in Schedule C and subject to
     the prior redemption right of the Class 1 non-voting, retractable,
     redeemable, preferred shares, in registered form, of the Purchaser, with a
     stated redemption price of U.S.$1.00 per share and with an aggregate
     Redemption Price as set out in the Final Proceeds Schedule, plus the
     aggregate Redemption Price of any additional Class 2 Preferred Shares
     issued in accordance with section 2.7.2 and to other Persons in respect of
     Net Cash, and subject to further reduction and set-off in accordance with
     section 2.4.7 and the share provisions attached to the Purchaser Shares;

     1.1.12 "CLASS 3 PREFERRED SHARES" means the Class 3 non-voting,
     retractable, redeemable, preferred shares, in registered form, of the
     Purchaser, having the share provisions set out in Schedule C and subject to
     the prior redemption right of the Class 1 non-voting, retractable,
     redeemable, preferred shares, in registered form, of the Purchaser and the
     Class 2 Preferred Shares, with a stated redemption price of U.S.$1.00 per
     share and with an aggregate Redemption Price as set out in the Final
     Proceeds Schedule, plus the aggregate Redemption Price of any additional
     Class 3 Preferred Shares issued in accordance with section 2.7.1 and to
     other Persons in respect of Net Cash, and subject to further reduction and
     set-off in accordance with section 2.4.7 and the share provisions attached
     to the Purchaser Shares;

     1.1.13 "CLASS 4 PREFERRED SHARES" means the Class 4 non-voting,
     retractable, redeemable, preferred shares, in registered form, of the
     Purchaser, having the share provisions set out in Schedule C and subject to
     the prior redemption right of the Class 1 non-voting, retractable,
     redeemable, preferred shares, in registered form, of the Purchaser and the
     Class 2 Preferred Shares, with a stated redemption price of U.S.$1.00 per
     share;

     1.1.14 "CLOSING" means the completion of the sale and purchase of the
     Purchased Shares pursuant to this Agreement at the Time of Closing;

     1.1.15 "CLOSING DATE" means such date for completion of the purchase of the
     Principal Shareholders' Securities pursuant to the Principal Purchase
     Agreement as determined pursuant to the Principal Purchase Agreement;


                                      -3-

<PAGE>

     1.1.16 "CONVERSION RATE" means, in relation to the conversion of one
     Currency to another on a particular day, the rate of exchange quoted by the
     Bank of Canada as its spot rate of exchange for the conversion of the one
     Currency to the other at approximately noon (Toronto time) on such day;

     1.1.17 "CREST" means the relevant system, as defined in the UK
     Uncertificated Securities Regulations 1995 (SI 1995 No. 93/3272), as
     amended (in respect of which CRESTCo Limited is operator);

     1.1.18 "CURRENCY" means Canadian Dollars, Pounds Sterling or United States
     Dollars;

     1.1.19 "ESTIMATED SIGNING BALANCE SHEET" means the consolidated balance
     sheet of the Corporation and the Subsidiaries as at the date of this
     Agreement, and the calculation of Vernalis Liabilities, prepared pursuant
     to the Principal Purchase Agreement;

     1.1.20 "FDA" means the Food and Drug Administration of the United States of
     America;

     1.1.21 "FINAL CLOSING BALANCE SHEET" means the consolidated balance sheet
     of the Corporation and the Subsidiaries, as at the Closing Date, and the
     calculation of the Net Cash as at the Closing Date, prepared pursuant to
     the Principal Purchase Agreement;

     1.1.22 "FINAL PROCEEDS SCHEDULE" means the schedule setting out, as at the
     Closing Date, the allocation of the Initial Consideration, MMV Non-Vendor
     Placing Shares, Purchaser Shares, each class of shares in the capital of
     the Purchaser, options to acquire such shares, Redemption Amounts based on
     the occurrence of Milestones and the other amounts set forth therein (prior
     to reduction and set-off in accordance with section 2.4.7 and excluding the
     allocation of the Redemption Amounts in respect of any additional Class 2
     Preferred Shares, Class 3 Preferred Shares and Class 4 Preferred Shares,
     issued pursuant to section 2.7 or to other Persons in respect of Net Cash),
     a pro forma of which is set out in Schedule A (the "PRO FORMA PROCEEDS
     SCHEDULE"), such schedule in final form to be agreed between Vernalis and
     the Corporation pursuant to the Principal Purchase Agreement;

     1.1.23 "FINAL SIGNING BALANCE SHEET" means the consolidated balance sheet
     of the Corporation and the Subsidiaries as at the date of this Agreement,
     and the calculation of Vernalis Liabilities, prepared pursuant to the
     Principal Purchase Agreement;

     1.1.24 "FROVATRIPTAN ANNOUNCEMENT" means the announcement by Vernalis of
     the results of the pivotal efficacy study for its Frovatriptan MRM
     prophylaxis development programme;

     1.1.25 "INITIAL CONSIDERATION" means, subject to the provisions of this
     Agreement, the allotment and issue of the MMV Non-Vendor Placing Shares to
     the Vendor as set out in the Final Proceeds Schedule;


                                      -4-

<PAGE>

     1.1.26 "INTERIM EXPENDITURE" means such portion of the Interim Funding
     Amount advanced by the Purchaser or Vernalis to the Corporation where the
     proposed use of such funds indicated by the Corporation pursuant to the
     Principal Purchase Agreement was to fund Permitted Costs;

     1.1.27 "INTERIM FUNDING AMOUNT" means the aggregate amount advanced by the
     Purchaser or Vernalis to the Corporation pursuant to the Principal Purchase
     Agreement to fund the Corporation's operations;

     1.1.28 "MILESTONE", in respect of the Purchaser Shares, has the meaning
     attributed to such term in section 2.4.2;

     1.1.29 "MILESTONE CONSIDERATION" means the issue of Purchaser Shares to the
     Vendor as set out in the Final Proceeds Schedule and in accordance with
     section 2.4.1;

     1.1.30 "MILESTONE SHARE PRICE" means, in respect of any Vernalis Shares to
     be issued on a Redemption Date, the average of the closing middle market
     prices of a Vernalis Share as shown in the Daily Official List of the
     London Stock Exchange plc on the 30 trading days up to and including the
     trading day (the "FINAL TRADING DAY") immediately prior to the occurrence
     of the relevant Milestone and converted to the relevant Currency at the
     Conversion Rate on the Final Trading Day;

     1.1.31 "MILESTONE SHARES" means, in respect of any Redemption Amount, such
     number of Vernalis Shares, if any, to be allotted and issued to satisfy
     such Redemption Amount in accordance with section 2.4.5;

     1.1.32 "MMV LOAN" means the loan made by the Vendor to the Corporation
     pursuant to the credit agreement between the Corporation and the Vendor
     dated February 25, 2005 which, as at the date hereof, is in the principal
     amount of U.S.$2,053,401  (subject to further repayment of principal after
     the date hereof);

     1.1.33 "MMV NON-VENDOR PLACING SHARES" means Vernalis Shares to be allotted
     and issued to the Vendor in accordance with section 2.3.1 in the number set
     out in the Final Proceeds Schedule;

     1.1.34 "NET CASH" means an amount equal to:

          (i)  the aggregate amount of cash, receivables, and deposits (but not
               prepaid expenses) of the Corporation and the Subsidiaries as at
               the Closing Date plus the API Inventory Amount,

          less

          (ii) the aggregate amount of all liabilities, including any
               liabilities arising in connection with the entering into of this
               Agreement, the completion of the transactions contemplated
               hereby, any withholding tax remittances, interest and penalties
               remaining unpaid in respect of payments to Chiesi Farmaceutici
               S.p.A. pursuant to the Chiesi Licence Agreements (as defined in
               the Principal Purchase Agreement) (other than U.S.$ *** to be
               withheld in connection with its right to acquire Class C
               Preference shares


                                      -5-

<PAGE>

               in the capital of the Corporation), of the Corporation and the
               Subsidiaries as at the Closing Date,

          plus

          (iii) the Vernalis Liabilities less such portion of the Interim
               Funding Amount advanced by the Purchaser or Vernalis to the
               Corporation where the proposed use of such funds indicated by the
               Corporation pursuant to the Principal Purchase Agreement was to
               fund Vernalis Liabilities,

          to be set out in the Final Closing Balance Sheet and calculated in the
          manner provided in Schedule 1.1.34;

     1.1.35 "PAIN PROJECT" means the Business which relates to CNP3381 for the
     indication of diabetic neuropathic pain;

     1.1.36 "PARKINSON'S PROJECT" means the Business which relates to CNP1512
     for the indication of Parkinson's disease;

     1.1.37 "PERMITTED COSTS" means any expenditure or commitment incurred or
     committed to by the Corporation and the Subsidiaries in accordance with the
     Agreed Pain Project Budget or the Agreed Parkinson's Project Budget, or to
     pay salaries of employees of the Corporation and overhead costs at the same
     level as at the date of this Agreement, and approved pursuant to the
     Principal Purchase Agreement;

     1.1.38 "PERSON" means any individual, partnership, limited partnership,
     joint venture, syndicate, sole proprietorship, company or corporation with
     or without share capital, unincorporated association, trust, trustee,
     executor, administrator or other legal personal representative, regulatory
     body or agency, government or governmental agency, authority or entity
     however designated or constituted;

     1.1.39 "POUNDS STERLING" or "L" means lawful currency of the United
     Kingdom;

     1.1.40 "PRIME RATE" means the annual rate of interest which the Royal Bank
     of Canada establishes at its principal office in Toronto as the reference
     rate of interest to determine interest rates it will charge at such time
     for demand loans in Canadian dollars made to its customers in Canada and
     which it refers to as its "prime rate of interest";

     1.1.41 "PRO FORMA PROCEEDS SCHEDULE" has the meaning attributed to such
     term in section 1.1.22;

     1.1.42 "PURCHASE PRICE" has the meaning attributed to such term in section
     2.2;

     1.1.43 "PURCHASER SHAREHOLDERS AGREEMENT" means the unanimous shareholders
     agreement to be entered into pursuant to the Business Corporations Act (New
     Brunswick) among all of the shareholders of the Purchaser, the Purchaser
     and Vernalis, substantially in the form attached as Schedule B;

     1.1.44 "PURCHASER SHARES" means, collectively, the Class 2 Preferred Shares
     to be issued to the Vendor and to the Principal Shareholders and the Class
     3 Preferred


                                      -6-

<PAGE>

     Shares to be issued to the Vendor, the Principal Shareholders and other
     holders of the common shares and rights to acquire common shares in the
     capital of the Corporation, all with share rights, privileges, restrictions
     and conditions set out in the share provisions substantially in the form
     attached as Schedule C;

     1.1.45 "REDEMPTION AMOUNT" means, in respect of any Redemption Date, the
     aggregate Redemption Price payable in cash and/or Vernalis Shares owing to
     the Vendor by the Purchaser upon the retraction or redemption of its
     Purchaser Shares in accordance with the share provisions to the Purchaser
     Shares, or by Vernalis (or its designee or assignee) upon exercise of its
     call right in accordance with section 2.4.4, and, subject in either case,
     to reduction or set-off of the Vendor's entitlement thereto in accordance
     with section 2.4.7 and the share provisions attached to the Purchaser
     Shares;

     1.1.46 "REDEMPTION DATE" means (i) in respect of any Milestone, the 45th
     day after the occurrence of that Milestone, or such other date as may be
     agreed between the Purchaser and the Vendor' Representative, and (ii) the
     Special Redemption Date;

     1.1.47 "REDEMPTION PRICE" means the stated redemption price of each
     Purchaser Share in respect of a Redemption Date of U.S.$ *** each;

     1.1.48 "REPORT" means the customary final report produced for filing with
     the FDA;

     1.1.49 "SPECIAL REDEMPTION DATE" has the meaning attributed to such term in
     section 2.7;

     1.1.50 "SUBSIDIARIES" means 2037137 Ontario Inc. and 2060347 Ontario Inc.,
     each incorporated under the laws of the Province of Ontario and each a
     wholly-owned subsidiary of the Corporation;

     1.1.51 "TIME OF CLOSING" means such time for completion of the purchase of
     the Principal Shareholders' Securities pursuant to the Principal Purchase
     Agreement on the Closing Date;

     1.1.52 "UNITED STATES DOLLARS", "U.S. DOLLARS" or "U.S.$" means lawful
     currency of the United States of America;

     1.1.53 "VENDORS' REPRESENTATIVE" has the meaning attributed to such term in
     section 2.5;

     1.1.54 "VENDORS' REPRESENTATIVE AGREEMENT" has the meaning attributed to
     such term in section 2.5;

     1.1.55 "VERNALIS LIABILITIES" means the aggregate liabilities as at the
     date of this Agreement incurred or committed to by the Corporation and the
     Subsidiaries in respect of the Pain Project and the Parkinson's Project
     which are not outstanding for more than 60 days past their invoice date and
     appended to the Estimated Signing


                                      -7-

<PAGE>

     Balance Sheet, subject to adjustment in accordance with the Final Signing
     Balance Sheet; and

     1.1.56 "VERNALIS SHARES" means the ordinary shares of L0.05 each in the
     capital of Vernalis, adjusted for any stock split or consolidation effected
     after the date of this Agreement.

1.2  HEADINGS

          The inclusion of headings in this Agreement is for convenience of
reference only and shall not affect the construction or interpretation hereof.

1.3  GENDER AND NUMBER

          In this Agreement, unless the context otherwise requires, words
importing the singular include the plural and vice versa, words importing gender
include all genders or the neuter, and words importing the neuter include all
genders.

1.4  CURRENCY CONVERSION AND INDEMNITY

          If, in connection with any action or proceeding brought in connection
with this Agreement or any judgment or order obtained as a result thereof, it
becomes necessary to convert any amount due hereunder in one Currency (the
"OTHER CURRENCY") into Canadian Dollars, then the conversion shall be made at
the Conversion Rate on the first Business Day prior to the day on which payment
is received.

          If the conversion is not able to be made in the manner contemplated by
the preceding paragraph in the jurisdiction in which the action or proceeding is
brought, then the conversion shall be made at the Conversion Rate on the date
fixed by the court for such conversion.

          If the Conversion Rate on the date of payment is different from the
Conversion Rate on such first Business Day or on the date fixed for conversion
by the court, as the case may be, the party liable to make the payment (the
"PAYOR") shall pay such additional amount (if any) in Canadian Dollars as may be
necessary to ensure that the amount paid on such payment date is the aggregate
amount in Canadian Dollars which, when converted at the Conversion Rate on the
date of payment, is the amount due in the Other Currency, together with all
costs, charges and expenses of conversion. Any additional amount owing by the
payor to the party or parties entitled to payment thereof pursuant to the
provisions of this section 1.4 shall be due as a separate debt and shall give
rise to a separate cause of action and shall not be affected by or merge into
any judgment obtained for any other amounts due under or in respect of this
Agreement.

1.5  ENTIRE AGREEMENT

          This Agreement constitutes the entire agreement between the parties
pertaining to the purchase of the common shares in the capital of the
Corporation. This Agreement supersedes all prior arrangements and
understandings, whether written or oral, relating to such subject


                                      -8-

<PAGE>

matter in any way. There are no warranties, conditions, or representations
(including any that may be implied by statute) and there are no agreements in
connection with such subject matter except as specifically set forth or referred
to in this Agreement. No reliance is placed on any warranty, representation,
opinion, advice or assertion of fact made either prior to, contemporaneous with,
or after entering into this Agreement, or any amendment or supplement thereto,
by any party to this Agreement or its directors, officers, employees or agents,
to any other party to this Agreement or its directors, officers, employees or
agents, except to the extent that the same has been reduced to writing and
included as a term of this Agreement, and none of the parties to this Agreement
has been induced to enter into this Agreement or any amendment or supplement by
reason of any such warranty, representation, opinion, advice or assertion of
fact. Accordingly, there shall be no liability, either in tort or in contract,
assessed in relation to any such warranty, representation, opinion, advice or
assertion of fact, except to the extent contemplated above. To the extent that
there is any inconsistency between the share provisions attached to the
Purchaser Shares and the terms of this Agreement, the terms of this Agreement
shall prevail.

1.6  WAIVER, AMENDMENT

          Except as expressly provided in this Agreement, no amendment or waiver
of this Agreement shall be binding unless executed in writing by the party to be
bound thereby. No waiver of any provision of this Agreement shall constitute a
waiver of any other provision nor shall any waiver of any provision of this
Agreement constitute a continuing waiver unless otherwise expressly provided.

1.7  GOVERNING LAW

          This Agreement shall be governed by and construed in accordance with
the laws of the Province of Ontario and the laws of Canada applicable therein.

1.8  ATTORNMENT

          The Vendor, Vernalis, and the Purchaser (collectively, the "ATTORNING
PARTIES" and, individually, an "ATTORNING PARTY") each agrees that any suit,
action or proceeding arising out of or relating to this Agreement against an
attorning party or any of an attorning party's assets may be brought in any
court in the Province of Ontario, and the attorning parties hereby irrevocably
and unconditionally attorn and submit to the jurisdiction of such courts. The
attorning parties irrevocably waive and agree not to raise any objection any of
them might now or hereafter have to the bringing of any such suit, action or
proceeding in any such court including, without limitation, any objection that
the place where such court is located is an inconvenient forum or that there is
any other suit, action or proceeding in any other place relating in whole or in
part to the same subject matter. Each attorning party agrees that any judgment
or order against that attorning party in any such suit, action or proceeding
brought in such a court shall be conclusive and binding upon that attorning
party and consents to any such judgment or order being recognized and enforced
in the courts of its jurisdiction of incorporation.


                                      -9-

<PAGE>

                                    ARTICLE 2
                                PURCHASE AND SALE

2.1  AGREEMENT TO PURCHASE AND SELL

          Simultaneously with the completion of the purchase or exchange from
the Principal Shareholders of the Principal Shareholders' Securities pursuant to
the Principal Purchase Agreement and subject to the terms of this Agreement, at
the Time of Closing the Vendor shall sell and the Purchaser shall purchase all
of the Purchased Shares for Initial Consideration and Milestone Consideration as
set forth opposite the Vendor's name in the Final Proceeds Schedule. The
Purchaser shall not be obligated to purchase or exchange any of the Purchased
Securities in accordance with this Agreement unless the purchase or exchange of
all of the Principal Shareholders' Securities is completed simultaneously in
accordance with the Principal Purchase Agreement.

2.2  PURCHASE PRICE

          The aggregate purchase price (the "PURCHASE PRICE") to be paid by the
Purchaser to the Vendor for the Purchased Shares shall be equal to the aggregate
of the Initial Consideration and the Milestone Consideration, subject to
adjustment on the Special Redemption Date in accordance with section 2.7.1.

2.3  SATISFACTION OF THE INITIAL CONSIDERATION

     2.3.1 The Initial Consideration shall be satisfied at the Time of Closing
     by the allotment and issue of the MMV Non-Vendor Placing Shares, credited
     as paid in full, and delivered by Vernalis to the Vendor (or its nominee)
     as set out in the Final Proceeds Schedule in uncertificated form to an
     account in CREST designated by the Vendor.

     2.3.2 The Purchaser shall cause Vernalis to deliver the MMV Non-Vendor
     Placing Shares to the Vendor in accordance with section 2.3.1.

2.4  SATISFACTION OF MILESTONE CONSIDERATION

     2.4.1 The Milestone Consideration shall be satisfied at the Time of Closing
     by the issue of such number of Purchaser Shares as is set out opposite the
     Vendor's name in the Final Proceeds Schedule, credited as paid in full, and
     delivered by the Purchaser to the Vendor in certificated form. The
     Purchaser Shares shall be redeemed by the Purchaser (and delivered by the
     Vendor to the Purchaser for redemption) on each Redemption Date for the
     applicable Redemption Amount in accordance with the share provisions
     attached to the Purchaser Shares and the provisions of this Agreement or,
     if Vernalis exercises its call right in accordance with section 2.4.4,
     purchased by Vernalis (and delivered by the Vendor to Vernalis for
     purchase) on such Redemption Date for the applicable Redemption Amount in
     accordance with the share provisions attached to the Purchaser Shares and
     the provisions of this Agreement. Each of the Vendor, the Purchaser and
     Vernalis agrees to be bound by the share provisions attached to the
     Purchaser Shares, subject to the terms of this Agreement.


                                      -10-

<PAGE>

     2.4.2 The occurrence of each of the following events (each a "MILESTONE")
     shall give rise to a retraction, redemption or call right in respect of the
     Purchased Shares up to the amounts specified below (each a "MILESTONE
     PAYMENT"), in accordance with the share provisions attached to the
     Purchaser Shares and the provisions of this Agreement, and Vernalis shall
     notify the Vendors' Representative of the occurrence of each Milestone
     within 10 Business Days of its occurrence and shall indicate the Redemption
     Date with respect to such Milestone:

          2.4.2.1 in respect of the Pain Project:

               2.4.2.1.1 U.S.$ 5,833,334, upon the completion of a report by
               Vernalis or its affiliates to be produced in a timely manner
               following completion of a clinical study which generates data
               sufficient to support the requirements of 21 CFR 312.21(b)
               sufficient to justify Vernalis progressing with a Phase IIb or a
               Phase III study programme, as the case may be;

               2.4.2.1.2 U.S.$ 5,833,333, upon the completion of a Report by
               Vernalis or its affiliates to be provided in a timely manner
               following completion of a clinical study which generates data
               sufficient to support the requirements of 21 CFR 312.21(c) for a
               submission for regulatory approval to the FDA to market and sell
               in the USA a product comprising CNP3381 for the treatment of
               diabetic neuropathic pain; and

               2.4.2.1.3 U.S.$ 5,833,333, upon the issuance by the FDA of a
               written notification to Vernalis or its affiliates pursuant to 21
               CFR 314.105(a) that the FDA approves CNP3381 for the treatment of
               diabetic neuropathic pain, Alzheimer's disease, post-operative
               pain or mixed pain related to palliative care. For greater
               certainty, if CNP3381 is developed for more than one of the
               above-noted indications, only the first FDA approval for one of
               the indications noted above shall be a Milestone. If the
               Milestone referred to in section 2.4.2.1.2 has not occurred prior
               to the FDA approval contemplated by this section 2.4.2.1.3, that
               Milestone shall be deemed to occur concurrently with the
               occurrence of the Milestone contemplated in this section
               2.4.2.1.3; and

          2.4.2.2 in respect of the Parkinson's Project:

               2.4.2.2.1 U.S.$ 5,833,334, upon the enrollment by Vernalis or its
               affiliates of the first patient into a Phase III study for the
               purpose of generating data to support the requirements of 21 CFR
               312.21(b);

               2.4.2.2.2 U.S.$ 5,833,333, upon the completion of a Report by
               Vernalis or its affiliates to be produced in a timely manner
               following completion of a trial which generates data sufficient
               to support the requirements of 21 CFR 312.21(c) for a submission
               for regulatory approval to the FDA to market and sell in the USA
               a product comprising CNP1512 for the treatment of Parkinson's
               disease; and


                                      -11-

<PAGE>
               2.4.2.2.3 U.S.$ 5,833,333, upon the issuance by the FDA of a
               written notification to Vernalis or its affiliates pursuant to 21
               CFR 314.105(a) that the FDA approves CNP1512 for the treatment of
               Parkinson's disease,

     provided that the Milestone Payment in respect of each of the first two
     Milestones to occur shall be reduced by an amount equal to one-half of the
     amount of the Interim Expenditure.

     2.4.3 Subject to section 2.4.4, the Redemption Amount in respect of a
     Redemption Date shall be satisfied by the allotment and issue of Vernalis
     Shares or, at the option of the Purchaser, by payment in cash or by a
     combination of cash and Vernalis Shares (such combination of cash and
     Vernalis Shares to be at the discretion of the Purchaser) on that
     Redemption Date. Notwithstanding the foregoing, the Redemption Amount in
     respect of the Special Redemption Date, if applicable, may only be
     satisfied in cash.

     2.4.4 Vernalis (or its designee or assignee) may, at its option, elect, by
     notice to the Vendors' Representative at any time (i) on or before the
     Special Redemption Date and (ii) after the occurrence of a Milestone and on
     or before the relevant Redemption Date, to purchase, on the relevant
     Redemption Date, such Purchaser Shares which may be redeemed on such
     Redemption Date for the applicable Redemption Amount, notwithstanding that
     the Vendor or the Purchaser has exercised its retraction or redemption
     right, respectively, pursuant to the share provisions attached to the
     Purchaser Shares. If Vernalis exercises its call right in accordance with
     this section 2.4.4 and the shares attached to the Purchaser Shares in
     respect of a Redemption Date, the Redemption Amount payable on that
     Redemption Date shall be satisfied by the allotment and issue of Vernalis
     Shares or, at the option of Vernalis, by payment in cash or by a
     combination of cash and Vernalis Shares (such combination of cash and
     Vernalis Shares to be at the discretion of Vernalis) on that Redemption
     Date and in accordance with the share provisions attached to the Purchaser
     Shares. Upon exercise by Vernalis of its call right in accordance with this
     section 2.4.4, the retraction and redemption right of the Vendor or the
     Purchaser pursuant to the share provisions attached to the Purchaser Shares
     in respect of the Redemption Date shall be cancelled. Notwithstanding the
     foregoing, the Redemption Amount in respect of the Special Redemption Date,
     if applicable, may only be satisfied in cash.

     2.4.5 To the extent the Purchaser or Vernalis, as applicable, elects not to
     satisfy any Redemption Amount in cash, Vernalis shall allot and issue
     Vernalis Shares, credited as paid in full, and deliver on the relevant
     Redemption Date to the Vendor (or its nominee), in uncertificated form to
     an account in CREST designated by the Vendor, such number of Vernalis
     Shares as at the Milestone Share Price shall be equal to the Vendor's
     entitlement to a Redemption Amount divided by the Milestone Share Price
     (rounded up to the nearest whole share), subject to any further reduction
     as provided in section 2.4.7.

     2.4.6 Any Redemption Amount to be satisfied in cash, subject to any further
     reduction as provided in section 2.4.7, shall be paid on the relevant
     Redemption Date to the Vendors' Representative, on behalf of the Vendor,
     and the Vendors'


                                      -12-

<PAGE>

     Representative shall pay such Redemption Amount to the Vendor in accordance
     with its entitlement on the Redemption Date and neither the Purchaser nor
     Vernalis, as applicable, shall have any responsibility for such
     distribution. The Vendors' Representative may, not less than five Business
     Days prior to the relevant Redemption Date, direct the Purchaser or
     Vernalis, as applicable, to pay to the Vendor directly any amounts
     contemplated by this section 2.4.6.

     2.4.7 The Vendor's entitlement to a Redemption Amount on a Redemption Date
     may be further reduced and set-off by the Purchaser or Vernalis by and
     against the amount of any claim against the Vendor in respect of any loss,
     damages or deficiencies suffered by the Purchaser or Vernalis as a result
     of any breach by the Vendor of a representation or covenant contained in
     this Agreement, being either the approximate and reasonable estimate of the
     likely amount of any such claim as determined by the Purchaser or Vernalis,
     as applicable, or, if such claim has been settled or finally determined,
     the amount of such claim, to the extent not satisfied in full on the fifth
     Business Day preceding the Redemption Date (using the Milestone Share Price
     as the value of the Milestone Shares when calculating the number of
     Milestone Shares to be reduced).

     2.4.8 In the event the Vendor's entitlement to a Redemption Amount is
     reduced by the amount of an estimated claim (the "ESTIMATED CLAIM") as
     provided in section 2.4.7, upon such claim becoming settled or finally
     determined (the "DETERMINED CLAIM"), the Purchaser or Vernalis, as
     applicable, shall, if and to the extent the amount of the Determined Claim
     for which the Vendor is responsible is less than the Estimated Claim for
     which the Vendor is responsible, satisfy the difference (up to the amount
     of the reduction made pursuant to section 2.4.7) in cash or Vernalis Shares
     or a combination of the two (depending upon and proportionately to whether
     the relevant Redemption Amount was satisfied in cash or Vernalis Shares or
     a combination of the two) and the provisions of this section 2.4 shall
     apply mutatis mutandis, with the Milestone Share Price, when calculating
     the number of Vernalis Shares to be issued pursuant to this section 2.4.8,
     being that used in respect of the relevant Redemption Date.

     2.4.9 Notwithstanding that the Purchaser or Vernalis, as applicable, elects
     to pay a Redemption Amount, in whole or in part, in Vernalis Shares, the
     Purchaser or Vernalis, as applicable, may elect to pay to any Vendor who is
     located or resident in a jurisdiction on the Redemption Date, or date for
     payment pursuant to section 2.4.8, where the issuance of such shares would
     be in contravention of applicable securities laws (with no obligation to
     qualify or register the shares or rely upon an exemption from such
     requirement), its entitlement to a Redemption Amount in cash only.

     2.4.10 In the event that the Vendor is a non-resident of Canada under the
     Income Tax Act (Canada) on any Redemption Date, or date for payment
     pursuant to section 2.4.8, it shall deliver to the Purchaser or Vernalis,
     as applicable, a certificate issued pursuant to section 116 of the Income
     Tax Act (Canada) on account of that Vendor's entitlement to a Redemption
     Amount on such Redemption Date, or date for payment pursuant to section
     2.4.8. Notwithstanding the foregoing, neither the Purchaser nor


                                      -13-

<PAGE>

     Vernalis, as applicable, shall be required to issue any Purchaser Shares or
     Vernalis Shares to the Vendor until the delivery of such certificate, as
     applicable. The Purchaser or Vernalis, as applicable, shall be entitled to
     deduct or withhold from any Redemption Amount payable to a Vendor any
     amount required to be deducted or withheld under applicable law.

     2.4.11 Vernalis (or its designee or assignee) may, at its option, elect by
     notice to the Vendors' Representative at any time after the earlier of (i)
     the tenth anniversary of the Time of Closing or (ii) the Redemption Date in
     respect of the last Milestone to occur, provided that any Redemption Amount
     owing in respect of such Redemption Date has been satisfied in full, to
     purchase, on the date specified in such notice, all of the outstanding
     Purchaser Shares for a purchase price of U.S.$ *** per share, payable in
     cash to the Vendors' Representative on behalf of the Vendor.

2.5  APPOINTMENT OF VENDORS' REPRESENTATIVE

          The Vendor hereby appoints The VenGrowth Advanced Life Sciences Fund
Inc. to act as its representative (the "VENDORS' REPRESENTATIVE") to carry out
such duties and responsibilities and to exercise such rights and powers on its
behalf as are provided in this Agreement and in related documents in accordance
with an agreement (the "VENDORS' REPRESENTATIVE AGREEMENT") to be entered into
among the Vendors' Representative, the Vendor, and certain other Persons to
become shareholders or optionholders of the Purchaser.

          In the event of any disagreement between the Vendor and/or the
Vendors' Representative resulting in adverse claims or demands with respect to
the amounts delivered under this Agreement to the Vendors' Representative on
behalf of the Vendor, the Vendors' Representative shall be entitled, at its
option, to refuse to comply with any claims or demands on it with respect
thereto so long as such disagreement shall continue, and in so refusing, the
Vendors' Representative may elect to make no delivery of such amounts. In doing
so, the Vendors' Representative shall not be or become liable in any way to the
Vendor, Vernalis or the Purchaser for its failure or refusal to comply with such
claims or demands.

          The Vendors' Representative may resign from such position at any time
by written notice to the parties to the Vendors' Representative Agreement, the
Purchaser and Vernalis provided that the Vendors' Representative shall have
appointed a successor to the Vendors' Representative satisfactory to the
Purchaser, acting reasonably, which appointment will be binding on the parties
to the Vendors' Representative Agreement, and provided that such successor shall
have consented to act in such capacity.

2.6  DELIVERY OF SHARE CERTIFICATES

          At the Time of Closing, the Vendor shall deliver to the Purchaser
share certificates representing the Purchased Shares duly endorsed in blank for
transfer or accompanied by duly signed powers of attorney for transfer in blank.


                                      -14-

<PAGE>

2.7  NET CASH PAYMENT

          On the 15th Business Day after the final determination of the Final
Closing Balance Sheet in accordance with the Principal Purchase Agreement:

     2.7.1 if the Net Cash as set out in the Final Closing Balance Sheet is a
     positive number, the Purchaser shall issue to the Vendor on such date (the
     "SPECIAL REDEMPTION DATE") such number of Class 3 Preferred Shares (rounded
     upwards to the nearest whole share) with an aggregate Redemption Price
     equal to the amount of such Net Cash, converted to U.S. Dollars at the
     Conversion Rate as at the Closing Date, multiplied by a fraction, (i) the
     numerator of which is the number of Class 3 Preferred Shares owned by the
     Vendor on the Special Redemption Date and (ii) the denominator of which is
     the aggregate of the number of all Class 3 Preferred Shares outstanding on
     the Special Redemption Date and the number of all Class 4 Preferred Shares
     issuable upon exercise of all options outstanding on the Special Redemption
     Date. Such Class 3 Preferred Shares issuable to the Vendor shall be
     credited as paid in full, and delivered by the Purchaser to the Vendors'
     Representative, on behalf of the Vendor, in certificated form; and

     2.7.2 if the Net Cash as set out in the Final Closing Balance Sheet is a
     negative number, the Vendor shall be deemed to subscribe on the Special
     Redemption Date at U.S. $ *** per share for such number of Class 2
     Preferred Shares (rounded upwards to the nearest whole share) with an
     aggregate Redemption Price equal to the amount of such Net Cash (expressed
     as a positive number), together with interest calculated thereon at the
     Prime Rate from and including the date of Closing to but excluding the date
     of payment, converted to U.S. Dollars at the Conversion Rate as at the
     Closing Date, multiplied by a fraction, (i) the numerator of which is the
     aggregate Redemption Price of Class 2 Preferred Shares owned by the Vendor
     on the Special Redemption Date, and (ii) the denominator of which is the
     aggregate Redemption Price of all Class 2 Preferred Shares outstanding on
     the Special Redemption Date, and the aggregate subscription price shall be
     paid by the Vendors' Representative, on behalf of the Vendor, to the
     Purchaser. Subject to payment in full of the aggregate subscription price
     by the Vendors' Representative, such Class 2 Preferred Shares, issuable to
     the Vendor, shall be credited as paid in full, and delivered by the
     Purchaser to the Vendors' Representative, on behalf of the Vendor, in
     certificated form. The Vendor shall reimburse the Vendors' Representative
     for such amount.

2.8  FINAL PROCEEDS SCHEDULE

          The Final Proceeds Schedule shall be based on the Pro Forma Proceeds
Schedule and calculated in accordance with, and in a manner consistent with, the
spreadsheet contained within the CD-Rom delivered by the Corporation to Vernalis
on the date of this Agreement, updated to reflect the final resolution as at the
Closing Date of the variable factors noted in the Pro Forma Proceeds Schedule
(other than those variables to be reflected in the Final Closing Balance Sheet).
The Final Proceeds Schedule as agreed between Vernalis and the Corporation shall
be binding upon the parties to this Agreement, and neither the Purchaser nor
Vernalis shall have any responsibility or liability for any dispute or claim
arising as to the allocation, in


                                      -15-

<PAGE>

accordance with the Final Proceeds Schedule, of Purchaser Shares, each class of
shares in the capital of the Purchaser, options to acquire such shares,
Redemption Amounts and the other amounts set forth therein. The Vendors
acknowledge and agree that the Pro Forma Proceeds Schedule and the Final
Proceeds Schedule are intended only to set out the allocation of Purchaser
Shares, each class of shares in the capital of the Purchaser, options to acquire
such shares, Redemption Amounts and the other amounts set forth therein (prior
to reduction and set-off in accordance with section 2.4.7 and excluding the
issue of any additional Class 2 Preferred Shares, Class 3 Preferred Shares and
any Class 4 Preferred Shares pursuant to section 2.7 or to other Persons in
respect of Net Cash) and, subject to section 2.7, nothing in this section 2.8
shall oblige the Purchaser or Vernalis to pay, issue or allot (or procure the
payment, issue or allotment of) additional consideration to the Vendors. In the
event that additional Class 2 Preferred Shares, Class 3 Preferred Shares or
Class 4 Preferred Shares are issued in accordance with section 2.7 or to other
Persons in respect of Net Cash, the Final Proceeds Schedule shall be updated by
the Purchaser and the Vendors' Representative accordingly.

2.9  RESALE RESTRICTIONS ON MMV NON-VENDOR PLACING SHARES

          The MMV Non-Vendor Placing Shares allotted and issued to the Vendor
shall be entitled to be sold in accordance with applicable securities law
requirements, provided however in order to ensure the maintenance of an orderly
market in Vernalis Shares after the Time of Closing, the Vendor issued and
allotted in excess of 500,000 MMV Non-Vendor Placing Shares covenants not to
dispose of those shares on or before the Frovatriptan Announcement except:

     2.9.1 with the prior approval of Vernalis (such approval not to be
     unreasonably withheld) and provided that such sale takes place through
     Vernalis' designated brokers in London and that such brokers are able to
     sell such shares on commercially reasonable terms and in accordance with
     applicable regulatory requirements;

     2.9.2 a sale of less than *** MMV Non-Vendor Placing Shares in any given
     five day trading period by the Vendor;

     2.9.3 a disposal pursuant to a court order or in acceptance of an offer by
     Vernalis to buy back its own shares; or

     2.9.4 to accept a general offer made for all of the outstanding Vernalis
     Shares (other than Vernalis Shares held by the offeror and/or Persons
     acting in concert with the offeror), or to execute an irrevocable
     commitment to accept such a general offer, or a disposal or agreement to
     dispose of shares to a Person who has made or announced his intention to
     make, or has a bona fide intention to make, such an offer.

          In the event that the Frovatriptan Announcement does not occur on or
before June 30, 2006, the Vendor shall be free to sell MMV Non-Vendor Placing
Shares without reference to the restrictions set forth in this section 2.9.


                                      -16-

<PAGE>

                                    ARTICLE 3
                         REPRESENTATIONS AND WARRANTIES

3.1  VENDORS' REPRESENTATIONS AND WARRANTIES

          The Vendor hereby represents and warrants to each of the Purchaser and
Vernalis as follows and the Vendor acknowledges that each of the Purchaser and
Vernalis is relying upon the following representations and warranties in
connection with the purchase of the Purchased Shares (and such representations
and warranties shall be deemed to be repeated on at the Time of Closing and, in
the case of the representation and warranty contained in section 3.1.11, unless
the Purchaser and Vernalis have been otherwise notified in writing at least 10
Business Days prior thereto, on each Redemption Date or date of payment under
section 2.4.8):

     3.1.1 INCORPORATION. It is duly incorporated and validly existing under the
     laws of its jurisdiction of incorporation.

     3.1.2 CAPACITY AND DUE AUTHORIZATION. It has the corporate power and
     capacity to enter into, and to perform its obligations under, this
     Agreement.

     3.1.3 ENFORCEABILITY. This Agreement has been duly authorized, executed and
     delivered by it and is its valid and binding obligation, enforceable
     against it in accordance with its terms, subject to the usual exceptions as
     to bankruptcy and the availability of equitable remedies.

     3.1.4 TITLE TO, AND RIGHT TO, SELL PURCHASED SHARES. It is the sole
     registered and beneficial owner of the Purchased Shares with good and
     marketable title thereto, free of all Charges. There are no agreements or
     restrictions which in any way limit or restrict the transfer to the
     Purchaser of its Purchased Shares nor are there any shareholders
     agreements, pooling agreements, voting trusts or other agreements or
     understandings with respect to the voting of its Purchased Shares or any of
     them. At the Time of Closing, it will have full legal right, power and
     authority to sell the Purchased Shares to the Purchaser free of all
     Charges.

     3.1.5 AMOUNTS OWING BY THE CORPORATION. At the Time of Closing, upon
     exercise of all options, warrants, conversion rights to acquire shares or
     securities of the Corporation, there shall be no amounts owing to the
     Vendor by the Corporation, subject to prepayment of the MMV Loan in
     accordance with section 4.2.1.

     3.1.6 NO CONTRAVENTION. None of the entering into of this Agreement nor the
     performance by it of any of its obligations under this Agreement will
     contravene, breach or result in any default under its articles, by-laws,
     constating documents or other organizational documents, if applicable, or
     under any mortgage, lease, agreement, other legally binding instrument,
     licence, permit, statute, regulation, order, judgment, decree or law to
     which it is a party or by which it may be bound.

     3.1.7 CONSENTS AND APPROVALS. No authorization, consent or approval of, or
     filing with or notice to, any governmental agency, regulatory body, court
     or other Person is


                                      -17-

<PAGE>

     required in connection with the execution, delivery or performance by it of
     this Agreement or the sale by it of any of the Purchased Shares hereunder.

     3.1.8 COMPLIANCE WITH CONFIDENTIALITY OBLIGATIONS. It has complied with all
     applicable confidentiality or proprietary obligations in favour of the
     Corporation and has not, directly of indirectly, used for its own purposes
     or disclosed to any Person any confidential or proprietary information of
     the Corporation or the Subsidiaries, including know-how and data, technical
     or non-technical, relating to the Business.

     3.1.9 PRINCIPAL PURCHASE AGREEMENT. It acknowledges that it is aware of the
     terms of the Principal Purchase Agreement and that, if requested, it
     received a copy of the Principal Purchase Agreement.

     3.1.10 TAX RESIDENCY. It is not a non-resident of Canada under the Income
     Tax Act (Canada).

     3.1.11 U.S. SECURITIES LAWS. It is not located or resident in the United
     States of America for securities laws purposes.

3.2  PURCHASER'S AND VERNALIS' REPRESENTATIONS AND WARRANTIES

          The Purchaser and Vernalis each jointly and severally represents and
warrants to the Vendor as follows and acknowledges that the Vendor is relying
upon the following representations and warranties in connection with its sale of
the Purchased Shares (and such representations and warranties shall be deemed to
be repeated at the Time of Closing):

     3.2.1 INCORPORATION. The Purchaser is duly incorporated and validly
     existing under the laws of New Brunswick. Vernalis is duly incorporated and
     validly existing under the laws of England and Wales.

     3.2.2 CORPORATE POWER AND DUE AUTHORIZATION. The Purchaser and Vernalis
     each have the corporate power and capacity to enter into, and to perform
     its obligations under, this Agreement, subject to shareholder and
     regulatory approvals and requirements and filings in connection with the
     issue of securities of the Purchaser and Vernalis as contemplated herein.
     This Agreement has been duly authorized by the board of directors of each
     of the Purchaser and Vernalis. This Agreement has been duly executed and
     delivered by the Purchaser and Vernalis.

     3.2.3 ENFORCEABILITY. This Agreement is a valid and binding obligation of
     each of the Purchaser and Vernalis, enforceable in accordance with its
     terms, subject to the usual exceptions as to bankruptcy and the
     availability of equitable remedies.

     3.2.4 NO CONTRAVENTION. None of the entering into of this Agreement nor the
     performance by the Purchaser nor Vernalis of any of its obligations under
     this Agreement will contravene, breach or result in any default under its
     articles, by-laws, constating documents or other organizational documents
     or under any mortgage, lease, agreement, other legally binding instrument,
     licence, permit, statute, regulation, order, judgment, decree or law to
     which it is a party or by which it may be bound.


                                      -18-

<PAGE>

     3.2.5 CONSENTS AND APPROVALS. No authorization, consent or approval of, or
     filing with or notice to, any governmental agency, regulatory body, court
     or other Person is required in connection with the execution, delivery or
     performance by the Purchaser nor Vernalis of this Agreement nor the
     performance by it of any of its obligations, subject to shareholder and
     regulatory approvals and requirements and filings in connection with the
     issue of securities of the Purchaser and Vernalis as contemplated herein.

     3.2.6 ISSUE OF PURCHASER SHARES AND VERNALIS SHARES. At the time of issue
     of the Purchaser Shares or Vernalis Shares in accordance with the share
     provisions attached to the Purchaser Shares and the provisions of this
     Agreement, such Purchaser Shares and Vernalis Shares, as the case may be,
     shall be validly issued and fully paid.

                                    ARTICLE 4
                                    COVENANTS

4.1  VENDOR'S COVENANTS

          The Vendor covenants in favour of the Purchaser and Vernalis as
follows:

     4.1.1 EXERCISE OF RIGHTS. To exercise, prior to the Time of Closing, all
     warrants, conversion rights, options and other rights to acquire, directly
     or indirectly, Corporation Shares prior to the Time of Closing.

     4.1.2 RELEASE OF CHARGES. To release, upon prepayment of the MMV Loan in
     accordance with section 4.2.1, the Corporation from all Charges against the
     property, assets or undertaking of the Corporation granted in favour of the
     Vendor and to authorize the Corporation and the Purchaser, jointly and
     severally, to discharge all such Charges forthwith thereafter. The Vendor
     hereby waives notice of prepayment of the MMV Loan in accordance with
     section 4.2.1 and covenants and agrees to execute such further assurances,
     discharges or releases as may be necessary to discharge all Charges against
     the property, assets or undertaking of the Corporation.

     4.1.3 PURCHASER SHAREHOLDERS AGREEMENT. To enter into, at the Time of
     Closing, the Purchaser Shareholders Agreement and hereby authorizes the
     Vendors' Representative to execute the Purchaser Shareholders Agreement on
     its behalf.

     4.1.4 VENDORS' REPRESENTATIVE AGREEMENT. To enter into, at the Time of
     Closing, the Vendors' Representative Agreement.

     4.1.5 WITHDRAWAL RIGHT. To not exercise, or attempt to exercise, any right
     or entitlement which may be applicable to, or enforceable by, it under
     section 87(Q) of the Financial Services and Markets Act 2000 (United
     Kingdom) (as amended). The Vendor acknowledges that the issue of Vernalis
     Shares to it under this Agreement will be by way of a bilateral contract
     and as such section 87(Q) will not entitle it to withdraw in the event that
     Vernalis publishes a supplementary prospectus. The Vendor covenants in
     favour of Vernalis that, in the event it is so entitled to withdraw,


                                      -19-

<PAGE>

     by signing this Agreement, it is confirming its acceptance of the offer of
     Vernalis Shares contained in this Agreement on the same terms immediately
     after such withdrawal.

4.2  PURCHASER'S COVENANTS

          The Purchaser covenants in favour of the Vendor as follows:

     4.2.1 PREPAYMENT OF THE MMV LOAN. To prepay at the Time of Closing, the MMV
     Loan (together with interest accrued thereon to but excluding the date of
     Closing) and the Make-Whole Payment (as defined therein) calculated to but
     excluding the Closing Date.

                                    ARTICLE 5
                                 GENERAL MATTERS

5.1  CONFIDENTIALITY

     5.1.1 The Vendor shall not directly or indirectly use for its own purposes
     or disclose to any other Person any confidential or proprietary
     information, including know-how and data, technical or non-technical,
     relating to the business of Vernalis which becomes known to the Vendor or
     its accountants, legal advisers or representatives as a result of Vernalis
     making the same available in connection with the transaction contemplated
     hereby.

     5.1.2 The Vendor shall not directly or indirectly use for its own purposes
     or disclose to any Person any confidential or proprietary information of
     the Corporation or the Subsidiaries, including know-how and data, technical
     or non-technical, relating to the Business.

5.2  PUBLIC NOTICES

          No press release or other public announcement concerning the
transaction contemplated by this Agreement shall be made by the Vendor without
the prior written consent of Vernalis.

5.3  EXPENSES

          Each of the Vendor, the Purchaser and Vernalis shall be responsible
for the expenses (including fees and expenses of legal advisers, accountants and
other professional advisers) incurred by it in connection with the negotiation
and settlement of this Agreement and the completion of the transactions
contemplated hereby.

5.4  TERMINATION

          This Agreement shall terminate and the obligations and covenants of
the parties hereunder, other than those set out in sections 5.1, 5.2 and 5.3,
shall terminate upon the


                                      -20-

<PAGE>

termination of the Principal Purchase Agreement but shall not terminate prior
thereto in any circumstances.

5.5  ASSIGNMENT

          Except as provided in this section, no party may assign its rights or
benefits under this Agreement, nor may a Vendor transfer its Purchaser Shares
except to Vernalis or an affiliate of Vernalis. The Purchaser or Vernalis may,
at any time after the Time of Closing and from time to time, assign its rights
and benefits under this Agreement, in whole or in part, to any affiliate or to
any Person who acquires all or substantially all of the assets or shares of the
Corporation.

5.6  NOTICES

          Any notice or other communication required or permitted to be given
hereunder shall be in writing and shall be given by prepaid mail, by facsimile
or other means of electronic communication or by hand-delivery as hereinafter
provided. Any such notice or other communication, if mailed by prepaid mail at
any time other than during a general discontinuance of postal service due to
strike, lockout or otherwise, shall be deemed to have been received on the
seventh Business Day after the post-marked date thereof, or if sent by facsimile
or other means of electronic communication, shall be deemed to have been
received on the Business Day following the sending, or if delivered by hand
shall be deemed to have been received at the time it is delivered to the
applicable address noted below either to the individual designated below or to
an individual at such address having apparent authority to accept deliveries on
behalf of the addressee. Notice of change of address shall also be governed by
this section 5.6. In the event of a general discontinuance of postal service due
to strike, lock-out or otherwise, notices or other communications shall be
delivered by hand or sent by facsimile or other means of electronic
communication and shall be deemed to have been received in accordance with this
section 5.6. Notices and other communications shall be addressed as follows:

     (a)  if to the Vendor:

          MMV Financial Inc.
          95 Wellington Street West
          22nd Floor
          Toronto, Ontario
          M5J 2N7

          Attention:         Brian Hendry, Senior Vice-President
          Telecopier number: (416) 591-1393


                                      -21-

<PAGE>

          with a copy to the Vendor's counsel at:

          Aird & Berlis LLP
          Suite 1800, BCE Place
          Toronto, Ontario
          M5J 2T9

          Attention:         Tony Gioia
          Telecopier number: 416-863-1515

          and with a copy to the Vendors' Representative at:

          The VenGrowth Advanced Life Sciences Fund Inc.
          105 Adelaide Street West, Suite 1000
          Toronto, Ontario
          M5H 1P9

          Attention:         Dr. Luc Marengere/Phil Kurtz
          Telecopier number: 416-971-6519

     (b)  if to the Purchaser or Vernalis:

          Vernalis plc
          Oakdene Court
          613 Reading Road
          Winnersh, Berkshire
          RG 41 5UA

          Attention:         John Slater
          Telecopier number: + 44 118 989 9300

          with a copy to the Purchaser's counsel at:

          Torys LLP
          Suite 3000, 79 Wellington Street West
          Box 270, TD Centre
          Toronto, Ontario M5K 1N2

          Attention:         Kathleen L. Keller-Hobson
          Telecopier number: (416) 865-7380

          and to:


                                      -22-

<PAGE>

          Allen & Overy LLP
          One New Change
          London EC4M 9QQ
          United Kingdom

          Attention:         Anna Buscall
          Telecopier number: + 44 20 7330 9999

          The failure to send or deliver a copy of a notice to the Purchaser's
Counsel or the Vendor's Counsel, as the case may be, shall not invalidate any
notice given under this section 5.6.

5.7  TIME OF ESSENCE

          Time is of the essence of this Agreement.

5.8  FURTHER ASSURANCES

          Each of the parties shall promptly do, make, execute, deliver, or
cause to be done, made, executed or delivered, all such further acts, documents
and things as the other party hereto may reasonably require from time to time
for the purpose of giving effect to this Agreement and shall use reasonable
efforts and take all such steps as may be reasonably within its power to
implement to their full extent the provisions of this Agreement.

5.9  COUNTERPARTS

          This Agreement may be signed in counterparts and each such counterpart
shall constitute an original document and such counterparts, taken together,
shall constitute one and the same instrument.


                                      -23-

<PAGE>

          IN WITNESS WHEREOF the parties hereto have executed this Agreement.

                                        MMV FINANCIAL INC.


                                        by:
                                            ------------------------------------
                                        Name:
                                              ----------------------------------
                                        Title:
                                               ---------------------------------


                                        by:
                                            ------------------------------------
                                        Name:
                                              ----------------------------------
                                        Title:
                                               ---------------------------------


                                        VERNALIS PLC


                                        by:
                                            ------------------------------------
                                        Name:
                                              ----------------------------------
                                        Title:
                                               ---------------------------------


                                        VERNALIS (CANADA) INC.


                                        by:
                                            ------------------------------------
                                        Name:
                                              ----------------------------------
                                        Title:
                                               ---------------------------------

          The undersigned hereby agrees to act as the Vendors' Representative
and to carry out such duties and responsibilities on behalf of the Vendor as
provided in this Agreement.

                                        THE VENGROWTH ADVANCED LIFE SCIENCES
                                        FUND INC., as Vendors'
                                        Representative


                                        by:
                                            ------------------------------------
                                        Name:
                                              ----------------------------------
                                        Title:
                                               ---------------------------------


                                        by:
                                            ------------------------------------
                                        Name:
                                              ----------------------------------
                                        Title:
                                               ---------------------------------

                                       Signature Page for MMV Purchase Agreement