<PAGE>

                                                                    EXHIBIT 10.2
                                                                    ------------


                            STOCK PURCHASE AGREEMENT


THIS AGREEMENT is made on August 2, 2000 in the City of Montreal, Quebec.


BETWEEN:            METHYLGENE INC., a corporation incorporated under the laws
                    of Canada (hereinafter referred to as the "Corporation")

AND:                MGI PHARMA INC., a corporation incorporated under the laws
                    of the State of Minnesota (hereinafter referred to as "MGI")

WHEREAS the Corporation is a Canadian bio-pharmaceutical corporation engaged in,
among other activities, the business of research and development of novel
therapeutic compounds, and possesses certain technologies, licenses, patents and
expertise relating to thereto;

WHEREAS MGI is an American pharmaceutical corporation engaged in, among other
activities, the acquisition, development and commercialization of drugs
primarily for the treatment of cancer and rheumatology disorders;

AND WHEREAS MGI intends to make an equity investment in, and make other payments
to the Corporation on the terms and conditions hereinafter more fully set forth.

NOW THEREFORE THIS AGREEMENT WITNESSES that, in consideration of the premises
and the covenants and agreements herein contained, the parties hereto agree as
follows:

                           Article I - INTERPRETATION

1.1      Definitions
         -----------

In this Agreement, unless something in the subject matter or context is
inconsistent therewith:

"Agreement" means this agreement and all amendments made hereto by written
agreement between the Corporation and MGI;

"Balance Sheet Date" means December 31, 1999;

"Business day" means a day of the year other than a Saturday or Sunday or
statutory holiday in the Province of Quebec or the State of Minnesota;

"Class A Shares" means the Class A Shares of the Corporation;

"Financial Information" means the information in the audited financial
statements of the Corporation as at December 31, 1999, together with the
auditors' report thereon, a copy of which is attached hereto as Schedule "A";
<PAGE>

                                       -2-


"First Equity Closing Date" means August 2, 2000, or such later date as may be
agreed to by the parties hereto in writing, but in no event later than August 9,
2000;

"First Equity Purchased Shares" has the meaning ascribed thereto in section
2.1(a);

"First Equity Purchase Price" has the meaning ascribed thereto in section
2.1(a);

"Latest Balance Sheet" means the audited balance sheet of the Corporation as at
December 31, 1999, which is included in the Financial Information;

"License Agreement" means that certain License Agreement dated as of August 2,
2000 between the parties hereto;

"Material Change" means a material change for purposes of any of the Securities
Laws;

"Material Fact" means a material fact for purposes of any of the Securities
Laws;

"Misrepresentation" means a misrepresentation for purposes of any of the
Securities Laws;

"Offering" means either the initial public offering of shares of the Corporation
or the closing of a private placement of Class A Shares which results in
aggregate net proceeds to the Corporation of not less than CDN $5,000,000 (but
excluding the Second Equity Purchase Price), which private placement may include
the second tranche of that certain private placement by the Corporation which
closed on July 14, 2000.

"Purchased Shares" means collectively the First Equity Purchased Shares and the
Second Equity Purchased Shares;

"Purchase Price" means the First Equity Purchase Price or the Second Equity
Purchase Price, as the case may be.

"Second Equity Purchase Price" has the meaning ascribed thereto in section
6.1(a);

"Second Equity Purchased Shares" has the meaning ascribed thereto in section
6.1(a);

"Second Equity Closing Date" means the earliest to occur of the closing date of
the Offering or March 31, 2001, or such later date as may be agreed to by the
parties hereto in writing;

"Securities Laws" means, collectively, the applicable securities laws of each of
the provinces of Canada and the respective regulations made thereunder together
with all applicable published policy statements, blanket orders and rulings of
the securities regulatory authorities in such provinces;

"Shareholders' Agreement" means that certain shareholders' agreement of the
Corporation dated as of January 4, 1996, as amended, a copy of which is attached
hereto as Schedule "B";

"Subsidiary" has the meaning ascribed thereto in the Canada Business
Corporations Act;

"Time of Closing" means 2:00 p.m. (Montreal time) on the First Equity Closing
Date or the Second Equity Closing Date, as the case may be;.
<PAGE>

                                      -3-


"Unanimous Shareholders' Agreement" means that certain Unanimous Shareholders'
Agreement of the Corporation dated January 4, 1996, as amended, a copy of which
is attached as Schedule "C" hereto.

1.2      Headings
         --------

The division of this Agreement into Articles and Sections and the insertion of
headings are for the convenience of reference only and do not affect the
construction or interpretation of this Agreement. The terms "this Agreement",
"hereof", "hereunder" and similar expressions refer to this Agreement and not to
any particular Article, Section or other portion hereof and include any
agreement or instrument supplemental or ancillary hereto. Unless something in
the subject matter or context is inconsistent therewith, references herein to
Articles and Sections are to Articles and Sections of this Agreement.

1.3      Extended Meanings
         -----------------

In this Agreement, words importing the singular number include the plural and
vice versa, words importing any gender include all genders and words importing
persons include individuals, partnerships, associations, trusts, unincorporated
organizations and corporations.

                 Article II - PURCHASE AND SALE OF FIRST EQUITY

2.1      First Equity Purchase and Sale and Purchase Price
         -------------------------------------------------

         (a)      The Corporation will sell Class A Shares to MGI and MGI will
                  purchase such shares (the "First Equity Purchased Shares")
                  from the Corporation for a total purchase price of US$3.80
                  million (the "First Equity Purchase Price"), at a price of
                  CDN$3.30 per First Equity Purchased Share upon and subject to
                  the terms and conditions hereof. For purposes of determining
                  the number of First Equity Purchased Shares, the parties agree
                  to use the exchange rate for converting Canadian dollars into
                  U.S. dollars as published in the Wall Street Journal on the
                  day immediately preceding the day of the First Equity Closing
                  Date.

         (b)      The First Equity Purchase Price will be paid and satisfied by
                  certified cheque, bank draft or wire transfer payable at par
                  in U.S. dollars in Montreal to or to the order of the
                  Corporation and delivered by MGI at the Time of Closing
                  against delivery to MGI of a certificate evidencing the First
                  Equity Purchased Shares registered in the name of MGI.

2.2      Closing
         -------

The sale and purchase of the First Equity Purchased Shares will be completed at
the Time of Closing at the offices of Goodman Phillips & Vineberg, Montreal,
Quebec.
<PAGE>

                                      -4-


                  Article III - REPRESENTATIONS AND WARRANTIES

3.1      Corporation's Representations and Warranties
         --------------------------------------------

The Corporation represents and warrants to MGI, and acknowledges that MGI is
relying thereon, that:

         (a)      the Corporation has been duly incorporated and is validly
                  existing under the laws of its jurisdiction of incorporation
                  and is conducting its business in all material respects in
                  compliance with all applicable laws, rules and regulations of
                  each jurisdiction in which it carries on business and holds
                  all material licenses, registrations and qualifications in all
                  jurisdictions in which it carries on business necessary to
                  carry on its business as now conducted;

         (b)      the Corporation has not taken any corporate action nor have
                  any other steps been taken or legal proceedings been started
                  or, to the Corporation's knowledge, threatened against the
                  Corporation for its winding-up, dissolution, liquidation or
                  reorganization or for the appointment of a receiver, trustee
                  or similar officer of it or any or all of its assets or
                  revenues;

         (c)      the authorized capital of the Corporation consists of an
                  unlimited number of Class A Shares, an unlimited number of
                  Class B Shares and an unlimited number of Class C Shares, of
                  which, as at the date hereof, 12,342,980 Class A Shares,
                  3,402,941 Class B Shares and 39,500 Class C Shares are issued
                  and outstanding, all of which are duly authorized, validly
                  issued, fully paid and nonassessable;

         (d)      no person has any agreement, option, right or privilege with
                  or against the Corporation for the purchase, subscription or
                  issuance of securities, issued or unissued of the Corporation,
                  other than MGI pursuant to the provisions hereof, the
                  Corporation's existing stock option programs and any
                  securities which may be issued or issuable as a result of the
                  exercise by a shareholder of the pre-emptive right set forth
                  in the Shareholders' Agreement;

         (e)      the Corporation has good and sufficient corporate power,
                  authority and right to enter into this Agreement; on the First
                  Equity Closing Date, this Agreement and the transactions to be
                  completed by the Corporation hereunder will have been duly
                  authorized by all necessary corporate action on the part of
                  the Corporation; and this Agreement has been duly executed and
                  delivered by the Corporation and is a legally binding
                  obligation of the Corporation enforceable against it in
                  accordance with its terms, subject to bankruptcy and
                  insolvency laws and other laws generally affecting the
                  enforceability of creditors' rights and the availability of
                  the equitable remedies;

         (f)      the execution and delivery of this Agreement, the fulfilment
                  of the terms hereof by the Corporation and the issue, sale and
                  delivery at the Time of Closing of the Purchased Shares do not
                  and will not violate, conflict with or result in any breach of
                  the articles, by-laws or resolutions of the Corporation or any
                  agreement or instrument to which the Corporation is a party or
                  by which it is contractually bound, or any law, statute, rule,
                  regulation, order judgment or decree to which
<PAGE>

                                      -5-


                  the Corporation or its properties are subject, other than such
                  violations, conflicts or breaches that in the aggregate would
                  not have a material adverse effect on the condition, financial
                  or otherwise, or the earnings, business affairs or business
                  prospects of the Corporation;

         (g)      subject to payment therefor, the Purchased Shares to be
                  delivered to you on the First Equity Closing Date and on the
                  Second Equity Closing Date will have been duly authorized by
                  all necessary corporate action on the part of the Corporation
                  and will be duly issued as fully paid and nonassessable shares
                  of the Corporation;

 (h) the
                  Financial Information presents fairly the financial position
                  of the Corporation as at the dates indicated and the results
                  of its operations for the periods specified and the said
                  Financial Information has been prepared in conformity with
                  generally accepted accounting principles in Canada applied on
                  a consistent basis;

         (i)      the Corporation is (i) not in violation of its articles or
                  by-laws and (ii) is not in default in the performance or
                  observance of any obligation, agreement, covenant or condition
                  contained in any contract, indenture, mortgage, loan
                  agreement, note, lease or other instrument to which it is a
                  party or by which it may be bound or to which any of its
                  property or assets is subject, other than defaults that in the
                  aggregate do not have a material adverse effect on the
                  condition, financial or otherwise, or the earnings, business
                  affairs or business prospects of the Corporation;

         (j)      there are no actions, suits, proceedings or inquiries pending
                  or threatened in writing against or affecting the Corporation
                  at law or in equity or before or by any federal, provincial,
                  state, municipal or other governmental department, commission,
                  board, bureau, agency or instrumentality, domestic or foreign,
                  which may in any way materially adversely affect the
                  Corporation or the transactions contemplated hereby;

         (k)      no authorization, approval or consent of any court or
                  governmental or regulatory authority is required to be
                  obtained by the Corporation in connection with the sale and
                  delivery of the Purchased Shares hereunder, except as may be
                  required under the Shareholders' Agreement, the Unanimous
                  Shareholders' Agreement and except such as have been obtained;

         (l)      the Corporation has no Subsidiary;

         (m)      except as reflected in the Latest Balance Sheet, the
                  Corporation has no liabilities (whether accrued, absolute,
                  contingent, unliquidated or otherwise, whether due or to
                  become due, whether known or unknown, and regardless of when
                  asserted) arising out of transactions or events heretofore
                  entered into, or any action or inaction, or any state of facts
                  existing, with respect to or based upon transactions or events
                  heretofore occurring, except liabilities which have arisen
                  after the Balance Sheet Date in the ordinary course of
                  business (none of which is a material uninsured liability for
                  breach of contract, breach of warranty, tort, infringement,
                  claim or lawsuit);
<PAGE>

                                      -6-


         (n)      since the Balance Sheet Date, there has been no material
                  adverse change in the assets, financial condition, operating
                  results, customer, employee or supplier relations, business
                  condition or prospects of the Corporation;


         (o)      the Corporation owns and possesses all right, title and
                  interest, or holds a valid license, in and to all rights in
                  patents, patent applications, trademarks, service marks, trade
                  names, corporate names, copyrights, trade secrets, know-how or
                  other intellectual property rights owned by, licensed to or
                  otherwise controlled by the Corporation or used in, developed
                  for use in or necessary to the conduct in all material
                  respects of the Corporation's business as now conducted (the
                  "Intellectual Property Rights"); the Corporation has not
                  received any notice of any infringement or misappropriation
                  by, or conflict from, any third party with respect to the
                  Intellectual Property Rights; no claim by any third party
                  contesting the validity of any Intellectual Property Rights
                  has been made, is currently outstanding or, to the best
                  knowledge of the Corporation, is threatened; the Corporation
                  has not received any notice of any infringement,
                  misappropriation or violation by the Corporation of any
                  intellectual property rights of any third parties and, to the
                  best of its knowledge, the Corporation has not infringed,
                  misappropriated or otherwise violated any such intellectual
                  property rights;

         (p)      to the best knowledge of the Corporation, no executive
                  employee of the Corporation and no group of the Corporation's
                  employees has any plans to terminate his or its employment;
                  the Corporation has complied in all material respects with all
                  laws relating to the employment of labor, including provisions
                  thereof relating to wages, hours, collective bargaining and
                  the payment of social security and other taxes; the
                  Corporation has no material labor relations problem pending
                  and its labor relations are satisfactory; and to the best
                  knowledge of the Corporation, no employee of the Corporation
                  is subject to any secrecy or noncompetition agreement or any
                  other agreement or restriction of any kind that would impede
                  in any material way the ability of such employee to carry out
                  fully all activities of such employee in furtherance of the
                  business of the Corporation;

         (q)      the Corporation and its officers, directors, agents and
                  employees have complied in all material respects with all
                  applicable laws, regulations and other requirements,
                  including, but not limited to, federal, provincial, local and
                  foreign laws, ordinances, rules, regulations and other
                  requirements which materially affect the business of the
                  Corporation or its property and to which the Corporation or
                  its property may be subject, and no claims have been filed
                  against the Corporation alleging a material violation of any
                  such laws, regulations or other requirements;

         (r)      the Corporation has, in full force and effect, all licenses,
                  permits and certificates, from federal, provincial, local and
                  foreign authorities necessary to conduct in all material
                  respects its business and own and operate its properties, and
                  the Corporation has conducted its business in compliance with
                  all material terms and conditions of such licenses, permits
                  and certificates; and

         (s)      neither this Agreement nor any of the documents provided to
                  MGI by or on behalf of the Corporation nor the Financial
                  Information, taken as a whole, contain any untrue statement of
                  a material fact regarding the Corporation or its business or
<PAGE>

                                      -7-


                  the transactions contemplated by this Agreement; this
                  Agreement, the documents provided to MGI by or on behalf of
                  the Corporation and the Financial Information, taken as a
                  whole, do not omit any material fact necessary to make the
                  statements contained herein or therein, in light of the
                  circumstances in which they were made, not misleading.

3.2      Survival of the Corporation's Representations and Warranties
         ------------------------------------------------------------

The representations and warranties of the Corporation set forth in Section 3.1
will survive the completion of the sale and purchase of the Purchased Shares
herein provided for and will continue in full force and effect for the benefit
of MGI for a period of two (2) years from the Second Equity Closing Date,
unaffected by any investigation made by or on behalf of MGI in the course of
preparation of this Agreement.

3.3      MGI's Representations and Warranties
         ------------------------------------

MGI represents and warrants to the Corporation that:

         (a)      MGI is a corporation duly incorporated and in good standing
                  under the laws of the State of Minnesota, with good and
                  sufficient corporate power, authority and right to enter into
                  and deliver this Agreement and to complete the transactions to
                  be completed by MGI contemplated hereby; this Agreement and
                  the transactions to be completed by MGI hereunder have been
                  duly authorized by all necessary corporate action on the party
                  of MGI; and this Agreement has been duly executed and
                  delivered by MGI;

         (b)      the execution and delivery of this Agreement and the
                  fulfilment of the terms hereof by MGI do not and will not
                  violate, conflict with or result in any breach of the
                  articles, by-laws or resolutions of MGI or any agreement or
                  instrument to which MGI is a party or by which it is
                  contractually bound, or any law, statute, rule, regulation,
                  order judgment or decree to which MGI or its properties are
                  subject, other than any such violation, conflict or breach
                  which would not materially adversely affect MGI;

         (c)      MGI is purchasing all of the Purchased Shares as principal for
                  its own account and not for the benefit of any other person
                  and not with a view to resale or distribution of all or any of
                  the Purchased Shares.

         (d)      MGI has not been created solely to permit the purchase without
                  a prospectus of the Purchased Shares;

         (e)      MGI acknowledges that the foregoing representations and
                  warranties are made by MGI with the intent that they may be
                  relied upon in determining its eligibility to purchase the
                  Purchased Shares under the Securities Laws and applicable U.
                  S. securities laws and MGI hereby agrees to indemnify the
                  Corporation against all losses, claims, costs, expenses and
                  damages and other liabilities which any of them may suffer or
                  incur as the result of or arising from the reliance by the
                  Corporation on any such representation or warranty.
<PAGE>

                                      -8-


         (f)      MGI acknowledges that the resale by MGI of the Purchased
                  Shares is subject to certain restrictions under the Securities
                  Laws and that MGI will sell the Purchased Shares only in
                  compliance with any such restrictions applicable to MGI at the
                  time of such sale.

3.4      Survival of MGI's Representations and Warranties
         ------------------------------------------------

The representations and warranties of MGI set forth in Section 3.3 will survive
the completion of the sale and purchase of the Purchased Shares herein provided
for and will continue in full force and effect for the benefit of the
Corporation for a period of two (2) years from the Second Equity Closing Date,
unaffected by any investigation made by or on behalf of the Corporation in the
course of the preparation of this Agreement.
                             Article IV - COVENANTS

4.1      Covenants of the Corporation
         ----------------------------

The Corporation covenants and agrees with MGI that:

         (a)      subject to receipt of the Purchase Price therefor, the
                  Purchased Shares will at the applicable Time of Closing be
                  duly and validly allotted and issued to MGI as fully-paid and
                  non-assessable shares;

         (b)      the Corporation will promptly inform MGI in writing prior to
                  each Time of Closing of the full particulars of:

                  (i)      any Material Change (actual, anticipated,
                           contemplated or threatened, whether financial or
                           otherwise) in the business, affairs, operations,
                           assets, liabilities (contingent or otherwise) or
                           capital of the Corporation, and

                  (ii)     any change in any Material Fact contained in the
                           Financial Information;

                  that has occurred since the date hereof;

         (c)      the Corporation will indemnify and save harmless MGI against
                  all losses, claims, damages, liabilities, costs or expenses
                  caused or incurred, directly or indirectly, by reason of any
                  breach of any covenant of the Corporation contained in this
                  Agreement or any inaccuracy or misrepresentation in any
                  representation or warranty set forth in Section 3.1; and

         (d)      the Corporation will nominate, and will use its best efforts
                  to ensure that the shareholders of the Corporation elect, one
                  member of the Board of Directors of the Corporation designated
                  by MGI (the "MGI Designee"), provided that the MGI Designee
                  will resign from the Board of Directors of the Corporation
                  immediately upon the expiry or termination for any reason of
                  the License Agreement.
<PAGE>

                                      -9-


4.2      Covenants of MGI
         ----------------

MGI covenants and agrees with the Corporation that:

         (a)      If required by applicable securities legislation or other
                  securities regulatory requirements, MGI will execute, deliver
                  and file or assist the Corporation in obtaining and filing
                  such reports, undertakings, and other documents with respect
                  to the creation and sale of the Purchased Shares as may be
                  required by any securities commission, stock exchange or other
                  regulatory authority;

         (b)      MGI will (i) not sell or otherwise dispose of any Purchased
                  Shares, except in accordance with applicable Securities Laws,
                  (ii) if MGI sells or otherwise disposes of any Purchased
                  Shares to a person other than a resident of Canada, obtain
                  from such purchaser a covenant in the same form as provided
                  herein in these subparagraphs (i) and (iii), and (iii) not
                  transfer or otherwise dispose of any Purchased Shares in
                  violation of the registration requirements of the U.S.
                  Securities Act of 1933, as amended, or any applicable U.S.
                  state securities or blue sky laws;

         (c)      MGI will indemnify and save harmless Corporation against all
                  losses, claims, damages, liabilities, costs or expenses caused
                  or incurred, directly or indirectly, by reason of any breach
                  of any covenant of MGI contained in this Agreement or any
                  inaccuracy or misrepresentation in any representation or
                  warranty set forth in Section 3.3; and

         (d)      the MGI Designee will resign from the Board of Directors of
                  the Corporation immediately upon the expiry or termination for
                  any reason of the License Agreement.


                             Article V - CONDITIONS

5.1      Conditions for the Benefit of MGI
         ---------------------------------

         (a)      The obligation of MGI to purchase Purchased Shares on the
                  First Equity Closing Date or the Second Equity Closing Date,
                  as the case may be, is subject to the following terms and
                  conditions which are for the exclusive benefit of MGI to be
                  performed or complied with at or prior to the Time of Closing:

                  (i)      the representations and warranties of the Corporation
                           set forth in Section 3.1 will be true and correct at
                           the Time of Closing with the same force and effect as
                           if made at and as of such time;

                  (ii)     the Corporation will have performed or complied with
                           all of the terms, covenants and conditions of this
                           Agreement to be performed or complied with by the
                           Corporation at or prior to the Time of Closing,
                           including without limitation its obligation to
                           deliver a certificate evidencing the
<PAGE>

                                      -10-


                           Purchased Shares pursuant to section 2.1(b) or
                           section 6.1(b), as the case may be;

                  (iii)    all actions required to be taken by or on behalf of
                           the Corporation, including the passing of all
                           requisite resolutions of the board of directors of
                           the Corporation and all filings, if any, with
                           regulatory authorities, will have occurred at or
                           prior to the Time of Closing so as to validly issue
                           the Purchased Shares;

                  (iv)     at or before the Time of Closing, the Corporation
                           will have caused a favorable legal opinion to be
                           delivered by Goodman Phillips & Vineberg to MGI in
                           form reasonably satisfactory to MGI and to MGI's
                           legal counsel with respect to the following matters
                           and acceptable to MGI and its counsel, acting
                           reasonably:

                           (1)      the Corporation is a corporation
                                    incorporated and validly subsisting under
                                    the laws of Canada;

                           (2)      the Corporation has the requisite corporate
                                    power and authority to perform its
                                    obligations under the terms of this
                                    Agreement;

                           (3)      the Purchased Shares have been validly
                                    allotted, and, upon payment therefor, will
                                    be issued as fully paid and non-assessable;

                           (4)      the execution, delivery and performance of
                                    this Agreement have been duly authorized by
                                    the Corporation and this Agreement has been
                                    duly executed and delivered by the
                                    Corporation and is a legally binding
                                    obligation of the Corporation enforceable
                                    against it in accordance with its terms,
                                    subject to bankruptcy and insolvency laws
                                    and other laws generally affecting the
                                    enforceability of creditors' rights and the
                                    availability of the equitable remedies; and

                           (5)      the execution and delivery of this
                                    Agreement, the fulfilment of the terms
                                    hereof by the Corporation and the issue,
                                    sale and delivery at the Time of Closing of
                                    the Purchased Shares do not and will not,
                                    violate, conflict with or result in a breach
                                    of any of the terms, conditions or
                                    provisions of the articles or by-laws of the
                                    Corporation or any statute, law, rule,
                                    regulation, order, judgment or decree
                                    applicable to the Corporation;

                  (v)      MGI will be furnished with such certificates,
                           affidavits or statutory declarations of the
                           Corporation as MGI or MGI's counsel may reasonably
                           think necessary in order to establish that (1) the
                           terms, covenants and conditions contained in this
                           Agreement to have been performed or complied with by
                           the Corporation at or prior to the Time of Closing
                           have been performed or complied with and (2) the
                           representations and warranties of the Corporation
                           herein given are true and correct at the Time of
                           Closing;
<PAGE>

                                      -11-


                  (vi)     MGI and the Corporation will have executed and
                           delivered the License Agreement;

                  (vii)    MGI shall have become a party to the Unanimous
                           Shareholders' Agreement and the Shareholders
                           Agreement and shall have the benefit of, and be bound
                           by, each of the provisions thereof;

                  (viii)   all approvals and consents, if any, required under
                           the Shareholders' Agreement, the Unanimous
                           Shareholders' Agreement or any other agreement of the
                           Corporation in order to avoid a breach, violation or
                           default thereunder as a result of the transactions
                           contemplated hereby, shall have been obtained and any
                           pre-emptive rights under such agreements shall have
                           been waived, exercised or expired.

         (b)      If any term or condition of the Corporation to be performed or
                  complied with prior to or at the Time of Closing is not
                  performed or complied with prior to or at the Time of Closing,
                  MGI may terminate its obligations to purchase any of the
                  Purchased Shares not theretofore purchased hereunder by
                  written notice to that effect given to the Corporation prior
                  to or at the Time of Closing.


5.2      Conditions for the Benefit of the Corporation
         ---------------------------------------------

         (a)      The obligation of the Corporation to sell Purchased Shares on
                  the First Equity Closing Date or the Second Equity Closing
                  Date, as the case may be, is subject to the following terms
                  and conditions which are for the exclusive benefit of the
                  Corporation to be performed or complied with at or prior to
                  the Time of Closing:

                  (i)      the representations and warranties of MGI set forth
                           in Section 3.3 will be true and correct at the Time
                           of Closing with the same force and effect as if made
                           at and as of such time;

                  (ii)     MGI will have performed or complied with all of the
                           terms, covenants and conditions of this Agreement to
                           be performed or complied with by MGI at or prior to
                           the Time of Closing, including without limitation its
                           obligation to deliver the Purchase Price pursuant to
                           section 2.1(b) or section 6.1(b), as the case may be;

                  (iii)    MGI and the Corporation will have executed and
                           delivered the License Agreement.

                  (iv)     MGI shall have become a party to the Unanimous
                           Shareholders' Agreement and the Shareholders
                           Agreement and shall have the benefit of, and be bound
                           by, each of the provisions thereof; and

                  (v)      all approvals and consents, if any, required under
                           the Shareholders' Agreement, the Unanimous
                           Shareholders' Agreement or any other agreement of the
                           Corporation in order to avoid a breach, violation or
                           default thereunder as a result of the transactions
                           contemplated hereby, shall have been obtained and any
                           pre-emptive rights under such agreements shall have
                           been waived, exercised or expired.
<PAGE>

                                      -12-


         (b)      If any term or condition of MGI to be performed or complied
                  with prior to or at the Time of Closing is not performed or
                  complied with prior to or at the Time of Closing, the
                  Corporation may terminate its obligations to sell any of the
                  Purchased Shares not theretofore sold hereunder by written
                  notice to that effect given to MGI prior to or at the Time of
                  Closing.

                Article VI - PURCHASE AND SALE OF SECOND EQUITY

6.1      Second Equity Purchase and Sale and Purchase Price
         --------------------------------------------------

         (a)      On the Second Equity Closing Date, MGI shall purchase shares
                  of the Corporation (the "Second Equity Purchased Shares") for
                  a total purchase price of US$3.0 million (the "Second Equity
                  Purchase Price") upon and subject to the terms and conditions
                  hereof. In the event the Second Equity Purchased Shares are to
                  be purchased by MGI in connection with an initial public
                  offering, MGI shall purchase from the Corporation the same
                  class of shares of the Corporation as are offered pursuant to
                  said offering and at the same price per share as is offered
                  pursuant to said Offering. In the event the Second Equity
                  Purchased Shares are to be purchased by MGI in connection with
                  a private placement within the meaning of the term "Offering",
                  MGI shall purchase from the Corporation Class A Shares at a
                  price equal to the price payable by the other investors in
                  said private placement plus an amount equal to sixteen percent
                  (16%) thereof. In the event that the Second Equity Purchased
                  Shares are to be purchased not in connection with the closing
                  of an Offering, MGI shall purchase from the Corporation Class
                  A Shares at a price per share of CDN$3.30. For purposes of
                  determining the number of Second Equity Purchased Shares, the
                  parties agree to use the exchange rate for converting Canadian
                  dollars into U.S. dollars as published in the Wall Street
                  Journal on the day immediately preceding the day of the Second
                  Equity Closing Date.

         (b)      The Second Equity Purchase Price will be paid and satisfied by
                  a certified cheque, bank draft or wire transfer payable at par
                  in U.S. dollars in Montreal to or to the order of the
                  Corporation and delivered by MGI at the Time of Closing
                  against delivery to MGI of a certificate evidencing the Second
                  Equity Purchase of Shares registered in the name of MGI.

6.2      Closing
         -------

The sale and purchase of the Second Equity Purchased Shares will be completed at
the Time of Closing at the offices of Goodman Phillips & Vineberg, Montreal,
Quebec.
<PAGE>

                                      -13-


                       Article VII - ADJUSTMENT PROVISIONS

7.1      Division or Combination of Shares
         ---------------------------------

If the Corporation at any time divides the outstanding shares of the same class
as the Second Equity Purchased Shares into a greater number of shares (whether
pursuant to a stock split, stock dividend or otherwise), and conversely, if the
outstanding shares of such class are combined into a smaller number of shares,
the price per share of the Corporation's stock used to determine the number of
Second Equity Purchased Shares shall be proportionately adjusted to reflect the
reduction or increase in the value of each such share.

7.2      Reorganization, Recapitalization, Merger, etc.
         ----------------------------------------------

If any capital reorganization, recapitalization or reclassification of the
capital stock of the Corporation, or consolidation or merger of the Corporation
with another corporation, or the sale of all or substantially all of its assets
to another corporation shall be effected in such a way that holders of shares of
the same class as the Second Equity Purchased Shares shall be entitled to
receive stock, securities or assets with respect to or in exchange for such
shares, then, as a condition of such reorganization, reclassification,
consolidation, merger or sale, MGI shall have the right to purchase and receive
upon the basis and upon the terms and conditions specified in this Agreement and
in lieu of the shares of the Corporation immediately theretofore purchasable and
receivable on the Second Equity Closing Date, such shares of stock, other
securities or assets as would have been issued or delivered to MGI if MGI had
purchased and received the Second Equity Purchased Shares immediately prior to
such reorganization, reclassification, consolidation, merger or sale. The
Corporation shall not effect any such consolidation, merger or sale unless prior
to the consummation thereof the successor corporation (if other than the
Corporation) resulting from such consolidation or merger or the corporation
purchasing such assets shall assume in writing the obligation to deliver to MGI
such shares of stock, securities or assets as, in accordance with the foregoing
provisions, MGI may be entitled to purchase.

                             Article VIII - GENERAL
8.1      Notices
         -------

Any demand, notice or other communication to be given in connection with this
Agreement must be given in writing and must be given by personal delivery or by
transmittal by telecopier addressed to the recipient as follows:

         in the case of the Corporation, to:  Methylgene Inc.
                                              Suite 200
                                              7220 Frederick-Banting
                                              St-Laurent, Quebec
                                              H4S 2A1

                                              Attention: President

                                              Facsimile No.: (514) 337-4194
<PAGE>

                                      -14-


         in the case of MGI, to:              MGI Pharma Inc.
                                              Suite 110
                                              6300 West Old Shakopee Road
                                              Bloomington, Minnesota
                                              55438-2318 U.S.A.

                                              Attention: Chief Financial Officer

                                              Facsimile No.:    (952) 346-4920

or such other address or telecopier number or individual as may be designated by
notice by any party to the other. Any communication given by personal delivery
will be conclusively deemed to have been given on the day of actual delivery
thereof and, if given by telecopier, on the day of transmittal thereof if given
during the normal business hours of the recipient and on the business day during
which such normal business hours next occur if not given during such hours on
any day.

8.2      Time of the Essence
         -------------------

Time is of the essence of this Agreement.

8.3      Public Announcements
         --------------------

No public announcement concerning this Agreement shall be made by either party
without prior notice to, and consultation with, the other, except as may be
otherwise required by law or by any stock exchange having jurisdiction over
either party. Notwithstanding the foregoing, (a) MGI understands that the
Corporation is in the process of preparing its initial public offering, and may
be required to disclose the details of this Agreement or its existence in the
prospectus relating thereto, and (b) the Corporation understands that MGI is
subject to disclosure obligations under the U.S. Securities Exchange Act of 1934
and may be required to disclose the existence of this Agreement and make a copy
of the Agreement publicly available as a result thereof. Each of the parties
hereby agrees that it shall submit to the other party the text which it proposes
to include in the prospectus (or equivalent offering document), press release,
public filing or other publication for approval, which approval which will not
be unreasonably withheld or delayed. The party whose approval is sought shall be
deemed to have approved the text submitted if it does not object within two (2)
business days of submission.

8.4      Benefit of the Agreement
         ------------------------

This Agreement will enure to the benefit of and be binding upon the respective
successors and permitted assigns of the parties hereto.

8.5      Amendments and Waiver
         ---------------------

No modification of or amendment to this Agreement will be valid or binding
unless set forth in writing and duly executed by all the parties hereto and no
waiver of any breach of any term or provision of this Agreement will be
effective or binding unless made in writing and signed by the party or parties
purporting to give the same and, unless otherwise provided, will be limited to
the specific breach waived.
<PAGE>

                                      -15-


8.6      Assignment
         ----------

This Agreement may not be assigned by the Corporation or MGI.

8.7      No Agency
         ---------

Each party agrees that it is not an agent of the other party and has no
authority to bind the other party in any matter. This Agreement shall not be
construed so as to constitute either party as a partner, joint venture, agent or
representative of the other party for any purpose whatsoever. Each party shall
be liable for the payment of its own expenses relating to the negotiation and
preparation of this Agreement and shall be responsible to seek and, if possible
obtain, any consents and/or approvals required to be obtained by it.

8.8      Language
         --------

The parties hereto confirm that they have agreed that this Agreement and all
documents relating hereto be drafted in the English language only; les parties
aux presentes confirment qu'elles ont accepte que la presente convention de meme
que tous les documents s'y rattachant soit rediges en anglais seulement.

8.9      Currency
         --------

Unless otherwise specified, all references to dollar amounts in this Agreement
are to the lawful currency of Canada.

8.10     Governing Law
         -------------

This Agreement will be governed by and interpreted and construed in accordance
with the laws of the Province of Quebec and the laws of Canada applicable
therein.
<PAGE>

                                      -16-


IN WITNESS WHEREOF the parties have executed this Agreement.




                                 METHYLGENE INC.



                                 Per:     /s/ Donald F. Corcoran
                                        ----------------------------------------
                                        Donald F. Corcoran
                                        President and CEO




                                 MGI PHARMA INC.



                                 Per:     /s/ Leon O. Moulder, Jr.
                                        ----------------------------------------
                                        Leon O. Moulder, Jr.
                                        Executive Vice President


                                 Per:     /s/ William C. Brown
                                        ----------------------------------------
                                        William C. Brown
                                        Chief Financial Officer and Secretary