Exhibit 4.10

                               WARRANT CERTIFICATE

                               YM BIOSCIENCES INC.

                  (Incorporated under the laws of Nova Scotia)

WARRANT              ----------    -------------------------------------WARRANTS
CERTIFICATE NO.                    entitling the holder to acquire, subject to
                                   adjustment, one Common Share for each Warrant
                                   represented hereby

CUSIP No.            984238113

THIS IS TO CERTIFY THAT ___________________ (hereinafter referred to as the
"HOLDER") is the registered holder of the number of warrants ("WARRANTS") to
receive common shares ("SHARES") of YM BIOSCIENCES INC. (the "CORPORATION") as
set forth in this certificate ("WARRANT CERTIFICATE"). Each whole Warrant
represented hereby entitles the holder to purchase one fully paid and
non-assessable Share of the Corporation, without nominal or par value, as such
shares were constituted on [SEPTEMBER 30], 2004, in the manner and subject to
the restrictions and adjustments set forth herein, at any time and from time to
time until 5:00 p.m. (Toronto Time) (the "TIME OF EXPIRY") on [SEPTEMBER 30],
2007 (the "EXPIRY DATE") at a price of Cdn. $3.75 per share, subject to
adjustment in accordance with the Indenture (as defined below).

The right to acquire Shares hereunder may only be exercised by the holder within
the time set forth above by:

            (a)   duly completing and executing the Exercise Form attached
                  hereto and also available upon request from CIBC Mellon Trust
                  Company (the "Trustee") at the principal office of the Trustee
                  in the City of Toronto;

            (b)   surrendering this Warrant Certificate and the duly completed
                  and executed Exercise Form to the Trustee at the principal
                  office of the Trustee in the City of Toronto; and

            (c)   remitting a certified cheque in lawful money of Canada,
                  payable to or to the order of the Trustee at par where this
                  Warrant Certificate is so surrendered, for the aggregate
                  purchase price of the Shares so subscribed for.

This Warrant Certificate shall be deemed to be surrendered only upon personal
delivery hereof or, if sent by mail or other means of transmission, upon actual
receipt thereof by the Trustee at the office referred to above.

Upon surrender of these Warrants, the person or persons in whose name or names
the Shares issuable upon exercise of the Warrants are to be issued shall be
deemed for all purposes (except as provided in the Indenture hereinafter
referred to) to be the holder or holders of record of such Shares and the
Corporation has covenanted that it will (subject to the provisions of the
Indenture) cause a certificate or certificates representing such Shares to be
delivered or mailed to the person or persons at the address or addresses
specified in the Exercise Form within five Business Days.

The registered holder of this Warrant Certificate may acquire any lesser number
of Shares than the number of Shares which may be acquired for the Warrants
represented by this Warrant Certificate. In such event, the holder shall be
entitled to receive without charge a new Warrant Certificate for the balance of
the Shares which may be acquired. No fractional Shares will be issued.

<PAGE>

                                      -2-

The Warrants represented by this certificate are issued under and pursuant to a
warrant indenture (herein referred to as the "INDENTURE") made as of [SEPTEMBER
30], 2004 between the Corporation and the Trustee. Reference is made to the
Indenture and any instruments supplemental thereto for a full description of the
rights of the holders of the Warrants and the terms and conditions upon which
the Warrants are, or are to be, issued and held, with the same effect as if the
provisions of the Indenture and all instruments supplemental thereto were set
forth herein. By acceptance hereof, the holder assents to all provisions of the
Indenture. In the event of a conflict between the provisions of the Warrant
Certificate and the Indenture, the provisions of the Indenture shall govern.
Capitalized terms used in the Indenture have the meaning herein as therein,
unless otherwise defined.

In the event of any alteration of the Shares, including any subdivision,
consolidation or reclassification, and in the event of any form of
reorganization of the Corporation including any amalgamation, merger or
arrangement, the holders of Warrants shall, upon exercise of the Warrants
following the occurrence of any of those events, be entitled to receive the same
number and kind of securities that they would have been entitled to receive had
they exercised their Warrants immediately prior to the occurrence of those
events, subject to the provisions of the Indenture.

The registered holder of this Warrant Certificate may, at any time prior to the
Time of Expiry, upon surrender hereof to the Trustee at its principal office in
the City of Toronto, exchange this Warrant Certificate for other certificates
entitling the holder to acquire, in the aggregate, the same number of Shares as
may be acquired under this Warrant Certificate.

The holding of the Warrants evidenced by this Warrant Certificate shall not
constitute the holder hereof a shareholder of the Corporation or entitle the
holder to any right or interest in respect thereof except as expressly provided
in the Indenture or in this Warrant Certificate.

The Indenture provides that all holders of Warrants shall be bound by any
resolution passed at a meeting of the holders held in accordance with the
provisions of the Indenture and resolutions signed by the holders of Warrants
entitled to acquire a specified majority of the Shares which may be acquired
pursuant to all then outstanding Warrants.

The Warrants evidenced by this Warrant Certificate may be transferred on the
register kept at the offices of the Trustee by the registered holder hereof or
its legal representatives or its attorney duly appointed by the transfer form
attached hereto or by another instrument in writing in form and execution
satisfactory to the Trustee, only upon compliance with the conditions prescribed
in the Indenture and upon compliance with such reasonable requirements as the
Trustee may prescribe.

This Warrant Certificate shall not be valid for any purpose whatever unless and
until it has been certified by or on behalf of the Trustee.

<PAGE>

                                      -3-

Time shall be of the essence hereof. This Warrant Certificate shall be governed
by and construed in accordance with the laws of the province of Ontario and the
federal laws of Canada applicable therein and shall be treated in all respects
as an Ontario contract.

IN WITNESS WHEREOF the Corporation has caused this Warrant Certificate to be
signed by its duly authorized officers as of the 30th day of September, 2004.

                                      YM BIOSCIENCES INC.

                                      Per:
                                           ------------------------------------


Countersigned by:

CIBC MELLON TRUST COMPANY

Trustee

By:
    ---------------------------------------

<PAGE>

                                                                    Exhibit 4.10

                                   APPENDIX 1

                              TRANSFER OF WARRANTS

FOR VALUE RECEIVED, the undersigned hereby sells, assigns and transfers to
________________________________________(name)

--------------------------------------------------------------------------------
---------------------------, (address) ______________________ (number of
warrants) Warrants of YM BIOSCIENCES INC. registered in the name of the
undersigned on the records of CIBC MELLON TRUST COMPANY represented by the
Warrant Certificate attached and irrevocably appoints __________________ the
attorney of the undersigned to transfer the said securities on the books or
register with full power of substitution and confirms that the transfer is made
in compliance with all applicable securities legislation and requirements of
regulatory authorities.

Such certificates (please check one):

(a)                          should be sent by first class mail to the following
                             address
      --------------

                             ---------------------------------------------------

                             ---------------------------------------------------


(b)                          should be held for pick up at the office of the
                             Trustee at which this Warrant Certificate is
                             deposited.
      --------------

If less than all the Warrants represented by this Warrant Certificate are being
transferred, the Warrant Certificate representing those Warrants not transferred
will be registered in the name appearing on the face of this Warrant Certificate
and such certificates (please check one):

(a)                          should be sent by first class mail to the following
                             address
      --------------

                             ---------------------------------------------------

                             ---------------------------------------------------

(b)                          should be held for pick up at the office of the
                             Trustee at which this Warrant Certificate is
                             deposited.
      --------------


            DATED the _____ day of _________________________, 200___.


------------------------------------        ------------------------------------
Signature Guaranteed                        (Signature of Warrantholder)

<PAGE>

                                      -2-

INSTRUCTIONS:

1.    The signature of the Warrantholder must be the signature of the person
      appearing on the face of this Warrant Certificate and must be guaranteed
      by a Canadian Schedule 1 chartered bank, a major trust company in Canada,
      or a member of the Securities Transfer Association medallion program
      (Stamp) (SEMP) (MSP). The Guarantor must affix a stamp bearing the actual
      words "Signature Guaranteed".

      PLEASE NOTE - SIGNATURE GUARANTEES ARE NOT ACCEPTED FROM TREASURY BRANCHES
      OR CREDIT UNIONS UNLESS THEY ARE MEMBERS OF THE STAMP MEDALLION PROGRAM.

      PLEASE NOTE IN USA, SIGNATURE GUARANTEES MUST BE DONE BY MEMBERS OF THE
      "MEDALLION SIGNATURE GUARANTEE PROGRAM" ONLY.

2.    If the Transfer Form is signed by a trustee, executor, administrator,
      curator, guardian, attorney, officer of a corporation or any person acting
      in a judiciary or representative capacity, the certificate must be
      accompanied by evidence of authority to sign satisfactory to the Trustee
      and the Corporation.

3.    THE WARRANTS SHALL ONLY BE TRANSFERABLE IN ACCORDANCE WITH APPLICABLE
      LAWS.

4.    The Warrants and the Shares issuable upon exercise thereof have not been
      registered under the United States Securities Act of 1933, as amended (the
      "U.S. SECURITIES ACT"), or the securities laws of any state of the United
      States, and may not be transferred in the United States or to a U.S.
      Person unless the Warrants and the Shares have been registered under the
      U.S. Securities Act and the securities laws of all applicable states of
      the United States or an exemption from such registration requirements is
      available. In connection with any transfer of Warrants, the holder will be
      required to provide to the Trustee and the Corporation an opinion of
      counsel, or other evidence, in form reasonably satisfactory to the
      Corporation, to the effect that such transfer of Warrants does not require
      registration under the U.S. Securities Act or any applicable state laws
      and regulations governing the offer and sale of securities.

                              OFFICE OF THE TRUSTEE
                            CIBC MELLON TRUST COMPANY

        If by hand or courier:                             If by mail:

       CIBC Mellon Trust Company                    CIBC Mellon Trust Company
      ATTENTION: Special Projects                  ATTENTION: Special Projects
          Commerce Court West                             P.O. Box 1036
            199 Bay Street                        Adelaide Street Postal Station
           Securities Level                              Toronto, Ontario
           Toronto, Ontario                                  M5C 2K4
                M5L 1G9

<PAGE>

                                                                    Exhibit 4.10

                                   APPENDIX 2

                                  EXERCISE FORM

TO:         YM BIOSCIENCES INC.

AND TO:     CIBC MELLON TRUST COMPANY

      o     The undersigned hereby exercises the right to acquire and hereby
            subscribes for and agrees to take up_______________ Shares (the
            "SHARES") of YM BIOSCIENCES INC. as constituted on September 30,
            2004 (or such number of other securities or property to which such
            Warrants entitle the undersigned in lieu thereof or in addition
            thereto under the provisions of the Indenture referred to in the
            accompanying Warrant Certificate) in accordance with and subject to
            the provisions of such Indenture and delivers herewith as payment of
            the exercise price of Cdn. $3.75 per Share until the Expiry Time on
            the Expiry Date a certified cheque in lawful money of Canada payable
            to YM BIOSCIENCES Inc. in the amount of $_______________ (the
            "EXERCISE PRICE").

      o     All terms capitalized herein and not otherwise defined shall have
            the same meaning as are ascribed to them in the Warrant Indenture
            dated as of September 30, 2004 entered into between the Corporation
            and CIBC Mellon Trust Company.

      o     The Shares (or other securities or property) are to be issued as
            follows:

            Name:
                  --------------------------------------------------------------
                          (print clearly)


            Address in full:
                             ---------------------------------------------------

            --------------------------------------------------------------------

            Social Insurance Number
                                       -----------------------------------------

            Number of Shares
                                       -----------------------------------------

            NOTES:

            1.    If further nominees intended, please attach (and initial)
                  schedule giving these particulars.

      o     Such securities (please check one):

            o     __________should be sent by first class mail to the following
                  address:

<PAGE>

                                      -2-

            --------------------------------------------------------------------

            --------------------------------------------------------------------

                                       OR

            o     should be held for pick up at the office of the Trustee at
                  which this Warrant Certificate is deposited.

      o     If the number of Warrants exercised are less than the number of
            Warrants represented hereby, the undersigned requests that the new
            Warrant Certificate representing the balance of the Warrants be
            registered in the name of

          whose address is

            --------------------------------------------------------------------

--------------------------------------------------------------------------------

Such securities (please check one):

            o     __________should be sent by first class mail to the following
                  address:

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

                                       OR

            o     __________should be held for pick up at the office of the
                  Trustee at which this Warrant Certificate is deposited.

            In the absence of instructions to the contrary, the securities or
            other property will be issued in the name of or to the holder hereof
            and will be sent by first class mail to the last address of the
            holder appearing on the register maintained for the Warrants.

      o     The undersigned hereby represents and warrants to the Corporation
            that the undersigned (check one):

            o     _______________is not a U.S. Person and the Warrant is not
                  being exercised within the United States or on behalf of, or
                  for the account or benefit of, a U.S. Person or a person in
                  the United States;

            o     _______________was an original subscriber for Warrants or a
                  transferee pursuant to section 2.10(b) of the Warrant
                  Indenture between the Corporation and the Trustee, who was a
                  U.S. Person at the time of the acquisition of such Warrants
                  and the representations and warranties made by such person in
                  connection with the acquisition of such Warrants remain true
                  and correct on the date of exercise; or

<PAGE>
                                      -3-

            o     _______________has delivered herewith to the Trustee and the
                  Corporation a written opinion of counsel or other evidence
                  satisfactory to the Corporation to the effect that the Common
                  Shares have been registered under the U.S. Securities Act and
                  applicable state securities laws or are exempt from
                  registration thereunder.

If the foregoing correctly sets forth your understanding, please indicate your
acceptance thereof by signing and returning the enclosed duplicate of this
Exercise Form. This Exercise Form may be signed in counterpart, which
counterparts together shall be deemed to constitute one valid and binding
agreement and delivery of counterparts may be effected by means of facsimile
transmission.

DATED this ____ day of __________________________, 200___.

--------------------------------       -----------------------------------------
Signature Guaranteed                   (Signature of Warrantholder)


                                       -----------------------------------------
                                       Print full name


                                       -----------------------------------------


                                       -----------------------------------------
                                       Print full address

<PAGE>
                                      -4-

INSTRUCTIONS:

      For the purposes of paragraph (f) above, the following words and phrases
      have the following meanings:

            "United States" and "U.S. Person" have the meaning given to such
            terms under Regulation S of the U.S. Securities Act. For purposes of
            Regulation S, "United States" means the United States of America,
            its territories and possessions, any statue of the United States and
            the District of Columbia. "U.S. Person" includes, with certain
            exceptions, (i) any natural person resident in the United States;
            (ii) any partnership or corporation organized or incorporated under
            the laws of the United States; (iii) any estate of which any
            executor or administrator is a U.S. Person; (iv) any trust of which
            any trustee is a U.S. Person; (v) any agency or branch of a foreign
            entity located in the United States; (vi) any non-discretionary
            account or similar account (other than an estate or trust) held by a
            dealer or other fiduciary for the benefit or account of a U.S.
            Person; (vii) any discretionary account or similar account (other
            than an estate or trust) held by a dealer or other fiduciary
            organized, incorporated or (if an individual) resident in the United
            States; and (viii) any partnership or corporation if (a) organized
            or incorporated under the laws of any jurisdiction other than the
            United States and (b) formed by a U.S. Person principally for the
            purposes of investing in securities not registered under the U.S.
            Securities Act; and

            "U.S. Securities Act" means the United States Securities Act of
            1933, as amended.

      o     The registered holder may exercise its right to receive Shares by
            completing this form and surrendering this form and the Warrant
            Certificate representing the Warrants being exercised to CIBC MELLON
            TRUST COMPANY at its principal office in Toronto. Certificates for
            Shares will be delivered or mailed within five business days after
            the exercise of the Warrants.

      o     If the Exercise Form indicates that Shares are to be issued to a
            person or persons other than the registered holder of the
            Certificate, the signature of such holder of the Exercise Form must
            be guaranteed by an authorized officer of a Canadian Schedule 1
            chartered bank, a major trust company in Canada, an investment
            dealer who is a member of a recognized stock exchange or a member of
            the Securities Transfer Association medallion program (Stamp) (SEMP)
            (MSP). The Guarantor must affix a stamp bearing the actual words
            "SIGNATURE GUARANTEED".

            *Please note - Signature Guarantees are not accepted from Treasury
            Branches or Credit Unions unless they are members of the Stamp
            Medallion Program.

            **Please note - in the U.S.A., signature guarantees must be done by
            members of the "Medallion Signature Guarantee Program" only.

      o     If the Exercise Form is signed by a trustee, executor,
            administrator, curator, guardian, attorney, officer of a corporation
            or any person acting in a fiduciary or representative capacity, the
            certificate must be accompanied by evidence of authority to sign
            satisfactory to the Trustee and the Corporation.

                              OFFICE OF THE TRUSTEE
                            CIBC MELLON TRUST COMPANY

        If by hand or courier:                             If by mail:

       CIBC Mellon Trust Company                    CIBC Mellon Trust Company
      ATTENTION: Special Projects                  ATTENTION: Special Projects
          Commerce Court West                             P.O. Box 1036
            199 Bay Street                        Adelaide Street Postal Station
           Securities Level                              Toronto, Ontario
           Toronto, Ontario                                  M5C 2K4
                M5L 1G9

<PAGE>

                                                                    Exhibit 4.10

                                   APPENDIX 3

                    FORM OF DECLARATION FOR REMOVAL OF LEGEND

TO:     CIBC Mellon Trust Company
        as transfer agent and registrar
        for the common shares and
        warrant agent for the warrants of
        YM BioSciences Inc.

The undersigned:

o     acknowledges that the sale of the securities of YM BioSciences Inc. to
      which this declaration relates is being made in reliance on Rule 904 of
      Regulation S ("Regulation S") under the United States Securities Act of
      1933, as amended (the "Securities Act"), and

o     certifies that:

      1.    it is not an "affiliate" (as defined in Rule 405 under the
            Securities Act) of YM BioSciences Inc.,

      2.    the offer of such securities was not made to a person in the United
            States and either (A) at the time the buy order was originated, the
            buyer was outside the United States, or the seller and any person
            acting on its behalf reasonably believe that the buyer was outside
            the United States, or (B) the transaction was executed on or through
            the facilities of the Toronto Stock Exchange, and neither the seller
            nor any person acting on its behalf knows that the transaction has
            been prearranged with a buyer in the United States,

      3.    neither the seller nor any affiliate of the seller nor any person
            acting on any of their behalf has engaged or will engage in any
            "directed selling efforts" (as such term is defined in Regulation S)
            in the United States in connection with the offer and sale of such
            securities,

      4.    the sale is bona fide and not for the purpose of "washing off" the
            resale restrictions imposed because the securities are "restricted
            securities" (as that term is defined in Rule 144(a)(3) under the
            Securities Act),

      5.    the seller does not intend to replace the securities sold in
            reliance on Rule 904 of Regulation S with fungible unrestricted
            securities, and

      6.    the contemplated sale is not a transaction, or part of a series of
            transactions which, although in technical compliance with Regulation
            S, is part of a plan or scheme to evade the registration provisions
            of the Securities Act.

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