***4***
***th***

***day of December, 2007***

|   | ***1411029                  ONTARIO LIMITED***                   |   |                                |
|--------|------------------------------------------------------------------|--------|-------------------------------------|
|   | (hereinafter                  called the “Landlord”) |   |                                |
|   |                                                             |   |                                |
|   |                                                             |   | OF                  THE FIRST PART  |
|   |                                                             |   |                                |
|   | -                  and -                                         |   |
|   |                                                             |   |                                |
|   | ***YM                  BIOSCIENCES INC.***                       |   |                                |
|   | (hereinafter                  called the “Tenant”)   |   |                                |
|   |                                                             |   |                                |
|   |                                                             |   | OF                  THE SECOND PART |

***Building      11, Suite 400***
***5045      Orbitor Drive***

***The      Landlord acquired the Building from Griffin Development Corporation and PR      Land      Holdings Ltd. and is now the Landlord under the      Lease.***

*And      by a      lease amending and extension agreement dated January 15, 2003, betweenLandlord      and Tenant, the Initial Term was extended for a further period of five (5)      yearscommencing      on February 1, 2003 and expiring on January 31, 2008 (the “First ExtensionTerm”).*

*And      by a lease amending and extension agreement dated October 10, 2007, the parties      agreed to expand the premises to include additional premises adjacent thereto      **Building 11, Suite 401** comprising of approximately 1,770 square      feet (the “Additional Premises”) which thereafter formed part of the Leased      Premises as set forth in the Lease, consisting of **a total Rentable Area      of 7,070 square feet** (collectively known as the“Premises”).*

***The      parties have agreed to further amend and extend the Lease as set out in this      Agreement.***

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***Item      8 of the Term Sheet to the Lease is hereby amended by inserting the following:***
*“Year      I of the Second Extension Term – **$10.25** per square foot of      the Rentable Area per annum; Year 2 of the Second Extension Term –**$10.50**per square foot of the Rentable Area per annum; Year 3      of the Second Extension Term – **$10.75**per square foot of the      Rentable Area per annum; Year 4 of the Second Extension Term –**$11.00** per square foot of the Rentable Area per annum; Year 5      of the Second Extension Term – **$11.25** per square foot of the      Rentable Area per annum”.*

| Landlord:                                                       |
|-----------------------------------------------------------------|
| ***1411029 ONTARIO LIMITED***                         |
|                                                            |   |
| per:                                                            | [Illegible] | c/s |
|                                                            | Print                Name: |
|                                                            | Print                Title: |
|                                                            |   |
| I/We                have the authority to bind the corporation. |
|                                                            |   |
| Tenant:                                                         |
| ***YM                BIOSCIENCES INC.***                        |
|                                                            |   |
| per:                                                            | [Illegible] | c/s |
|                                                            | Print                Name : [Illegible] |
|                                                            | Print                Title: [Illegible] |

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