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TRILLIUM THERAPEUTICS INC.

DEFERRED SHARE UNIT PLANFOR DIRECTORS AND
EXECUTIVE OFFICERS(CASH SETTLED)Effective as of November
9, 2016

PART l - GENERAL PROVISIONS

Purpose

1.1        The purpose of
this Plan is to provide an alternative form of compensation to satisfy annual
and special bonuses payable to Directors and Executive Officers and to satisfy
fees that may be payable to Directors for acting as directors of the Company.
This form of compensation promotes a greater alignment of interests amongst
Directors and Executive Officers and the Companys shareholders.

Definitions

1.2        In this Plan,

Annual Board Retainer means the annual retainer paid by
the Company to a Director, but does not include Chair Fees, Committee Fees and
Meeting Fees;

Applicable Withholding Taxes means any and all taxes and
other source deductions or other amounts which the Company is required by law to
withhold from any amounts paid or credited to the account of an Eligible Person
under this Plan;

Awarded Amounthas the meaning set forth in Section 2.1;

Board means the Board of Directors of the Company;

Chair means the chair of the Board;

Chair Fees means the fees or retainers, other than
Meeting Fees, the Annual Board Retainer and Committee Fees, paid by the Company
to a Director for service as the Chair and as chairperson of a committee of the
Board;

Change of Controlmeans:

| | (a) | any transaction at any time and by whatever means
      pursuant to which (A) the Company goes out of existence by any means,
      except for any corporate transaction or reorganization in which the
      proportionate voting power among holders of securities of the entity
      resulting from such corporate transaction or reorganization is
      substantially the same as the proportionate voting power of such holders
      of Company voting securities immediately prior to such corporate
      transaction or reorganization or (B) any person or any group of two or
      more persons acting jointly or in concert (other than the Company, a
      wholly-owned Subsidiary (as defined in the Securities Act(Ontario)) of the Company, an employee benefit plan of the Company or
      of any of its wholly-owned Subsidiaries, including the trustee of any such
      plan acting as trustee) hereafter acquires the direct or indirect beneficial ownership
      (as defined by the Business Corporations Act(Ontario)) of, or
      acquires the right to exercise control or direction over, securities of
      the Company representing 50% or more of the Companys then issued and
      outstanding securities in any manner whatsoever, including, without
      limitation, as a result of a take-over bid, an exchange of securities, an
      amalgamation of the Company with any other entity, an arrangement, a
      capital reorganization or any other business combination or
      reorganization;
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| | (b) | the sale, assignment or other transfer of all or
      substantially all of the assets of the Company to a person other than a
      wholly-owned Subsidiary of the Company;                                                                                                                                                                                                                           
| | --- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| |     |                                                                                                                                                                                                                                                                                                                                                                                                        
| | (c) | the dissolution or liquidation of the Company except in
      connection with the distribution of assets of the Company to one or more
      persons which were wholly-owned subsidiaries of the Company immediately
      prior to such event;                                                                                                                                                        
| |     |                                                                                                                                                                                                                                                                                                                                                                                                        
| | (d) | the occurrence of a transaction requiring approval of the
      Companys shareholders whereby the Company is acquired through
      consolidation, merger, exchange of securities, purchase of assets,
      amalgamation, arrangement or otherwise by any other person (other than a
      short form amalgamation or exchange of securities with a wholly-owned
      subsidiary of the Company); or
| |     |                                                                                                                                                                                                                                                                                                                                                                                                        
| | (e) | the Board passes a resolution to the effect that an event
      set forth in (a), (b), (c) or (d) above has
occurred;                                                                                                                                                                                                                                                                                  

Codemeans the United States Internal Revenue Code of
1986, as amended;

Committee means the Compensation Committee of the Board,
or any other persons designated by the Board to perform the duties contemplated
herein;

Committee Fees means the fees or retainers, other than
Meeting Fees, the Annual Board Retainer and Chair Fees, paid by the Company to a
Director for service on a committee of the Board;

Companymeans Trillium Therapeutics Inc. or any
successor thereof;

Deferred Share Unit means a right granted by the Company
to an Eligible Person to receive a cash payment, evidenced by way of
book-keeping entry in the books of the Company, equal to the Fair Market Value
of a Share as of the applicable determination date;

Director means any Director of the Company, or a
subsidiary of the Company, appointed and approved by the Board or the
shareholders;

Director Fees means the aggregate total of the Annual
Board Retainer, Chair Fees, Committee Fees, Meeting Fees and any other fees
payable to a Director;

Eligible Person means any person who is a Director or
Executive Officer;

Executive Officer means the Chief Executive Officer,
President, Chief Financial Officer and any senior officer of the Company, or any
subsidiary of the Company, or any persons acting in any such capacity on behalf
of the Company or subsidiary of the Company;

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Fair Market Value means the five-day volume weighted
average trading price, being the VWAP (as the term VWAP is defined in the TSX
Company Manual), as at, and including, the relevant determination date or such
other applicable date referenced herein provided that such date is a business
day and if it is not then calculated as at and including the last business day
which preceded such applicable date referenced herein, except that if the Shares
are not listed on the TSX, the Fair Market Value will be the value established
by the Board based on the five-day average closing price per Share on any other
public exchange on which the Shares are listed calculated as at, and including,
the relevant determination date or such other applicable date referenced herein
provided that such date is a business day and if it is not then calculated as at
and including the last business day which proceeded such applicable date
referenced herein, or if the Shares are not listed on any public exchange, by
the Board based on its determination of the fair value of a Share;

Filing Date means the date on which a Redemption Notice
is filed with the Company by an Eligible Person following the occurrence of
Terminated Service;

Insidermeans an insider as defined in Section 613 of
the TSX Company Manual;

Meeting Feesmeans the fees or retainers, other than the
Annual Board Retainer, Chair Fees, and Committee Fees, paid by the Company to a
Director for attending meetings of the Board or any committee of the Board;

Plan means this Deferred Share Unit Plan, as amended
from time to time;

Redemption Notice means a notice filed (or deemed to be
filed) by an Eligible Person with the Company following the occurrence of
Terminated Service to trigger the redemption of Deferred Share Units in
accordance with Section 3.2, which notice shall be in the form prescribed from
time to time by the Company;

Section 409A means Section 409A of the Code and any
applicable United States Treasury Regulations and other binding regulatory
guidance thereunder;

Separation from Serviceof a US Taxpayer means the date
the US Taxpayer incurs a separation from service with the Company within the
meaning of U.S. Treas. Regs. § 1.409A -1(h);

Sharemeans a common share in the capital of the
Company;

Specified Employee means a US Taxpayer who meets the
definition of specified employee, as defined in Section 409A(a)(2)(B)(i) of
the Code;

Tax Act means the Income Tax Act (Canada);

Terminated Service means that the Eligible Person has
ceased to be a Director and/or Executive Officer, as applicable, including
through the termination, voluntary resignation, retirement or death of such
Eligible Person;

Total Compensation for a particular Eligible Person
means the aggregate of:

| | (a) | the discretionary annual bonus determined by the Board
      for which Directors or Executive Officers are
eligible;
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| | (b) | a bonus, that is not an annual bonus, that may be awarded
      to a Director or Executive Officer at the discretion of the Board;
    and
| | --- | ------------------------------------------------------------------------------------------------------------------------------------------
| |     |                                                                                                                                           
| | (c) | Director Fees.                                                                                                                            

TSX means the Toronto Stock Exchange; and

US Taxpayer means an Eligible Person whose compensation
from the Company is subject to Section 409A.

Effective Date

1.3        This Plan will
become effective as of November 9, 2016.

Administration

1.4        The Board will,
in its sole and absolute discretion, but taking into account relevant corporate,
securities and tax laws:

| | (a) | interpret and administer this Plan;                                                                                   
| | --- | ----------------------------------------------------------------------------------------------------------------------
| |     |                                                                                                                       
| | (b) | establish, amend and rescind any rules and regulations
      relating to this Plan; and                               
| |     |                                                                                                                       
| | (c) | make any other determinations that the Board deems
      necessary or desirable for the administration of this
  Plan.

The Board may correct any defect or any omission or reconcile
any inconsistency in this Plan in the manner and to the extent the Board deems,
in its sole and absolute discretion, necessary or desirable. Any decision of the
Board in the interpretation and administration of this Plan will be final,
conclusive and binding on all parties concerned. All expenses of administration
of this Plan will be borne by the Company.

Delegation

1.5        The Board may, to
the extent permitted by law, delegate any of its responsibilities under this
Plan and powers related thereto (including, without limiting the generality of
the foregoing, those referred to under Section 1.4) to the Committee or to one
or more officers of the Company and all actions taken and decisions made by the
Committee or by such officers in this regard will be final, conclusive and
binding on all parties concerned, including, but not limited to, the Company,
the Eligible Person, and their legal representatives.

Limitation of Liability

1.6        None of the
Company, the Board, the Committee nor any other person to whom authority is
delegated under Section 1.5 of this Plan shall be liable for any action,
omission or determination made in good faith with respect to this Plan.

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PART 2 - AWARDS UNDER THIS PLAN

Determination of Deferred Share Units

2.1        The Board will,
in its sole and absolute discretion, decide at the time of declaring or awarding
any Total Compensation to any Eligible Person the amount (the "Awarded
Amount") of the Total Compensation that will be satisfied in the form of
Deferred Share Units.

2.2        The Board shall
also determine, in connection with each grant, the effective date thereof, the
terms and conditions of vesting, and such other terms and conditions which the
Board considers appropriate to the award in question, and which terms and
conditions need not be identical as between any two awards, whether or not
contemporaneous.

Issue of Deferred Share Units

2.3        The number of
Deferred Share Units (including fractional Deferred Share Units, computed to
three digits) to be credited to an Eligible Person for services will be
determined by dividing the Awarded Amount by the Fair Market Value as at the
last trading day before the date the Awarded Amount is declared by the Board.

Dividend Equivalents

2.4        On any date on
which a cash dividend is paid on Shares, an Eligible Persons account will be
credited with the number of Deferred Share Units (including fractional Deferred
Share Units, computed to three digits) calculated by:

| | (a) | multiplying the amount of the dividend per Share by the
      aggregate number of Deferred Share Units that were credited to the
      Eligible Persons account as of the record date for payment of the
      dividend; and
| | --- | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| |     |                                                                                                                                                                                                                              
| | (b) | dividing the amount obtained in Section 2.4(a) by the
      Fair Market Value on the date on which the dividend is
  paid.                                                                                                   

Eligible Persons Account

2.5        The Company shall
maintain or cause to be maintained in its records an account for each Eligible
Person recording at all times the number of Deferred Share Units credited to the
Eligible Persons account. Upon payment in satisfaction of Deferred Share Units
in accordance with Part 3 of the Plan, the Eligible Persons entitlement to
receive any and all amounts in respect of Deferred Share Units so paid shall be
fully discharged and satisfied and such Deferred Share Units shall be cancelled
and thereupon deleted from the account of such Eligible Person.

2.6        A written
confirmation of the balance in each Eligible Persons account will be sent by
the Company to the Eligible Person upon request of the Eligible Person.

Adjustments and Reorganizations

2.7        In the event of
any dividend paid in shares, share subdivision, combination or exchange of
shares, merger, consolidation, spin-off or other distribution of Company assets
to shareholders, or any other change in the capital of the Company affecting
Shares, the Board, in its sole and absolute discretion, will make, with respect
to the number of Deferred Share Units outstanding under this Plan, any proportionate adjustments as
it considers appropriate to reflect that change.

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Change of Control

2.8        In the event that
an Eligible Person has Terminated Service (other than as a result of termination
for cause or death) within 24 months following a Change of Control, all Deferred
Share Units credited to each Eligible Persons account shall immediately vest in
full.

PART 3 - PAYMENT OF BENEFITS

Redemption of Deferred Share Units

3.1        Subject to the
provisions of this Plan, a Deferred Share Unit held by an Eligible Person shall
be redeemed by the Company upon Terminated Service in accordance with Section
3.2 or Section 3.3, as applicable.

Payment of Benefits

3.2        Any Deferred
Share Unit awarded pursuant to this Plan shall be settled in cash only as
follows:

| | (a) | An Eligible Person who has Terminated Service may elect
      the date on which the Deferred Share Units held by that Eligible Person
      shall be redeemed by the Company by filing with the Chief Financial
      Officer of the Company a Redemption Notice on or before December 15 of the
      first calendar year commencing after the date on which the Eligible Person
      has Terminated Service. If the Eligible Person fails to file such
      Redemption Notice on or before that December 15, the Eligible Person shall
      be deemed to have filed the Redemption Notice on that December 15. The
      date on which a Redemption Notice is filed, or deemed to be filed, shall
      hereinafter be referred to as the Filing Date. The Company may
      defer the Filing Date to any other date if such deferral is, in the sole
      opinion of the Company, desirable to ensure compliance with Section
      4.6.
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| |     |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  
| | (b) | The cash payment to which an Eligible Person shall be
      entitled in settlement of a Deferred Share Unit shall be equal in amount
      to the product that results by multiplying: (x) the number of Deferred
      Share Units credited to the Eligible Person as at the date on which the
      Eligible Person has Terminated Service, by (y) the Fair Market Value of a
      Share as of the Filing Date, net of Applicable Withholding
Taxes.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
| |     |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  
| | (c) | A cash payment pursuant to this Section 3.2 shall be made
      to the Eligible Person as soon as reasonably possible following the Filing
      Date, but in any event not later than the date that is 60 days following
      the Filing Date; provided, however, that in no event will such payment be
      made later than December 31 of the first calendar year commencing after
      the Eligible Person has Terminated Service. Upon payment of such amount,
      the Deferred Share Units shall be cancelled and such Eligible Person shall
      have no further rights under the Plan.                                                                                                                                                                                                                                                                                                                                             

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US Taxpayers

3.3        Notwithstanding
the foregoing provisions of Section 3.2, if an Eligible Person is a US Taxpayer,
then the following rules shall apply relating to the redemption of Deferred
Share Units:

| | (a) | Deferred Share Units which become redeemable under
      Section 3.1 shall be redeemed only upon a Separation from Service;
    and                                                                                                                                                                                                                                                                 
| | --- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| |     |                                                                                                                                                                                                                                                                                                                                                                                                     
| | (b) | the redemption date shall be any date determined by the
      Company to occur as soon as reasonably possible (but not later than 60
      days) after the Separation from Service, except that if the US Taxpayer is
      determined to be a Specified Employee, the redemption date shall be the
      first day of the seventh month after the Separation from Service of the US
      Taxpayer.

Death

3.4        In the event of
the death of an Eligible Person prior to the settlement of the Deferred Share
Units credited to his her own account:

| | (a) | all unvested Deferred Share Units shall automatically
      vest in full; and                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       
| | --- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| |     |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
| | (b) | the Company will, as soon as reasonably practicable and
      any event not later than 60 days following the Eligible Persons death,
      cause to be delivered to the legal representatives of the Eligible Person,
      the cash payment such Eligible Person would otherwise have been entitled
      to if the Eligible Person had Terminated Service (which cash payment
      shall, for the avoidance of doubt, be determined in accordance with
      Section 3.2(b), with the reference date for the purposes of both
      subclauses (x) and (y) of that Section being the date of the Eligible
      Persons death).

PART 4 - GENERAL

Tax Consequences

4.1        It is the
responsibility of the Eligible Person to complete and file any tax returns which
may be required under any applicable tax laws within the periods specified in
those laws as a result of the Eligible Persons participation in this Plan. The
Company shall not be responsible for any tax consequences to the Eligible Person
as a result of the Eligible Persons participation in this Plan. The Eligible
Person shall remain responsible at all times for paying any federal, provincial,
state, local and foreign income or employment tax due with respect to any
Deferred Share Units awarded to the Eligible Person, and the Company shall not
be liable for any interest or penalty that an Eligible Person incurs by failing
to make timely payments of tax.

Withholding Requirements

4.2        Prior to the
delivery of any cash pursuant to this Plan, the Company shall be required, and
shall have the power and the right, to deduct or withhold from any payment to or
for the benefit of an Eligible Person any amount required to comply with the
applicable provisions of any federal, provincial, state, local or foreign law
relating to the withholding of tax or the making of any other source deductions,
including on the amount, if any, included in the income of an Eligible Person and may adopt and apply such rules and
regulations that in its opinion will ensure that the Company will be able to so
comply.

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Tax Status

4.3        With respect to
any Eligible Participant that is not a US Taxpayer, it is intended that at all
times this Plan shall be administered or operated such that it meets the
conditions of Regulation 6801(d) enacted pursuant to the Tax Act, or any
successor provisions thereto (Regulation 6801(d)).

Non-Transferability

4.4        Deferred Share
Units and all other rights, benefits or interests in this Plan are
non-transferable and may not be pledged or assigned or encumbered in any way and
are not subject to attachment or garnishment, except that if the Eligible Person
dies, the legal representatives of the Eligible Person will be entitled to
receive the amount of any payment otherwise payable to the Eligible Person
hereunder in accordance with the provisions hereof.

No Right to Service

4.5        Neither
participation in this Plan nor any action under this Plan will be construed to
give any Eligible Person a right to be retained in the service of the Company or
a right to receive any benefits not expressly provided in this Plan.

Compliance with Applicable Laws

4.6        Any obligation of
the Company under this Plan is subject to compliance with all applicable laws,
regulations, rules, orders of governmental or regulatory authorities, the
requirements of the applicable stock exchange(s) on which the Shares trade and
any applicable policies of the Company relating to insider trading or "blackout"
periods in effect from time to time. Each Eligible Person shall comply with all
such laws, regulations, rules, orders and requirements, and shall furnish the
Company with any and all information and undertakings as may be required to
ensure compliance therewith.

Successors and Assigns

4.7        This Plan will
enure to the benefit of and be binding upon all successors and assigns of the
Company and any Eligible Person, including the estate of such Participant and
the executor, liquidator, administrator or trustee of such estate, or any
receiver or trustee in bankruptcy or representative of the Eligible Persons
creditors.

Plan Amendment

4.8        Subject to
applicable law, this Plan may be amended in whole or in part at any time by the
Board without the consent of the Eligible Persons provided that such amendment
shall not materially adversely impair the rights of any Eligible Person with
respect to Deferred Share Units to which the Eligible Person is then entitled
under this Plan, except as permitted by the provisions of Section 2.7.

4.9        Shareholder
approval will be required for any amendments required to be approved by
shareholders under applicable law (including the rules, regulations and policies
of the applicable stock exchange(s) on which the Shares trade).

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4.10      Notwithstanding anything to
the contrary herein, no amendments shall be made if such amendments would cause
the Plan to breach the requirements for Regulation 6801(d), as may apply to
Eligible Persons who are taxable under the Tax Act, or the requirements of
Section 409A, as may apply to Eligible Persons under the Plan who are US
Taxpayers.

Plan Termination

4.11      The Board may terminate this
Plan at any time, but no termination will, without the consent of the Eligible
Person or unless required by law, adversely affect the rights of an Eligible
Person with respect to Deferred Share Units to which the Eligible Person is then
entitled under this Plan. In no event will a termination of this Plan accelerate
the time at which the Eligible Person would otherwise be entitled to receive a
cash payment in respect of Deferred Share Units hereunder.

Governing Law

4.12      This Plan and all matters to
which reference is made in this Plan will be governed by and construed in
accordance with the laws of Ontario and the laws of Canada applicable therein.
The Eligible Persons and the Company hereby attorn to the jurisdiction of the
courts of the Province of Ontario with respect to any and all actions in
relation thereto.

Reorganization of the Company

4.13      The existence of this Plan
or Deferred Share Units will not affect in any way the right or power of the
Company or its shareholders to make or authorize any adjustment,
recapitalization, reorganization or other change in the Companys capital
structure or its business, or to create or issue any bonds, debentures, shares
or other securities of the Company or to amend or modify the rights and
conditions attaching thereto or to effect the dissolution or liquidation of the
Company, or any amalgamation, combination, merger or consolidation involving the
Company or any sale or transfer of all or any part of its assets or business, or
any other corporate act or proceeding, whether of a similar nature or otherwise.

No Shareholder Rights

4.14      Deferred Share Units are not
considered to be Shares or securities of the Company, and an Eligible Person
whose account is credited with Deferred Share Units will not, as such, be
entitled to exercise voting rights or any other rights attaching to the
ownership of Shares of other securities of the Company, or be considered the
owner of Shares by virtue of such crediting of Deferred Share Units.

No Other Benefit

4.15      The Company makes no
representation or warranty as to the future market value of any Shares to which
the Deferred Share Units relate. No amount will be paid to, or in respect of, an
Eligible Person under this Plan to compensate for a downward fluctuation in the
price of a Share, nor will any other form of benefit be conferred upon, or in
respect of, an Eligible Person for such purpose.

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Unfunded Plan

4.16      For greater certainty, this
Plan will be an unfunded plan, including for tax purposes. Any Eligible Person
holding Deferred Share Units or related accruals under this Plan will have the
status of a general unsecured creditor of the Company with respect to any
relevant rights hereunder.

Existing Deferred Share Unit Plan

4.17       For greater certainty,
the Companys existing Deferred Share Unit Plan adopted effective May 27, 2014
(the Existing Plan) shall continue in full force and effect until such
Existing Plan is amended or terminated in accordance with its terms.

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