Exhibit 2.2



SHARE PURCHASE AGREEMENT AMENDING AGREEMENT



THIS AGREEMENT dated as of the 28th
day of January, 2015.



AMONG:

CYNAPSUS THERAPEUTICS
INC.

(hereinafter called
the “Purchaser”)



OF THE FIRST PART

- and -



THE PERSONS SET
OUT IN EXHIBIT “A” HERETO

(hereinafter collectively
called the “Shareholders”)



OF THE SECOND PART

- and -



ADAGIO PHARMACEUTICALS
LTD.

(hereinafter called
the “Corporation”)



OF THE THIRD PART



WHEREAS the Purchaser, the Shareholders
and the Corporation entered into a share purchase agreement dated as of December 22, 2011 (the “Share Purchase Agreement”),
whereby the Shareholders agreed to sell to the Purchaser, and the Purchaser agreed to purchase from the Shareholders, all of the
issued and outstanding shares in the capital of the Corporation;



AND WHEREAS the Purchaser, the Shareholders
and the Corporation wish to amend certain provisions of the Share Purchase Agreement to better reflect the contemplated agreement
between the parties, as more fully set forth in this share purchase agreement amending agreement (this “Agreement”).



NOW THEREFORE THIS AGREEMENT WITNESSETH
THAT in consideration of the mutual promises and covenants contained herein, and other good and valuable consideration, the
receipt and sufficiency of which are hereby acknowledged, the parties hereby covenant and agree as follows:



Article
1 - AMENDMENTS TO THE SHARE PURCHASE AGREEMENT



| | 1.1 | Amendment to the Definition of “Final Safety Study” in the Share Purchase Agreement
| | --- | -----------------------------------------------------------------------------------



The definition of “Final Safety Study”
on page 3 of the Share Purchase Agreement is hereby deleted in its entirety and replaced with the following:



“‘Final Safety
Study’ shall mean the final registration safety study to be conducted by the Purchaser in respect of APL-130277 which
for clarity shall consist of a study of approximately 200 to 250 Parkinson’s patients, the purpose of which is to determine
the safety of APL-130277, as based on the safety primary endpoint, as detailed in the protocol of the Final Safety Study.”











| | 1.2 | Amendment to Section 3.1(b) of the Share Purchase Agreement
| | --- | -----------------------------------------------------------



Section 3.1(b) of the Share Purchase Agreement
is hereby deleted in its entirety and replaced with the following:



“(b)          $1,500,000 of the Purchase Price shall be allocated and paid to the Shareholders as set forth in Schedule 3.1 upon successful
completion of the Phase 2 study in Parkinson’s patients (CTH-105), and receipt from the FDA of written confirmation, in a
form acceptable to the board of directors of the Purchaser, that one Phase 3 efficacy study of 150 patients or less over a 16 week
period or less, one Phase 3 safety study of 250 patients or less over a 52 week period or less, a bridging study and an ease-of-use
study, will be sufficient to allow the Purchaser to pursue approval for a new drug application (“NDA”) in respect of
APL-130277 pursuant to Subsection 505(b)(2) of the United States Federal Food, Drug and Cosmetic Act (the “505(b)(2) FDA
Confirmation”). Notwithstanding the foregoing, should the FDA advise the Purchaser that the FDA shall require one or more
additional studies or other submissions in lieu, the board of directors of the Purchaser may, in its sole discretion, pay to the
Shareholders as set forth in Schedule 3.1, all, a portion or no portion of the payment contemplated by this Section 3.1(b). Any
payment pursuant to this Section 3.1(b) shall be made by the issuance of newly issued Cynapsus Shares at a price per share equal
to the weighted average trading price of Cynapsus Shares, over a 30 day trading period, immediately preceding the first announcement
of the receipt of the 505(b)(2) FDA Confirmation, but in any event no less than the Discounted Market Price as at the close of
business on the first business day following such announcement;”.



| | 1.3 | Effective Date
| | --- | --------------



The amendments to the Share Purchase Agreement
set forth herein shall be effective as and from the date first set out above.



| | 1.4 | No Other Amendments
| | --- | -------------------



Except as expressly amended by this Agreement,
the Purchaser, the Shareholders and the Corporation hereby confirm and agree that the Share Purchase Agreement remains in full
force and effect, unamended, in accordance with the terms thereof.



| | 1.5 | References to Share Purchase Agreement
| | --- | --------------------------------------



From and after the date hereof, unless
the context otherwise requires, the Share Purchase Agreement and this Agreement shall be read together and shall have effect as
if the provisions of the Share Purchase Agreement and this Agreement were contained in one agreement. From and after the date hereof,
any reference to “this Agreement” in the Share Purchase Agreement and any reference to “the Share Purchase Agreement”
in any other agreement, document or instrument shall be and be deemed to be a reference to the Share Purchase Agreement as amended
by this Agreement.



Article
2 - GENERAL PROVISIONS



| | 2.1 | Definitions
| | --- | -----------



Unless otherwise defined herein, all capitalized
terms used in this Agreement shall have the respective meanings ascribed thereto in the Share Purchase Agreement.



- 2 -







| | 2.2 | Counterparts
| | --- | ------------



This Agreement may be executed in two or
more counterparts, each of which shall be deemed an original, but all of which together shall constitute one and the same instrument.



| | 2.3 | Governing Law; Jurisdiction
| | --- | ---------------------------



This Agreement shall be governed, construed
and, subject to Section 12.14 of the Share Purchase Agreement, enforced in accordance with the internal laws of the Province of
Ontario and the parties hereto attorn to the jurisdiction of the courts thereof, excluding any choice of law rules which may direct
the application of the laws of another jurisdiction.



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blank]



- 3 -







IN WITNESS WHEREOF, this Agreement
has been duly executed by the parties hereto on the day and year first above written.



|SIGNED, SEALED & DELIVERED |  | ) |                                                                                                                                                                 
|-------------------------- |  | - | ----------------------------------------------------------------------------------------------------------------------------------------------------------------
|in the presence of:        |  | ) |                                                                                                                                                                 
|                           |  | ) |                                                                                                                                                                 
|                           |  | ) |                                                                                                                                                                 
|/s/ Ted Heimler            |  | ) | /s/ Anthony Giovinazzo                                                                                                                                          
|Witness                    |  | ) | ANTHONY GIOVINAZZO                                                                                                                                              
|                           |  | ) |                                                                                                                                                                 
|/s/ Ted Heimler            |  | ) | /s/ Anthony Giovinazzo                                                                                                                                          
|Witness                    |  | ) | ANTHONY GIOVINAZZO on behalf of Collabrity, Inc., David Hedden, Robin Walker, Judi Weissinger, John Nardini and Joseph Giovinazzo pursuant to powers of attorney



|CYNAPSUS THERAPEUTICS INC. |                           
|-------------------------- | --------------------------
|                           |                           
|Per:                       | /s/ Andrew Williams       
|                           | Authorized Signing Officer



- 4 -







EXHIBIT “A”



| | 1. | Anthony Giovinazzo
| | -- | ------------------



| | 2. | David Hedden
| | -- | ------------



| | 3. | Robin Walker
| | -- | ------------



| | 4. | Judi Weissinger
| | -- | ---------------



| | 5. | John Nardini
| | -- | ------------



| | 6. | Joseph Giovinazzo
| | -- | -----------------



| | 7. | Collabrity, Inc.
| | -- | ----------------