Exhibit 4.1

Instruments Defining the Rights of Security Holders – Articles of Incorporation

ACASTI PHARMA INC.

Is a corporation existing under the Business Corporations Act (Québec) (R.S.Q. S-31.1) and was constituted on February 1, 2002, pursuant to Part IA of the Companies Act (Québec) (L.R.Q., ch. C-38)

SCHEDULE 1

The authorized share capital of the Company is composed of an unlimited number of Class “A”, “B”, “C”, “D” and “E” shares, with the following privileges and restrictions:

Holders of Class “A” shares:

Shall have the right to vote at any meeting of the shareholders of the Company. Each Class “A” share confers one (1) vote per share.

Shall have the right to receive, during each financial year and out of the funds which can legally serve this purpose, a dividend, of which the amount, declaration and payment thereof is left to the discretion of the Directors, subject to the order of priority defined in section 5.6.

In the event of the dissolution or the liquidation of the Company or any other distribution of its property, shall have the right to share in the remaining property of the Company, subject to the order of priority defined in section 5.6.

Shall participate in the profits or surplus assets of the Company.

Holders of Class “B” shares:

Shall have the right to vote at any meeting of the shareholders of the Company. Each Class “B” share confers ten (10) votes per share.

Shall have the right to receive, as and when such dividends are declared, an annual non-cumulative dividend of five percent (5%) on the amount paid for the said shares, payable at the time and in the manner which the Directors may determine and subject to the order of priority as defined in section 5.6.

Shall have the right, starting January 1st, 2009, at their entire discretion, to convert, part or all of the Class “B” shares they hold in Class “A” shares on the basis of one Class “A” share for each Class “B” share converted pursuant hereto.

To exercise its conversion right, a shareholder must remit to the Company’s head office a written notice indicating the number of shares which must be converted by the Company as well as the date of the conversion. This notice must be accompanied by the share certificate(s) representing the shares which will be converted and must bear the signature of the person registered on the Company’s registers as the holder of these shares or the signature of a duly authorized proxy. Upon receipt of the notice and the share certificate(s) representing the shares to be converted, the Company will dispose of fifteen (15) days to remit the new Class “A” share certificates to the shareholder. A shareholder may not claim a right as a shareholder of the converted class of shares as of the date upon which the Company shall have issued the new share certificates following the exercise of the conversion.

If part of the shares held by a shareholder are converted pursuant hereto, the Company shall, free of charge, issue to the concerned shareholder a new share certificate representing the non-converted shares.

The shares converted pursuant hereto at the request of a shareholder will be automatically cancelled at the date of issuance of the new Class “A” shares issued following the conversion and the Company shall, as required, reduce or increase accordingly the subdivision of the issued and paid share capital relating to said shares, the whole in accordance with the provisions of the law.

Subject to the provisions of the Companies Act (Quebec) and the order of priority defined in section 5.6, have the right to demand from the Company, upon a thirty (30) day written notice, that the latter redeem the Class “B” shares that are held by the shareholder(s) at a price equivalent to the amount paid for said shares plus the redemption premium as defined in subsection 5.2.4.1, and any and all declared but yet unpaid dividends on same. In the event of partial redemption, such redemption shall be made in proportion with the number of outstanding Class “B” shares, without taking into account share fractions.

Subject to the provisions of the Companies Act (Quebec), the Company may, when it so deems advisable, without notice and without taking into account any other classes of shares, purchase by mutual agreement, at the best possible price, all or part of the outstanding Class “B” shares, which price shall not exceed, in any way, the aforementioned redemption price.

In the event of the dissolution or liquidation of the Company or any other distribution of its property, shall have the right to be reimbursed for the amount paid on Class “B” shares plus the redemption premium as defined in subsection 5.2.4.1 as well as the amount of any and all declared but yet unpaid dividends on said shares, subject to the order of priority defined in section 5.6.

Subject to the provisions of subsection 5.2.2, shall not have the right to participate in the profits or surplus assets of the Company.

Holders of Class “C” shares:

Subject to the provisions of the Companies Act (Quebec), shall neither be entitled to vote at any meeting of the shareholders of the Company, nor to receive a notice of such meeting nor to attend any such meeting.

Shall have the right to receive, as and when such dividends are declared, an annual non-cumulative dividend of five percent (5%) on the amount paid for the said shares, plus a redemption premium as defined in subsection 5.3.6.1, payable at the time and in the manner which the Directors may determine and subject to the order of priority as defined in section 5.6.

Subject to the provisions of subsection 5.3.2, shall not have the right to participate in the profits or surplus assets of the Company.

Shall have the right, starting January 1 ^st , 2009, at their entire discretion, to convert, part or all of the Class “C” shares they hold in Class “A” shares on the basis of one Class “A” share for each Class “C” share converted pursuant hereto.

To exercise its conversion right, a shareholder must remit to the Company’s head office a written notice indicating the number of shares which must be converted by the Company as well as the date of the conversion. This notice must be accompanied by the share certificate(s) representing the shares which will be converted and must bear the signature of the person registered on the Company’s registers as the holder of these shares or the signature of a duly authorized proxy. Upon receipt of

the notice and the share certificate(s) representing the shares to be converted, the Company will dispose of fifteen (15) days to remit the new Class “A” share certificates to the shareholder. A shareholder may not claim a right as a shareholder of the converted class of shares as of the date upon which the Company shall have issued the new share certificates following the exercise of the conversion.

If part of the shares held by a shareholder are converted pursuant hereto, the Company shall, free of charge, issue to the concerned shareholder a new share certificate representing the non-converted shares.

The shares converted pursuant hereto at the request of a shareholder will be automatically cancelled at the date of issuance of the new Class “A” shares issued following the conversion and the Company shall, as required, reduce or increase accordingly the subdivision of the issued and paid share capital relating to said shares, the whole in accordance with the provisions of the law.

All of the Company’s Class “C” shares shall automatically be converted in Class “A” shares upon the request of an unrelated third party investor in the Company, investing more than $500,000, or any other amount to be determined by the Board of Directors of the Company, in the Company and requesting as a condition to the investment that the Class “C” shares be converted into Class “A” shares on the basis of one Class “A” share for each Class “C” share converted pursuant hereto.

In such case, the Company shall send a notice to the holders of Class “C” shares requesting the share certificate(s) representing the shares which will be converted. Upon receipt of the share certificate(s) representing the shares to be converted, the Company will dispose of fifteen (15) days to remit the new Class “A” share certificates to the shareholders. A shareholder may not claim a right as a shareholder of the converted class of shares as of the date upon which the Company shall have issued the new share certificates following the exercise of the conversion.

The shares converted pursuant hereto will be automatically cancelled at the date of issuance of the new Class “A” shares issued following the conversion and the Company shall, as required, reduce or increase accordingly the subdivision of the issued and paid share capital relating to said shares, the whole in accordance with the provisions of the law.

Subject to the provisions of the Companies Act (Quebec) and the order of priority defined in section 5.6, have the right to demand from the Company, upon a thirty (30) day written notice, that the latter redeem the Class “C” shares that are held by the shareholder(s) at a price equivalent to

the amount paid for said shares plus the redemption premium as defined in subsection 5.3.6.1, and any and all declared but yet unpaid dividends on same. In the event of partial redemption, such redemption shall be made in proportion with the number of outstanding Class “C” shares, without taking into account share fractions.

Subject to the provisions of the Companies Act (Quebec), the Company may, when it so deems advisable, without notice and without taking into account any other classes of shares, purchase by mutual agreement, at the best possible price, all or part of the outstanding Class “C” shares, which price shall not exceed, in any way, the aforementioned redemption price.

In the event of the dissolution or liquidation of the Company or any other distribution of its property, shall have the right to be reimbursed for the amount paid on Class “C” shares plus the redemption premium as defined in subsection 5.3.6.1 as well as the amount of any and all declared but yet unpaid dividends on said shares, subject to the order of priority defined in section 5.6.

Holders of Class “D” shares:

Subject to the provisions of the Companies Act (Quebec), shall neither be entitled to vote at any meeting of the shareholders of the Company, nor to receive a notice of such meeting nor to attend any such meeting.

Shall have the right to receive, as and when such dividends are declared, a monthly variable non-cumulative dividend of half of one percent to two percent (0.5% to 2%) on the amount paid for the said shares, plus a redemption premium as defined in subsection 5.4.6.1, payable at the time and in the manner which the Directors may determine and subject to the order of priority as defined in section 5.6.

Subject to the provisions of subsection 5.4.2, shall not have the right to participate in the profits or surplus assets of the Company.

Shall have the right, starting January 1 ^st , 2009, at their entire discretion, to convert, part or all of the Class “D” shares they hold in Class “A” shares on the basis of a number of Class “A” shares equal to the number of Class “D” shares converted pursuant hereto multiplied by the conversion ratio, calculated as follows:

Fair Market Value of the Class “A” shares at the date of any conversion of

Class “D” shares in Class “A” shares

To exercise its conversion right, a shareholder must remit to the Company’s head office a written notice indicating the number of shares which must be converted by the Company as well as the date of the conversion. This notice must be accompanied by the share certificate(s) representing the shares which will be converted and must bear the signature of the person registered on the Company’s registers as the holder of these shares or the signature of a duly authorized proxy. Upon receipt of the notice and the share certificate(s) representing the shares to be converted, the Company will dispose of fifteen (15) days to remit the new Class “A” share certificates to the shareholder. A shareholder may not claim a right as a shareholder of the converted class of shares as of the date upon which the Company shall have issued the new share certificates following the exercise of the conversion.

If part of the shares held by a shareholder are converted pursuant hereto, the Company shall, free of charge, issue to the concerned shareholder a new share certificate representing the non-converted shares.

The shares converted pursuant hereto at the request of a shareholder will be automatically cancelled at the date of issuance of the new Class “A” shares issued following the conversion and the Company shall, as required, reduce or increase accordingly the subdivision of the issued and paid share capital relating to said shares, the whole in accordance with the provisions of the law.

All of the Company’s Class “D” shares shall automatically be converted in Class “A” shares upon the request of an unrelated third party investor in the Company, investing more than $500,000, or any other amount to be determined by the Board of Directors of the Company, in the Company and requesting as a condition to the investment that the Class “D” shares be converted into Class “A” shares on the basis of a number of Class “A” shares equal to the number of Class “D” shares converted pursuant hereto multiplied by the conversion ratio, calculated as follows:

Fair Market Value of the Class “A” shares at the date of any conversion of

Class “D” shares in Class “A” shares

In such case, the Company shall send a notice to the holders of Class “D” shares requesting the share certificate(s) representing the shares which will be converted. Upon receipt of the share certificate(s) representing the shares to be converted, the Company will dispose of fifteen (15) days to remit the new Class “A” share certificates to the shareholders. A shareholder may not claim a right as a shareholder of the converted class of shares as of the date upon which the Company shall have issued the new share certificates following the exercise of the conversion.

The shares converted pursuant hereto will be automatically cancelled at the date of issuance of the new Class “A” shares issued following the conversion and the Company shall, as required, reduce or increase accordingly the subdivision of the issued and paid share capital relating to said shares, the whole in accordance with the provisions of the law.

Subject to the provisions of the Companies Act (Quebec) and the order of priority defined in section 5.6, have the right to demand from the Company, upon a thirty (30) day written notice, that the latter redeem the Class “D” shares that are held by the shareholder(s) at a price equivalent to the amount paid for said shares plus the redemption premium as defined in subsection 5.4.6.1, and any and all declared but yet unpaid dividends on same. In the event of partial redemption, such redemption shall be made in proportion with the number of outstanding Class “D” shares, without taking into account share fractions.

Subject to the provisions of the Companies Act (Quebec), the Company may, when it so deems advisable, without notice and without taking into account any other classes of shares, purchase by mutual agreement, at the best possible price, all or part of the outstanding Class “D” shares, which price shall not exceed, in any way, the aforementioned redemption price.

In the event of the dissolution or liquidation of the Company or any other distribution of its property, shall have the right to be reimbursed for the amount paid on Class “D” shares plus the redemption premium as defined in subsection 5.4.6.1 as well as the amount of any and all declared but yet unpaid dividends on said shares, subject to the order of priority defined in section 5.6.

Holders of Class “E” shares:

Subject to the provisions of the Companies Act (Quebec), shall neither be entitled to vote at any meeting of the shareholders of the Company, nor to receive a notice of such meeting nor to attend any such meeting.

Shall have the right to receive, as and when such dividends are declared, a monthly variable non-cumulative dividend of half of one percent to two percent (0.5% to 2%) on the amount paid for said shares, payable at a time and in the manner in which the Directors may determine and subject to the order of priority as defined in section 5.6.

Subject to the provisions of subsection 5.5.2, shall not participate in the profits or surplus assets of the Company.

Subject to the provisions of the Companies Act (Quebec) and the order of priority defined in section 5.6 hereof, the Company shall have the right to redeem, upon a thirty (30) day written notice, the Class “E” shares that are held by the shareholder(s) at a price equivalent to the amount paid on said shares and any and all declared but yet unpaid dividends on same. In the event of partial redemption, such redemption shall be made in proportion with the number of outstanding Class “E” shares, without taking into account share fractions.

Shall have the right, at their entire discretion, to convert, part or all of the Class “E” shares they hold in Class “A” shares on the basis of a number of Class “A” shares equal to the number of Class “E” shares converted pursuant hereto multiplied by the conversion ratio, calculated as follows:

Fair Market Value of the Class “A” shares at the date of any conversion of

Class “E” shares in Class “A” shares

To exercise its conversion right, a shareholder must remit to the Company’s head office a written notice indicating the number of shares which must be converted by the Company as well as the date of the conversion. This notice must be accompanied by the share certificate(s) representing the shares which will be converted and must bear the signature of the person registered on the Company’s registers as the holder of these shares or the signature of a duly authorized proxy. Upon receipt of the notice and the share certificate(s) representing the shares to be converted, the Company will dispose of fifteen (15) days to remit the new Class “A” share certificates to the shareholder. A shareholder may not claim a right as a shareholder of the converted class of shares as of the date upon which the Company shall have issued the new share certificates following the exercise of the conversion.

If part of the shares held by a shareholder are converted pursuant hereto, the Company shall, free of charge, issue to the concerned shareholder a new share certificate representing the non-converted shares.

The shares converted pursuant hereto at the request of a shareholder will be automatically cancelled at the date of issuance of the new Class “A” shares issued following the conversion and the Company shall, as required, reduce or increase accordingly the subdivision of the issued and paid share capital relating to said shares, the whole in accordance with the provisions of the law.

Subject to the provisions of the Companies Act (Quebec), the Company may, when it so deems advisable, without notice and without taking into account any other classes of shares, purchase by mutual agreement, at the best possible price, all or part of the outstanding Class “E” shares.

In the event of the dissolution or the liquidation of the Company or any other distribution of its property, shall have the right to be reimbursed for the amount paid on Class “E” shares as well as the amount of any and all declared yet unpaid dividends on said shares, subject to the order of priority defined in section 5.6.

The order of priority applicable to all classes of shares of the Company with respect to the redemption, liquidation, dissolution or distribution of property is as follows:

Notwithstanding the above-mentioned order of priority, shareholders of a class of shares may renounce to the above-mentioned order of priority by unanimous approval by all shareholders of said class of shares.

The issued and outstanding Class “A” shares of the share capital of the Company prior to the amendment are converted as follows:

The One Hundred (100) Class A shares of the issued and outstanding share capital of the Company, prior to this amendment, are converted into One Hundred (100) Class A shares, for a total stated capital of One Hundred Dollars ($ 100).

SCHEDULE 2

The Board of Directors may, by resolution and without the approval of the shareholders:

Exhibit 4.2

TABLE OF CONTENT

ACASTI PHARMA INC. – BY-LAW NO. 1

GENERAL BY-LAW RELATING TO THE BUSINESS OF THE COMPANY

BY-LAW NO. 1

GENERAL BY-LAW RELATING TO THE BUSINESS OF THE COMPANY

Unless otherwise provided in the present by-law, the following must be interpreted in accordance with the Quebec Companies Act (R.S.Q., c. c-38) including any subsequent amendment thereto and any law that may be substituted therefore, hereinafter the “Act”.

In the present by-law, the term “Articles” refers to the articles of incorporation of the Company and to all subsequent amendments thereto filed with the Inspector general of financial institutions.

The words and expressions defined in the Act have the same meaning for the purposes of this by-law.

Words importing the singular number include plural and vice-versa, and words importing gender is deemed to include the masculine and the feminine.

Words referring to persons are deemed to include individuals, incorporated or non-incorporated companies, companies, corporations, trusts as wells as non-incorporated organizations.

Each time a provision of this by-law or of any other by-law of the Company is in conflict with or contradicts the provisions of a “Unanimous Shareholders Agreement” as described in article 123.91 of the Act, the provisions of the “Unanimous Shareholders Agreement” shall prevail.

The Board of Directors establishes, by means of a resolution:

Any director or other person designated by the Board of Directors shall be authorized and empowered to:

At the end of each fiscal year, within the delays prescribed by the Act, an annual general meeting of the shareholders of the Company shall be held on such date and at such time as may be fixed by the Board of Directors, to receive and consider the financial statements, to elect directors, and, as the case may be, the report of the auditor as well as to the appointment or renewal of the mandate of the latter.

The annual meeting of the shareholders shall be held at the head office of the Company or at any other place which may be determined by the Board of Directors.

Notice of the date, time and place of the meeting and the nature of any special business to be considered at such meeting shall be delivered to each shareholders entitled to vote at the meeting, to each director and to the auditor of the Company. Said notice shall be sent not less than ten (10) days prior to the date fixed for the meeting.

A shareholder and any other person permitted to assist at such meeting, may waive the notice thereof or consent to its being held; the attendance by any person at such meeting shall be deemed a waiver on his part to notice thereof, unless such person attends the meeting for the purpose of objecting to the proceedings on the grounds that the meeting was not validly called.

A meeting of the shareholders may be held validly at any time and any place permitted by the Act without the notice:

All business of the Company that may be transacted at a shareholders meeting may be transacted at such a meeting. If the meeting is held outside of the province of Quebec, the shareholders who are not present or who are not represented by proxy and who have waived notice of the meeting or have consented to the holding thereof, are deemed to have consented to the holding of the meeting in such place.

During any meeting of the shareholders, the attendance, in person or by proxy, of the shareholders representing not less than ten percent (10%) of the shares of the share capital of the Company shall constitute a quorum.

Subject to the Articles of the Company, each shareholder entitled to vote at a meeting of the shareholders and who is in attendance, in person or by proxy, has the right to one vote per voting share that is registered in his name in the securities’ register of the Company.

Any shareholder entitled to vote at a meeting of the shareholders may appoint a proxyholder, who need not be a shareholder, to attend the meeting and to act thereat within the limits set out in the proxy. The instrument in writing appointing a proxyholder shall be signed by the shareholder or by his personal representative, so authorized in writing and shall be in conformity with the Act.

The Board of Directors, in the notice of a shareholders meeting, may specify a deadline for the filing of proxies to be used during the meeting, which, excluding any non-juridical days or holidays, may not precede by more than forty-eight (48) hours the date of the meeting.

A proxy is only valid for the purposes of the meeting if, prior to the date set out in the preceding paragraph, the proxy has been filed with the Company or its designated representative named in the notice or, if no date was specified in the notice, in the hands of the Secretary of the Company or the President of the meeting prior to the time planned for the vote.

Subject to the provisions of the Act, the Articles, of a Unanimous Shareholders Agreement or any other by-law of the Company, any matter submitted to a meeting of shareholders will be decided by a majority of the votes cast.

In the event of a tie, neither the chairman of the meeting nor any directors or officer shall have a casting vote.

During a meeting of the shareholders, the vote shall be taken by a show of hands, unless a shareholder or proxyholder having the right to vote at such meeting requests a vote by secret ballot and that this proposal is approved by the majority of votes.

Unless otherwise provided for in the Act, a resolution signed by all the shareholders entitled to vote thereon, shall have the same effect and be as valid as if it had been passed unanimously at a shareholders meeting.

If the Company has a single shareholder or a sole holder of shares of a class or series, the shareholder, whether in person or by proxy, constitutes a meeting.

Pursuant to article 123.73 of the Act, the Board of Directors is composed of directors who, must possess the qualities required by them by meeting of the shareholders, as the case may be.

The number of directors shall be determined annually by the shareholders, within the limits imposed by the Articles of the Company.

A majority of the directors in office or the minimal number of directors prescribed for in the Articles, shall constitute a quorum for a meeting of the Board of Directors, subject to a resolution to the contrary adopted by the shareholders of the Company.

The directors shall be elected by the shareholders at the first meeting of the shareholders and thereafter at each annual meeting of the shareholders. All directors then in office must then resign but remain eligible for re-election. If the election of directors is not held within the prescribed time, the then elected directors shall remain in office until the following annual meeting or the election of their successors.

Subject to the Act, any director may be removed from office by way an ordinary resolution of the shareholders passed at a special meeting called for such purpose.

A vacancy created on the Board of Directors due to a death, a resignation or if a director is no longer qualified to fulfill his duties, excluding a vacancy resulting from the increase of the number of directors on the board, may be filled by the remaining directors provided a quorum exists, or otherwise byway of a shareholders meeting.

The directors may continue to act notwithstanding one or more vacancies, provided a quorum exists.

Subject to a Unanimous Shareholders Agreement, the directors shall supervise the business and the affairs of the Company. Subject to article 4.10 of this by-law, the hoard of directors shall exercise its powers by way of resolutions adopted at a meeting where a quorum existed or by written resolution signed by all directors having the right to vote on such resolutions at a meeting of the board of directors.

Meetings of the Board of Directors may be called by any director of the Company.

A Notice of a meeting setting out the date, time and place of thereof as well as its object and the business to be considered thereat shall be sent to each director, by mail, delivered in person or by telegraph, at least ten (10) days prior to the date fixed for the meeting.

A director may at any time and in any manner waive his right to receive notice of a meeting of the Board of Directors or otherwise consent to such a meeting. The attendance of a director at the meeting, in itself, shall constitute a waiver, except where he indicates that he is attending the meeting for the express purpose of objecting to the proceedings on the grounds that the meeting has not been validly called.

A Director may, if all directors are in agreement. participate in a board meeting using means permitting all participants to communicate orally amongst themselves A director participating in the meeting by such means shall be deemed to have attended the meeting.

A written resolution, signed by all the directors entitled to vote on that resolution at a meeting of the directors, shall be valid and shall have the same effect as if it had been adopted at a meeting of the Board of Directors duly called and held.

Each director shall be entitled to one vote. All matters shall be decided by a majority of the votes cast and, in the event of a tie, the president shall not have a second or casting vote.

If the Company has a sole director, said director constitutes the Board of Directors.

Subject to a Unanimous Shareholders Agreement, the remuneration to be paid to the directors for their services shall be such as the Board of Directors shall determine from time to time. Directors shall be reimbursed for reasonable and necessary expenses incurred by them in the exercise of their duties. No provision hereof shall prevent a director from occupying an office or position with the Company and from receiving remuneration as a result thereof.

Subject to the provisions of the Articles, or of any Unanimous Shareholders Agreement, the Board of Directors may annually or as necessary, appoint a person to the office of President, one or more Vice-Presidents, a Secretary, one or more assistant Secretaries, a Treasurer and one or more assistant Treasurers. None of these officers need necessarily be a director of the Company. Where the same person holds the offices of Secretary and Treasurer, that person may be designated as the Secretary-Treasurer.

Subject to the Act, to the Articles, to the By-laws and to any resolution of the Board of Directors on the subject, the officers have the powers and assume all responsibility which normally relate to their office.

The Board of Directors may create such other offices as it may deem necessary and name such officers, employees or mandataries to serve as such, as may be deemed appropriate thereon. The powers of these offices shall be limited to those powers granted to them by resolution.

The same person may hold two or more offices within the Company.

The term of office of the officers and of the representatives of the Corporation shall begin with their acceptance of the office and shall continue until their successors or their replacements have been appointed.

Any officer may resign his office at any time by delivering his resignation in writing to the Board of Directors of the Company. Any Officer may be removed from office at any time with or without reason, by resolution adopted by a majority of the directors, subject at all times, to the provisions of a contract which may bind him to the company.

In the case of an officer’s absence, incapacity or a refusal to act, or far any other reason which the Board deems sufficient, the latter may delegate, for whatever time necessary, all or a portion of the powers of such officer to another officer or director.

Any vacancy occurring in the office of any officer may be filled by the Board of Directors.

Subject to a Unanimous Shareholders Agreement, the officers and other employees of the Company will be remunerated for their services, such remuneration to be determined from time to time by the Board of Directors.

Subject to the limits permitted by the Act, the Company shall indemnify a director or officer, a former director or officer of the Company or any other person acting or having acted, upon request of the Company, as director or officer of the legal person of which the Company is or was a shareholder or creditor, as well as legal heirs and representatives

of such person, against all costs, charges and expenses, including an amount paid to settle an action or satisfy e judgement, reasonably incurred in an action or any civil, criminal or administrative proceeding in which the individual was a party due to the fact that he is or was a director or officer of the Company, if such person acted with integrity and good faith in the best interests of the Company and, in the case of a criminal or administrative action or proceeding that is enforced by a monetary penalty, the individual had reasonable grounds for believing that his conduct was in conformity with the Act.

Without limiting the generality of article 6.1, the directors of the Company are hereby authorized, without further approval or confirmation from the shareholders, to cause the Company to indemnify any director or other person whose liability is or will be engaged for the benefit of the Company and to guarantee by hypothec or otherwise, the reimbursement of any loss that this director may suffer from such liability.

Subject to the Articles of the Company, the By-Laws or a Unanimous Shareholders Agreement, the shares of the share capital of the Company or options for the purchase of same, may be issued at such periods, to such persons and for such consideration as may be determined by resolution of the Board of Directors.

The share certificates, the form of which is approved by resolution of the Board of Directors, must be signed by at least one director or officer of the Company, or as may be otherwise determined by the Board of Directors.

The Board of Directors may, from time to time, adopt or enact new By-Laws, which must not be contrary to the Act or the Articles of the Company. The Board may adopt, abrogate, amend or re-enact other By-Laws of the Company.

Exhibit 4.3

ADVANCE NOTICE BY-LAW

BY-LAW NO. 2013-1

A BY-LAW RELATING GENERALLY TO THE ADVANCE

NOTICE REQUIREMENTS FOR THE NOMINATION OF

DIRECTORS OF ACASTI PHARMA INC.

(the “Corporation”)

INTRODUCTION

The purpose of this advance notice by-law (the “Advance Notice By-Law”) is to establish the conditions and framework under which holders of record of common shares of the Corporation may exercise their right to submit director nominations by fixing a deadline by which such nominations must be submitted by a shareholder to the Corporation prior to any annual or special meeting of shareholders, and sets forth the information that a shareholder must include in the notice to the Corporation for the notice to be in proper form.

It is the position of the Corporation that this Advance Notice By-Law is beneficial to shareholders and other stakeholders of the Corporation.

NOMINATIONS OF DIRECTORS

a. by or at the direction of the Board, including pursuant to a notice of meeting;

b. by or at the direction or request of one or more shareholders of the Corporation pursuant to a proposal made in accordance with the provisions of the Act, or a requisition of meeting of the shareholders of the Corporation made in accordance with the provisions of the Act; or

c. by any person (a “Nominating Shareholder”): (A) who, at the close of business on the date of the giving of the notice provided below in this Advance Notice By-Law and on the record date for notice of such meeting, is entered in the securities register of the Corporation as a holder of one or more shares carrying the right to vote at such meeting or who beneficially owns shares that are entitled to be voted at such meeting; and (B) who complies with the notice procedures set forth below in this Advance Notice By-Law.

a. in the case of an annual meeting of shareholders, not less than 30 nor more than 65 days prior to the date of the annual meeting of shareholders; provided, however, that in the event that the annual meeting of shareholders is to be held on a date that is less than 50 days after the date on which the first public announcement (the “Notice Date”) of the date of the annual meeting was made, notice by the Nominating Shareholder may be made not later than the close of business on the 10th day following the Notice Date; and

b. in the case of a special meeting (which is not also an annual meeting) of shareholders called for the purpose of electing directors (whether or not called for other purposes), not later than the close of business on the 15th day following the day on which the first public announcement of the date of the special meeting of shareholders was made.

c. In no event shall any adjournment or postponement of a meeting of shareholders or the announcement thereof commence a new time period for the giving of a Nominating Shareholder’s notice as described above.

a. as to each person whom the Nominating Shareholder proposes to nominate for election as a director: (A) the name, age, business address and residential address of the person; (B) the principal occupation or employment of the person; (C) the class or series and number of shares in

the capital of the Corporation which are controlled or which are owned beneficially or of record by the person as of the record date for the meeting of shareholders (if such date shall then have been made publicly available and shall have occurred) and as of the date of such notice; and (D) any other information relating to the person that would be required to be disclosed in a dissident’s proxy circular in connection with solicitations of proxies for election of directors pursuant to the Act and Applicable Securities Laws (as defined below); and

b. as to the Nominating Shareholder giving the notice, any proxy, contract, arrangement, understanding or relationship pursuant to which such Nominating Shareholder has a right to vote any shares of the Corporation and any other information relating to such Nominating Shareholder that would be required to be made in a dissident’s proxy circular in connection with solicitations of proxies for election of directors pursuant to the Act and Applicable Securities Laws (as defined below).

The Corporation may require any proposed director nominee to furnish such other information as may reasonably be required by the Corporation to determine the eligibility of such proposed director nominee to serve as an independent director of the Corporation or that could be material to a reasonable shareholder of the Corporation’s understanding of the independence, or lack thereof, of such proposed director nominee.

a. “public announcement” shall mean disclosure in a press release reported by a national news service in Canada, or in a document publicly filed by the Corporation under its profile on the System of Electronic Document Analysis and Retrieval at www.sedar.com; and

b. “Applicable Securities Laws” means the applicable securities legislation of each relevant province of Canada, as amended from time to time, the rules, regulations and forms made or promulgated under any such statute and the published national instruments, multilateral instruments, policies, bulletins and notices of the securities commission and similar regulatory authority of each province of Canada.

Notwithstanding the foregoing, the Board may, in its sole discretion, waive any requirement in this Advance Notice By-Law.

Adopted by the Board May 9, 2013.

********

Exhibit 4.4

ACASTI PHARMA INC.

EQUITY INCENTIVE PLAN

JUNE 27, 2013

Acasti Pharma Inc.

Equity Incentive Plan

ARTICLE 1

PURPOSE

The purpose of this Plan is to provide the Corporation with a share-related mechanism to attract, retain and motivate qualified Directors, Employees and Consultants of the Corporation and its Subsidiaries, to reward such of those Directors, Employees and Consultants as may be granted Awards under this Plan by the Board from time to time for their contributions toward the long term goals and success of the Corporation and to enable and encourage such Directors, Employees and Consultants to acquire Shares as long term investments and proprietary interests in the Corporation.

ARTICLE 2

INTERPRETATION

When used herein, unless the context otherwise requires, the following terms have the indicated meanings, respectively:

“Affiliate” has the meaning set forth in the Securities Act;

“Associate” has the meaning ascribed to it in the Securities Act;

“Award” means any Bonus Share, Restricted Share Unit, Performance Share Unit, Deferred Share Unit, Restricted Share or Other Share-Based Award granted under this Plan;

“Award Agreement” means a signed, written agreement between a Participant and the Corporation, substantially in the form attached as Schedule A, subject to any amendments or additions thereto as may, in the discretion of the Board, be necessary or advisable, evidencing the terms and conditions on which an Award has been granted under this Plan;

“Award Value” means such percentage of annual base salary or such other amount as may be determined from time to time by the Board as the original value of the Award to be paid to a Participant and specified in the Participant’s Award Agreement;

“Board” means the board of directors of the Corporation;

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“Business Day” means a day, other than a Saturday or Sunday, on which the principal commercial banks in the City of Montréal are open for commercial business during normal banking hours;

“Bonus Share” means Shares issued to a Participant under the terms of this Plan;

“Cause” means, with respect to a particular Employee:

“Change in Control” means the occurrence of any one or more of the following events:

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For the purposes of the foregoing, “ Voting Securities ” means Shares and any other shares entitled to vote for the election of directors and shall include any security, whether or not issued by the Corporation, which are not shares entitled to vote for the election of directors but are convertible into or exchangeable for shares which are entitled to vote for the election of directors including any options or rights to purchase such shares or securities.

Notwithstanding the foregoing definition, for Awards that are non-qualified deferred compensation held by a U.S. Taxpayer, any Change in Control must also meet the requirements for a “change in control” or “change in ownership” under Section 409A;

“Code” means the U.S. Internal Revenue Code of 1986, as amended from time to time, and the regulations promulgated under it;

“Committee” has the meaning set forth in Section 3.2;

“Corporation” means Acasti Pharma Inc.;

“Consultant” means an individual or Consultant Company, other than an Employee or a Director of the Corporation, that:

“Consultant Company” means for an individual consultant, a company or partnership of which the individual is an employee, shareholder or partner;

“Date of Grant” means, for any Award, the date specified by the Board at the time it grants the Award (which, for greater certainty, shall be no earlier than the date on which the Board meets for the purpose of granting such Award) or if no such date is specified, the date upon which the Award was granted;

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“Deferred Share Unit” or “DSU” means a unit equivalent in value to a Share, credited by means of a bookkeeping entry in the books of the Corporation in accordance with ARTICLE 7;

“Director” means a director of the Corporation who is not an employee of the Corporation or a Subsidiary;

“Disabled” or “Disability” means the permanent and total incapacity of a Participant as determined in accordance with procedures established by the Board for purposes of this Plan;

“Distribution” has the meaning set forth in the Securities Act;

“Effective Date” means the effective date of this Plan, being June 27, 2013;

“Employee” means an individual who:

“Exchange” means such stock exchange or other organized market on which the Shares are or may be listed or posted for trading from time to time, including as applicable the TSX-V or the TSX;

“Exchange Act” means the United States Securities Exchange Act of 1934, as amended from time to time;

“Insider” means an “insider” as defined by the Exchange from time to time in its rules and regulations;

“Investor Relations Activities” means any activities, by or on behalf of the Corporation or shareholder of the Corporation, that promote or reasonably could be expected to promote the purchase or sale of securities of the Corporation, but does not include:

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activities or communications that may be otherwise specified by the Exchange.

“Market Price” at any date in respect of the Shares shall be the closing price of such Shares on the Exchange (and if listed on more than one stock exchange, then the highest of such closing prices) on the last Business Day prior to the relevant date. In the event that such Shares did not trade on such Business Day, the Market Price shall be the average of the bid and asked prices in respect of such Shares at the close of trading on such date. In the event that such Shares are not listed and posted for trading on any stock exchange, the Market Price shall be the fair market value of such Shares as determined by the Board in its sole discretion;

“NI 45-106” means National Instrument 45-106 Prospectus and Registration Exemptions of the Canadian Securities Administrators, as amended from time to time;

“Other Share-Based Award” means any right granted under Section 8.1;

“Participant” means an Employee, Consultant or Director to whom an Award has been granted under this Plan;

“Participant’s Employer” means the Corporation or such Subsidiary as is or, if the Participant has ceased to be employed by the Corporation or such Subsidiary, was the Participant’s Employer;

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“Performance Goals” means performance goals expressed in terms of attaining a specified level of the particular criteria or the attainment of a percentage increase or decrease in the particular criteria, and may be applied to one or more of the Corporation, a Subsidiary, or a division or strategic business unit of the Corporation, or may be applied to the performance of the Corporation relative to a market index, a group of other companies or a combination thereof, all as determined by the Board;

“Performance Share Unit” or “PSU” means any right granted under Section 5.1 of the Plan;

“Permitted Assign” has the meaning assigned to that term in NI 45-106;

“Person” includes an individual, sole proprietorship, partnership, unincorporated association, unincorporated syndicate, unincorporated organization, trust, body corporate, and a natural person in his or her capacity as trustee, executor, administrator or other legal representative;

“Plan” means this Acasti Pharma Inc. Equity Incentive Plan, as may be amended from time to time;

“QBCA” means the Business Corporations Act (Québec), as amended, or such other successor legislation which may be enacted, from time to time;

“Regulatory Authorities” means the Exchange and any other organized trading facilities on which the Corporation’s Shares are listed and all securities commissions or similar securities regulatory bodies having jurisdiction over the Corporation;

“Restricted Period” means the period during which Restricted Shares are subject to restrictions as set out in the Award Agreement;

“Restricted Shares” means Shares granted to a Participant under Section 6.1 hereof that are subject to certain restrictions and to a risk of forfeiture;

“Restricted Share Unit” or “RSU” means a right to receive a Share or a Restricted Share granted, as determined by the Board, under Section 4.1;

“Securities Act” means the Securities Act (Québec), as amended, or such other successor legislation as may be enacted, from time to time;

“Securities Laws” means securities legislation, securities regulation and securities rules, as amended, and the policies, notices, instruments and blanket orders in force from time to time that govern or are applicable to the Corporation or to which it is subject, including, without limitation, the Securities Act;

“Share” means one (1) common share without par value in the capital stock of the Corporation as constituted on the Effective Date or, in the event of an adjustment contemplated by ARTICLE 12, such other shares or securities to which the holder of an Award may be entitled as a result of such adjustment;

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“Stock Option Plan” means the Corporation’s stock option plan in effect from time to time;

“Termination Date” means, in the case of a Participant whose employment or term of office or engagement with the Corporation or an Affiliate terminates:

provided that in the case of termination by reason of voluntary resignation by the Participant, such date shall not be earlier than the date that notice of resignation was received from such Participant, and “Termination Date” in any such case specifically does not mean the date on which any period of contractual notice, reasonable notice, salary continuation or deemed employment that the Corporation or the Affiliate, as the case may be, may be required at law to provide to a Participant would expire;

“TSX-V” means the TSX Venture Exchange;

“TSX ” means the Toronto Stock Exchange; and

“U.S. Taxpayer” shall mean a Participant who is a U.S. citizen, U.S. permanent resident or individual providing services to the Corporation or its Subsidiaries in the U.S.

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ARTICLE 3

ADMINISTRATION

Subject to Section 3.2, this Plan will be administered by the Board and the Board has sole and complete authority, in its discretion, to:

including any conditions relating to the attainment of specified Performance Goals;

The Board’s determinations and actions within its authority under this Plan are conclusive and binding on the Corporation and all other persons. The day-to-day administration of the Plan may be delegated to such officers and employees of the Corporation or of a Subsidiary as the Board determines.

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To the extent permitted by applicable law and the Corporation’s articles, the Board may, from time to time, delegate to a committee (the “Committee” ) of the Board, all or any of the powers conferred on the Board under the Plan. In connection with such delegation, the Committee will exercise the powers delegated to it by the Board in the manner and on the terms authorized by the Board. Any decision made or action taken by the Committee arising out of or in connection with the administration or interpretation of this Plan in this context is final and conclusive. Notwithstanding any such delegation or any reference to the Committee in this Plan, the Board may also take any action and exercise any powers that the Committee is authorized to take or has power to exercise under this Plan.

All Employees, Consultants and Directors are eligible to participate in the Plan, subject to subsections 10.11(c) and 10.2(g). Eligibility to participate does not confer upon any Employee, Consultant or Director any right to receive any grant of an Award pursuant to the Plan. The extent to which any Employee, Consultant or Director is entitled to receive a grant of an Award pursuant to the Plan will be determined in the sole and absolute discretion of the Board.

Any Award granted under this Plan shall be subject to the requirement that, if at any time the Corporation shall determine that the listing, registration or qualification of the Shares issuable pursuant to such Award upon any securities exchange or under any Securities Laws of any jurisdiction, or the consent or approval of Regulatory Authority, is necessary as a condition of, or in connection with, the grant or exercise of such Award or the issuance or purchase of Shares thereunder, such Award may not be accepted or exercised in whole or in part unless such listing, registration, qualification, consent or approval shall have been effected or obtained on conditions acceptable to the Board. Nothing herein shall be deemed to require the Corporation to apply for or to obtain such listing, registration, qualification, consent or approval.

The Board may only grant Awards to an Employee or Consultant if such Employee or Consultant is a bona fide Employee or Consultant of the Corporation or a Subsidiary of the Corporation, as the case may be. The Board may, in its sole discretion, grant the majority of the Awards to Insiders of the Corporation. The number of Shares that may be purchased under any Award or the amount of any Award that shall be granted in any form that may result in the issuance of Shares will be determined and fixed by the Board at the date of grant, provided that:

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pursuant to this Plan, or when combined with all of Corporation’s other security based share compensation arrangements shall not, in aggregate, exceed 10% of the total number of Outstanding Shares on a non-diluted basis.

Subject to adjustment as provided for in ARTICLE 12 and any subsequent amendment to this Plan, the number of Shares reserved for issuance and which will be available for issuance pursuant to Awards granted under this Plan will be equal to a number that:

The aggregate maximum number of Shares available under the Plan may be used for any type of Award. Subject to the provisions and restrictions of this Plan, if any Award is exercised, cancelled, expired or otherwise terminated for any reason whatsoever, the number of Shares in respect of which Award is exercised, cancelled, expired or otherwise terminated for any reason whatsoever, as the case may be, will ipso facto again be immediately available for purchase pursuant to Awards granted under this Plan.

All grants of Awards under this Plan will be evidenced by Award Agreements. Award Agreements will be subject to the applicable provisions of this Plan and will contain such provisions as are required by this Plan and any other provisions that the Board may direct. Any one officer of the Corporation is authorized and empowered to execute and deliver, for and on behalf of the Corporation, an Award Agreement to each Participant granted an Award pursuant to this Plan.

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No assignment or transfer of Awards, whether voluntary, involuntary, by operation of law or otherwise, vests any interest or right in such Awards whatsoever in any assignee or transferee (except that, if, and for so long as the Shares are listed on the TSX, a Participant may transfer Awards to Permitted Assigns in a manner consistent with applicable tax and securities laws) and immediately upon any assignment or transfer, or any attempt to make the same, such Awards will terminate and be of no further force or effect. If any Participant has transferred Awards to a corporation pursuant to this Section 3.7, such Awards will terminate and be of no further force or effect if at any time the transferor should cease to own all of the issued shares of such corporation.

If, and for so long as the Shares are listed on the TSX, grants of Awards may be made to Permitted Assigns of Employees, Directors and Consultants and may be transferred by Employees, Directors and Consultants to a Permitted Assign of an Employee, Director or Consultant as applicable, except for U.S. Taxpayers, if transfer to a Permitted Assign would be prohibited by Section 409A of the Code. In any such case, the provisions of ARTICLE 10 shall apply to the Award as if the Award was held by the Employee, Director or Consultant rather than such person’s Permitted Assign.

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In the event of the death of the Permitted Assign, the Award shall be automatically transferred to the Employee, Director or Consultant who effected the transfer of the Award to the deceased Permitted Assign.

ARTICLE 4

GRANT OF RESTRICTED SHARE UNITS

If, and for so long as (i) the Corporation is a Tier 1 issuer on the TSXV, (ii) the Shares are listed on the Toronto Stock Exchange, or (iii) the prior approval of the of the stock exchange on which the Shares are listed for trading is obtained, the Board may, from time to time, subject to the provisions of this Plan and such other terms and conditions as the Board may prescribe, grant RSUs to any Participant. The number of RSUs to be credited to each Participant’s account shall be computed by dividing (a) the Award Value, by (b) the Market Price of a Share on the day immediately preceding the Grant Date, with fractions rounded down to the nearest whole number.

The Board shall have the authority to condition the grant of RSUs upon the attainment of specified Performance Goals, or such other factors (which may vary as between awards of RSUs) as the Board may determine in its sole discretion.

The Board shall have the authority to determine at the time of grant, in its sole discretion, the duration of the vesting period and other vesting terms applicable to the grant of RSUs, provided that no RSU granted shall vest and be payable after December 31 of the third calendar year following the year of service for which the RSU was granted.

Unless otherwise specified in the Award Agreement, as soon as practicable following the expiry of the applicable vesting period, or at such later date as may be determined by the Board in its sole discretion at the time of grant, a share certificate representing the Shares issuable pursuant to the RSUs shall be registered in the name of the Participant or as the Participant may direct, subject to applicable securities laws.

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ARTICLE 5

PERFORMANCE SHARE UNITS

If, and for so long as (i) the Corporation is a Tier 1 issuer on the TSXV, (ii) the Shares are listed on the Toronto Stock Exchange, or (iii) the prior approval of the of the stock exchange on which the Shares are listed for trading is obtained, the Board may, from time to time, subject to the provisions of this Plan and such other terms and conditions as the Board may prescribe, grant PSUs to any Participant. Each PSU will consist of a right to receive a Share upon the achievement of such Performance Goals during such performance periods as the Board will establish. The number of PSUs to be credited to each Participant’s account shall be computed by dividing (a) the Award Value, by (b) the Market Price of a Share on the day immediately preceding the Grant Date, with fractions rounded down to the nearest whole number.

Subject to the terms of the Plan, the Performance Goals to be achieved during any performance period, the length of any performance period, the amount of any PSU granted, the termination of a Participant’s employment and the amount of any payment or transfer to be made pursuant to any PSU will be determined by the Board and by the other terms and conditions of any PSU, all as set forth in the applicable Award Agreement.

The Board will issue Performance Goals prior to the commencement of the performance period to which such Performance Goals pertain. The Performance Goals may be based upon the achievement of corporation-wide, divisional or individual goals, or any other basis determined by the Board. The Board may modify the Performance Goals as necessary to align them with the Corporation’s corporate objectives if there is a subsequent material change in the Corporation’s business, operations or capital or corporate structure. The Performance Goals may include a threshold level of performance below which no payment will be made (or no vesting will occur), levels of performance at which specified payments will be made (or specified vesting will occur), and a maximum level of performance above which no additional payment will be made (or at which full vesting will occur).

Unless otherwise specified in the Award Agreement, as soon as practicable following the expiry of the applicable vesting period, or at such later date as may be determined by the Board in its sole discretion at the time of grant, a share certificate representing the Shares issuable pursuant to the PSUs shall be registered in the name of the Participant or as the Participant may direct, subject to applicable securities laws.

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ARTICLE 6

RESTRICTED SHARES

If, and for so long as (i) the Corporation is a Tier 1 issuer on the TSXV, (ii) the Shares are listed on the Toronto Stock Exchange, or (iii) the prior approval of the of the stock exchange on which the Shares are listed for trading is obtained, the Board may, from time to time, subject to the provisions of this Plan and such other terms and conditions as the Board may prescribe, grant Restricted Shares to any Participant. The terms and conditions of each Restricted Shares grant shall be evidenced by an Award Agreement, which agreements need not be identical. The number of Restricted Shares to be credited to each Participant’s account shall be computed by dividing (a) the Award Value, by (b) the Market Price of a Share on the day immediately preceding the Grant Date, with fractions rounded down to the nearest whole number.

Subject to the restrictions set forth in Section 10.2, except as otherwise set forth in the applicable Award Agreement, the Participant shall generally have the rights and privileges of a shareholder as to such Restricted Shares, including the right to vote such Restricted Shares. Unless otherwise set forth in a Participant’s Award Agreement, cash dividends and stock dividends, if any, with respect to the Restricted Shares shall be withheld by the Corporation for the Participant’s account, and shall be subject to forfeiture until released, in each case, to be released at the same time and in the same proportion as the lapse of restrictions on the Restricted Shares to which such dividends relate. Except as otherwise determined by the Board, no interest will accrue or be paid on the amount of any dividends withheld.

In addition to any other restrictions set forth in a Participant’s Award Agreement, until such time that the Restricted Period for the Restricted Shares has lapsed pursuant to the terms of the Award Agreement, which Restricted Period the Board may in its sole discretion accelerate at any time, the Participant shall not be permitted to sell, transfer, pledge, or otherwise encumber the Restricted Shares. Notwithstanding anything contained herein to the contrary, the Board shall have the authority to remove any or all of the restrictions on the Restricted Shares whenever it may determine that, by reason of changes in applicable laws or other changes in circumstances arising after the date of the Restricted Shares Award, such action is appropriate.

Except as may otherwise be provided by applicable laws and regulations or in the applicable Award Agreement, in the event of a Participant’s “separation from service” (within the meaning of Section 409A of the Code) with the Corporation or any of the Subsidiaries for any reason prior to the time that the Restricted Period for the Participant’s Restricted Shares has lapsed, as soon as practicable following such Separation from Service, the Corporation shall repurchase from the Participant, and the Participant shall sell, all of such Participant’s Restricted Shares for which the Restricted Period has not lapsed at a purchase price equal to the cash amount, if any, paid by the Participant for the Restricted Shares, or if no cash amount was paid by the Participant for the Restricted Shares, such Restricted Shares shall be forfeited by the Participant to the Corporation for no consideration as of the date of such separation from service.

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ARTICLE 7

GRANT OF DEFERRED SHARE UNITS

If, and for so long as (i) the Corporation is a Tier 1 issuer on the TSXV, (ii) the Shares are listed on the Toronto Stock Exchange, or (iii) the prior approval of the of the stock exchange on which the Shares are listed for trading is obtained, the Board may, from time to time, subject to the provisions of this Plan and such other terms and conditions as the Board may prescribe, grant Deferred Share Units to any Participant; provided, however, to the extent required by applicable law (including, but not limited to, Section 409A of the Code), if any Participant is allowed an election to receive DSUs in lieu of other compensation, such election must be made in writing prior to the start of the calendar year during which services will be performed for which the compensation relates, or such later date as permitted in accordance with applicable law, including, but not limited to, Section 409A of the Code and the regulations thereunder. The number of DSUs to be credited to each Participant’s account shall be computed by dividing (a) the Award Value, by (b) the Market Price of a Share on the day immediately preceding the Grant Date, with fractions rounded down to the nearest whole number.

All Deferred Share Units received by a Participant shall be credited to an account maintained for the Participant on the books of the Corporation, as of the Date of Grant. The award of Deferred Share Units for a calendar year to a Participant shall be evidenced by an Award Agreement.

DSUs shall be settled on the date established in the Award Agreement (the “ Settlement Date ”); provided, however that in no event shall a DSU Award be settled prior to the date of the applicable Participant’s Separation from Service. If the Award Agreement does not establish a date for the settlement of the DSUs, then the Settlement Date shall be the date of Separation from Service, subject to the delay that may be required under Section 13.9 below. On the Settlement Date for any DSU:

ARTICLE 8

OTHER SHARE-BASED AWARDS

The Board may, from time to time, subject to the prior approval of the TSX-V, if applicable, the provisions of this Plan and such other terms and conditions as the Board may prescribe, grant Other Share-Based Awards to any Participant. Each Other Share-Based Award will consist of a right (1) which is other than an Award or right described in Article 4, 5, 6 or 7 above and (2)

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which is denominated or payable in, valued in whole or in part by reference to, or otherwise based on or related to, Shares (including, without limitation, securities convertible into Shares) as are deemed by the Board to be consistent with the purposes of the Plan; provided, however, that such right will comply with applicable law. Subject to the terms of the Plan and any applicable Award Agreement, the Board will determine the terms and conditions of Other Share-Based Awards. Shares or other securities delivered pursuant to a purchase right granted under this Section 8.1 will be purchased for such consideration, which may be paid by such method or methods and in such form or forms, including, without limitation, cash, Shares, other securities, other Awards, other property, or any combination thereof, as the Board will determine.

ARTICLE 9

BONUS SHARES

The Board may, from time to time, subject to the provisions of this Plan and such other terms and conditions as the Board may prescribe, grant fully paid and non-assessable Bonus Shares to any Participant. The allocation of the Bonus Shares among the Participants shall be determined by the Board of Directors at the time that the Bonus Shares are qualified for issuance and shall be evidenced by an Award Agreement.

ARTICLE 10

TERMINATION OF EMPLOYMENT OR SERVICES

If a Participant dies or becomes Disabled while an Employee, Director or Consultant:

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Notwithstanding the provisions of Sections 10.1 and 10.2, the Board may, in its discretion, at any time prior to or following the events contemplated in such Sections, permit the acceleration of vesting (or Restricted Period) of any or all Awards, all in the manner and on the terms as may be authorized by the Board.

ARTICLE 11

CHANGE IN CONTROL

The Board shall have the right to determine that any unvested or unearned Bonus Shares, Restricted Share Units, Deferred Share Units, Performance Share Units or Other Share-Based Awards or Restricted Shares subject to a Restricted Period outstanding immediately prior to the occurrence of a Change in Control shall become fully vested or earned or free of restriction upon the occurrence of such Change in Control. The Board may also determine that any vested or earned Bonus Shares, Restricted Share Units, Deferred Share Units, Performance Share Units or Other Share-Based Awards shall be cashed out at the Market Price as of the date such Change in Control is deemed to have occurred, or as of such other date as the Board may determine prior to the Change in Control. Further, the Board shall have the right to provide for the conversion or exchange of any Bonus Shares, Restricted Share Unit, Deferred Share Unit, Performance Share Unit or Other Share-Based Award into or for rights or other securities in any entity participating in or resulting from the Change in Control.

ARTICLE 12

SHARE CAPITAL ADJUSTMENTS

The existence of any Awards does not affect in any way the right or power of the Corporation or its shareholders to make, authorize or determine any adjustment, recapitalization, reorganization or any other change in the Corporation’s capital structure or its business, or any amalgamation, combination, arrangement, merger or consolidation involving the Corporation, to create or issue any bonds, debentures, Shares or other securities of the Corporation or to determine the rights and conditions attaching thereto, to effect the dissolution or liquidation of the Corporation or any

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sale or transfer of all or any part of its assets or business, or to effect any other corporate act or proceeding, whether of a similar character or otherwise, whether or not any such action referred to in this Section would have an adverse effect on this Plan or on any Award granted hereunder.

Should the Corporation effect a subdivision or consolidation of Shares or any similar capital reorganization or a payment of a stock dividend (other than a stock dividend that is in lieu of a cash dividend), or should any other change be made in the capitalization of the Corporation that does not constitute a Change in Control and that would warrant the amendment or replacement of any existing Awards in order to adjust the number of Shares that may be acquired on the vesting of outstanding Awards and/or the terms of any Award in order to preserve proportionately the rights and obligations of the Participants holding such Awards, the Board will, subject to the prior approval of the Exchange, authorize such steps to be taken as it may consider to be equitable and appropriate to that end.

In the event of an amalgamation, combination, arrangement, merger or other transaction or reorganization involving the Corporation and occurring by exchange of Shares, by sale or lease of assets or otherwise, that does not constitute a Change in Control and that warrants the amendment or replacement of any existing Awards in order to adjust: (a) the number of Shares that may be acquired on the vesting of outstanding Awards and/or (b) the terms of any Award in order to preserve proportionately the rights and obligations of the Participants holding such Awards, the Board will, subject to the prior approval of the Exchange, authorize such steps to be taken as it may consider to be equitable and appropriate to that end.

Where the Board determines that the steps provided in Sections 12.2 and 12.3 would not preserve proportionately the rights, value and obligations of the Participants holding such Awards in the circumstances or otherwise determines that it is appropriate the Board may permit the immediate vesting of any unvested Awards and immediate lapse of any Restricted Period.

Except as expressly provided in this ARTICLE 12, neither the issue by the Corporation of shares of any class or securities convertible into or exchangeable for shares of any class, nor the conversion or exchange of such shares or securities, affects, and no adjustment by reason thereof is to be made with respect to the number of Shares that may be acquired as a result of a grant of Awards.

No fractional Shares will be issued pursuant to an Award. Accordingly, if, as a result of any adjustment under Section 12.2, 12.3 or dividend equivalent, a Participant would become entitled to a fractional Share, the Participant has the right to acquire only the adjusted number of full Shares and no payment or other adjustment will be made with respect to the fractional Shares, which shall be disregarded.

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ARTICLE 13

MISCELLANEOUS PROVISIONS

The Corporation is not obligated to grant any Awards, issue any Shares or other securities, make any payments or take any other action if, in the opinion of the Board, in its sole discretion, such action would constitute a violation by a Participant, Director or the Corporation of any provision of any applicable statutory or regulatory enactment of any government or government agency or the requirements of any stock exchange upon which the Shares may then be listed.

Except as otherwise provided in this Plan, Awards previously granted under this Plan are not affected by any change in the relationship between, or ownership of, the Corporation and an Affiliate. For greater certainty, all grants of Awards remain are not affected by reason only that, at any time, an Affiliate ceases to be an Affiliate.

The granting or vesting or lapse of the Restricted Period of each Award under this Plan is subject to the condition that if at any time the Board determines, in its discretion, that the satisfaction of withholding tax or other withholding liabilities is necessary or desirable in respect of such grant, vesting or lapse of the Restricted Period, such action is not effective unless such withholding has been effected to the satisfaction of the Board. In such circumstances, the Board may require that a Participant pay to the Corporation such amount as the Corporation or an Affiliate is obliged to remit to the relevant taxing authority in respect of the granting or vesting or lapse of the Restricted Period of the Award. Any such additional payment is due no later than the date on which any amount with respect to the Award is required to be remitted to the relevant tax authority by the Corporation or an Affiliate, as the case may be.

No Participant has any claim or right to be granted an Award and the granting of any Award is not to be construed as giving a Participant a right to remain as an employee, consultant or director of the Corporation or an Affiliate. No Participant has any rights as a shareholder of the Corporation in respect of Shares issuable pursuant to any Award until the allotment and issuance to such Participant, or as such Participant may direct, of certificates representing such Shares.

The Board shall have the right to grant other incentive awards based upon Shares under this Plan to Participants in accordance with applicable laws and regulations and subject to regulatory approval, including without limitation the approval of the Exchange (to the extent the Corporation has any securities listed on the particular exchange), having such terms and conditions as the Board may determine, including without limitation the grant of Shares based upon certain conditions and the grant of securities convertible into Shares.

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If an Award expires during, or within five business days after, a trading black-out period imposed by the Corporation to restrict trades in the Corporation’s securities, then, notwithstanding any other provision of this Plan, the Award shall expire ten business days after the trading black-out period is lifted by the Corporation.

The Board may, without notice or shareholder approval, terminate the Plan on or after the date upon which no Awards remain outstanding.

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Any amendment that would cause an Award held by a U.S. Taxpayer to fail to comply with Section 409A of the Code shall be null and void ab initio .

This Plan will be construed and interpreted to be exempt from, or where not so exempt, to comply with Section 409A of the Code to the extent required to preserve the intended tax consequences of this Plan. The Corporation reserves the right to amend this Plan to the extent it reasonably determines is necessary in order to preserve the intended tax consequences of this Plan in light of Section 409A of the Code and any regulations or guidance under that section. In no event will the Corporation be responsible if Awards under this Plan result in adverse tax consequences to a U.S. Taxpayer under Section 409A of the Code. Notwithstanding any provisions of the Plan to the contrary, in the case of any “specified employee” within the meaning of Section 409A of the Code who is a U.S. Taxpayer, distributions of non-qualified deferred compensation under Section 409A of the Code made in connection with a “separation from service” within the meaning set forth in Section 409A of the Code may not be made prior to the date which is 6 months after the date of separation from service (or, if earlier, the date of death of the U.S. Taxpayer). Any amounts subject to a delay in payment pursuant to the preceding sentence shall be paid as soon practicable following such 6-month anniversary of such separation from service.

If a Participant, in connection with the acquisition of Restricted Shares under the Plan, is permitted under the terms of the Award Agreement to make the election permitted under Section 83(b) of the Code (i.e., an election to include in gross income in the year of transfer the amounts specified in Section 83(b) of the Code notwithstanding the continuing transfer restrictions) and the Participant makes such an election, the Participant shall notify the Corporation of such election within ten (10) days of filing notice of the election with the Internal Revenue Service, in addition to any filing and notification required pursuant to regulations issued under Section 83(b) of the Code.

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Every member of the Board will at all times be indemnified and saved harmless by the Corporation from and against all costs, charges and expenses whatsoever including any income tax liability arising from any such indemnification, that such member may sustain or incur by reason of any action, suit or proceeding, taken or threatened against the member, otherwise than by the Corporation, for or in respect of any act done or omitted by the member in respect of this Plan, such costs, charges and expenses to include any amount paid to settle such action, suit or proceeding or in satisfaction of any judgment rendered therein.

The participation of any Participant in the Plan is entirely voluntary and not obligatory and shall not be interpreted as conferring upon such Participant any rights or privileges other than those rights and privileges expressly provided in the Plan. In particular, participation in the Plan does not constitute a condition of employment or engagement nor a commitment on the part of the Corporation to ensure the continued employment or engagement of such Participant. The Plan does not provide any guarantee against any loss which may result from fluctuations in the market value of the Shares. The Corporation does not assume responsibility for the income or other tax consequences for the Participants and Directors and they are advised to consult with their own tax advisors.

With respect to Participants who reside or work outside Canada and the United States, the Board may, in its sole discretion, amend, or otherwise modify, without shareholder approval, the terms of the Plan or Awards with respect to such Participants in order to conform such terms with the provisions of local law, and the Board may, where appropriate, establish one or more sub-plans to reflect such amended or otherwise modified provisions.

This Plan becomes effective on June 27, 2013, being the date on which the Plan was approved by the shareholders of the Corporation.

This Plan and all matters to which reference is made herein shall be governed by and interpreted in accordance with the laws of the Province of Québec and the federal laws of Canada applicable therein.

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SCHEDULE A

Award Agreement

Acasti Pharma Inc. (“ Us ” or “ Our ”) hereby grants the following Award(s) to you subject to the terms and conditions of this Award Agreement (the “ Agreement ”), together with the provisions of Our Equity Incentive Plan (the “ Plan ”) in which you become a “Participant”, dated — , 2013, all the terms of which are hereby incorporated into this Agreement:

I have read the foregoing Agreement and hereby accept the Award in accordance with and subject to the terms and conditions of the Agreement and the Plan. [I understand that I may review the complete text of the Plan on line at [ — ], or by contacting either my Human Resources representative or the Office of the Corporate Secretary.] I agree to be bound by the terms and conditions of the Plan governing the Award.

Exhibit 4.5

STOCK OPTION PLAN FOR MEMBERS OF THE BOARD OF DIRECTORS,

MANAGEMENT, EMPLOYEES AND CONSULTANTS OF

ACASTI PHARMA INC.

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Notwithstanding anything contained to the contrary in this Plan, except for section 10.3 above, or in any resolution of the Board in implementation thereof:

Notwithstanding the provisions of this Section 15, should changes be required to the Plan by any regulatory authority of any jurisdiction to which this Plan or the Corporation now is or hereafter becomes subject, such changes shall be made to the Plan as are necessary to conform with such requirements and, if such changes are approved by the Board, the Plan, as amended, shall be filed with the records of the Corporation and shall remain in full force and effect in its amended form as of and from the date of its adoption by the Board.

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resolution. However, without the written consent of the option holders, amending or terminating the Plan must not in any way affect the conditions of options already granted under the Plan, provided these options have not already been exercised, unless the option holders’ rights have expired, been exercised in whole or option holders consent to the changes.

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