Exhibit 99.1

EXECUTION VERSION

UNDERWRITING AGREEMENT

November 27, 2013

Euro Pacific Canada Inc.

As Representative of the several Underwriters

130 King Street West, Suite 2820

Toronto, ON M5X 1A9

Dear Sir:

Euro Pacific Canada Inc. (the “Representative”) and National Securities Corporation (collectively with the Representative, the “Underwriters” and each individually, an “Underwriter”) understand that, subject to the terms and conditions stated herein, Acasti Pharma Inc., a corporation incorporated under the Business Corporations Act (Québec) (the “Company”), proposes to issue and sell to the Underwriters an aggregate of 16,000,000 units of the Company (each, a “Unit”, and collectively, the “Firm Units”). Each Unit shall be comprised of a fixed combination of one (1) Class A share in the capital of the Company (a “Unit Share”) and one (1) common share purchase warrant (each, a “Warrant”). Each Warrant shall entitle its holder to acquire one Class A share in the capital of the Company (a “Warrant Share”) at a price of US$1.50 for a period of five (5) years following the First Closing Date (as defined in Section 2(3)). The Warrants shall be created and issued pursuant to a warrant indenture (the “Warrant Indenture”) to be entered into as of the First Closing Date between the Company and Computershare Trust Company of Canada (the “Warrant Agent”). The Class A shares in the capital of the Company are generally referred to herein as “Common Shares”.

Based on the foregoing, and subject to the terms and conditions contained in this Underwriting Agreement (the “Agreement”), the Underwriters severally and not jointly, in respect of their percentages set forth in Section 9 hereof, agree to purchase from the Company, and by its acceptance hereof, the Company agrees to sell to the Underwriters, all but not less than all of the Firm Units on the First Closing Date for a purchase price of US$1.25 (the “Offering Price”) per Firm Unit, being an aggregate purchase price of US$20,000,000 against delivery of such Firm Units.

In addition, the Company proposes to grant to the Underwriters, in respect of their percentages set forth in Section 9 hereof, an option (the “Over-Allotment Option”), exercisable in whole or in part at any time prior to 5:00 p.m. (Montréal time) on the day that is the 30th day following the First Closing Date, to purchase up to an additional 2,400,000 Units (the “Additional Units” and collectively with the Firm Units, the “Offered Units”) representing up to 15.0% of the aggregate number of Firm Units, at the Offering Price and upon the terms and conditions set forth herein for the purposes of covering over-allotments and for market stabilization purposes. The aforesaid Offered Units, Unit Shares, Warrants and Warrant Shares are collectively referred to herein as the “Securities”. The Securities shall have the material attributes described in and contemplated by the Prospectuses which are referred to below.

(1) The Company has prepared and filed with the securities regulatory authorities (the “Canadian Commissions”) in each of the provinces of British Columbia, Alberta, Manitoba, Ontario and Québec (collectively, the “Qualifying Jurisdictions”) a preliminary short form base shelf prospectus dated October 16, 2013 relating to the distribution of up to US$150,000,000 of Common Shares, warrants, and units of the Company (the “Shelf Securities”) pursuant to applicable securities laws of the Qualifying Jurisdictions and the respective rules, regulations, blanket rulings, orders and notices made thereunder and the local, uniform, national and multilateral instruments and policies adopted by the Canadian Commissions in the Qualifying Jurisdictions (collectively, as applied and interpreted, the “Canadian Securities Laws”) and in accordance with Multilateral Instrument 11-102 Passport System (“MI 11-102”) and National Policy 11-202 Process for Prospectus Reviews in Multiple Jurisdictions (“NP 11-202”, and together with MI 11-102, the “Passport System”). Such preliminary short form base shelf prospectus relating to the distribution of the Shelf Securities, including any documents incorporated by reference therein and any supplements or amendments thereto, is herein called the “Canadian Preliminary Base Prospectus.” The Company has prepared and filed the Canadian Preliminary Base Prospectus pursuant to National Instrument 44-101 – Short Form Prospectus Distributions and National Instrument 44-102 – Shelf Distributions, the “Shelf Procedures”. The Autorité des marchés financiers (Québec) (the “Principal Regulator”) has issued a receipt for the Canadian Preliminary Base Prospectus and the Company has satisfied the conditions in MI 11-102 to the deemed issuance of a receipt by the Canadian Commissions for the Canadian Preliminary Base Prospectus in each of the other Qualifying Jurisdictions.

(2) The Company has also prepared and filed with the United States Securities and Exchange Commission (the “SEC”) pursuant to the Canada/United States Multi-Jurisdictional Disclosure System adopted by the Canadian Commissions and the SEC (the “MJDS”), a registration statement on Form F-10 (Registration No. 333-191907) for the registration of the offering of the Shelf Securities under the United States Securities Act of 1933, as amended (together with the rules and regulations promulgated thereunder, the “Securities Act”), including the final short form base shelf prospectus dated October 25, 2013 relating to the distribution of the Shelf Securities (including any documents incorporated therein by reference and any supplements or amendments thereto, the “Canadian Final Base Prospectus”), pursuant to the Shelf Procedures, omitting the Shelf Information (as hereinafter defined) in accordance with the rules and procedures set forth in NI 44-102 with such deletions therefrom and additions or changes thereto as are permitted or required by Form F-10 and the applicable rules and regulations of the SEC. The Company has also prepared and filed with the SEC an Appointment of Agent for Service of Process and Undertaking on Form F-X at the time of the filing of the registration statement on Form F-10 (the “Form F-X”).

(3) In addition, the Company (a) has prepared and filed with the SEC (i) a notice of clearance relating to the Canadian Final Base Prospectus issued by the Autorité des marchés financiers, the securities regulator in Quebec, Canada, for the U.S. Registration

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Statement on Form F-10 (the prospectus in the U.S. Registration Statement on Form F-10, including the documents incorporated by reference therein and any supplements or amendments thereto when it became effective pursuant to Rule 467(b) under the U.S. Securities Act on October 28, 2013 (the “Effective Date”), is referred to herein as the “U.S. Base Prospectus”), (ii) the preliminary prospectus supplement dated November 26, 2013 specifically relating to the Offered Units, pursuant to General Instruction II.L of Form F-10, including the documents incorporated by reference therein (together with the U.S. Base Prospectus is hereinafter referred to as the “U.S. Preliminary Prospectus” and (b) will prepare and file, as promptly as possible and in any event (i) not later than 11:00 p.m. (Montréal time) on November 27, 2013, with the Canadian Commissions in the Qualifying Jurisdictions, in accordance with the Shelf Procedures, a prospectus supplement setting forth the Shelf Information (including any documents incorporated therein by reference and any supplements or amendments thereto, the “Canadian Prospectus Supplement”, and together with the Canadian Final Base Prospectus, the “Canadian Prospectus”), and (ii) within one business day of such filing with the Canadian Commissions, with the SEC pursuant to General Instruction II.L, of Form F-10, the Canadian Prospectus Supplement (with such deletions therefrom and additions thereto as are permitted or required by Form F-10 and the applicable rules and regulations of the SEC) (the “U.S. Prospectus Supplement”, and together with the U.S. Base Prospectus, the “U.S. Prospectus”). The information, if any, included in the Canadian Prospectus Supplement that is omitted from the Canadian Final Base Prospectus for which a final receipt has been obtained from the Canadian Commissions, but that is deemed under the Shelf Procedures to be incorporated by reference into the Canadian Final Base Prospectus as of the date of the Canadian Prospectus Supplement, is referred to herein as the “Shelf Information.”

(4) The registration statement on Form F-10, including any amendment thereof on or prior to the Effective Date and including the exhibits thereto, the documents incorporated or deemed to be incorporated by reference therein and any information deemed to be a part thereof at the Effective Date for purposes of Section 10 under the Securities Act and including the Shelf Information, is herein called the “Registration Statement.”

(5) The Canadian Preliminary Base Prospectus and the U.S. Preliminary Prospectus, including the documents incorporated by reference therein and any supplements or amendments thereto that omit the Shelf Information are herein collectively sometimes referred to as the “Preliminary Prospectuses.” The U.S. Prospectus and the Canadian Prospectus are hereinafter collectively sometimes referred to as the “Prospectuses.” The U.S. Prospectus Supplement and the Canadian Prospectus Supplement are hereinafter collectively sometimes referred to as the “Prospectus Supplements.”

(6) Any amendment or supplement to the U.S. Prospectus or the Canadian Prospectus (including any document incorporated by reference therein), that may be filed by or on behalf of the Company with the Canadian Commissions in the Qualifying Jurisdictions or with the SEC after the Canadian Prospectus Supplement and the U.S. Prospectus Supplement have been filed and prior to the expiry of the period of distribution of the Offered Units, is referred to herein collectively as the “Supplementary Material.”

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(7) As used herein, the “Applicable Time” is 9:00 a.m. (New York time) on November 27, 2013. As used herein, a “free writing prospectus” has the meaning set forth in Rule 405 under the Securities Act, and a “Time of Sale Prospectus” means the U.S. Preliminary Prospectus together with the information and the free writing prospectuses, if any, and each “road show” (as defined in Rule 433 under the Securities Act), if any, related to the offering of the Offered Units contemplated hereby that is a “written communication” (as defined in Rule 405 under the Securities Act) (each such road show, a “Road Show”) identified in Schedule A hereto.

(8) As used herein, the terms “Registration Statement,” “Preliminary Prospectuses,” “Time of Sale Prospectus” and “Prospectuses” shall include the documents incorporated and deemed to be incorporated by reference therein (the “Incorporated Documents”), including, unless the context otherwise requires, the documents, if any, filed as exhibits to such Incorporated Documents.

(9) All references in this Agreement to the Registration Statement, the U.S. Preliminary Prospectus or the U.S. Prospectus shall include any copy thereof filed with the SEC pursuant to its Electronic Data Gathering, Analysis and Retrieval System (“EDGAR”). All references in this Agreement to Financial Statements (as defined in Section 3(o)) and schedules and other information which are “contained,” “included” or “stated” in the Registration Statement, the Time of Sale Prospectus or the U.S. Prospectus (and all other references of like import) shall be deemed to mean and include all such Financial Statements and schedules and other information which is or is deemed to be incorporated by reference in the Registration Statement, the Time of Sale Prospectus or the U.S. Prospectus, as the case may be; and all references in this Agreement to amendments or supplements to the Registration Statement, the Time of Sale Prospectus or the U.S. Prospectus, as the case may be, shall be deemed to mean and include the filing of any document under the United States Securities Exchange Act of 1934, as amended (together with the rules and regulations promulgated thereunder, the “Exchange Act”) or otherwise that is or is deemed to be incorporated by reference in the Registration Statement, the Time of Sale Prospectus or the U.S. Prospectus, as the case may be.

(10) As used herein, “business day” shall mean a day on which each of the NASDAQ Capital Market (“NASDAQ”) and the TSX Venture Exchange (“TSXV”) is open for trading. The terms “herein,” “hereof,” “hereto,” “hereinafter” and similar terms, as used in this Agreement, shall in each case refer to this Agreement as a whole and not to any particular section, paragraph, sentence or other subdivision of this Agreement. The term “or,” as used herein, is not exclusive.

(11) The Underwriters shall offer the Offered Units for sale to the public directly and through other duly registered investment dealers and brokers in the Qualifying Jurisdictions and the United States only as permitted by applicable law and upon the terms and conditions set forth in the Prospectuses and this Agreement. The Underwriters agree that they will not, directly or indirectly, distribute the Registration Statement, the Time of Sale Prospectus, or the Prospectuses or publish any prospectus, circular, advertisement or other offering material in any jurisdiction other than the Qualifying Jurisdictions or such states of the United States in which the Securities are duly qualified under United States

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federal and applicable United States state securities laws, in such manner as to require registration of the Securities or the filing of a prospectus or any similar document with respect to the Securities by the Company therein or subject the Company to ongoing periodic reporting obligations in such jurisdiction pursuant to the securities laws of such jurisdiction. The Underwriters agree that each of the Underwriters that is not registered as a broker-dealer under Section 15 of the Exchange Act, will not offer or sell any Offered Units in, or to persons who are nationals or residents of, the United States other than through one of its United States registered broker-dealer affiliates or otherwise in compliance with Rule 15a-6 under the Exchange Act. Sales of the Offered Units in the Qualifying Jurisdictions may be made only by or through a dealer appropriately registered under applicable Canadian Securities Laws or in circumstances where an exemption from the Canadian registered dealer requirements is available. Notwithstanding the foregoing provisions of this paragraph, an Underwriter will not be liable to the Company under this Agreement with respect to a default by another Underwriter under this paragraph.

The Company hereby confirms its agreement with the Underwriters concerning the purchase and sale of the Offered Units as follows:

(1) Public Offering of the Offered Units. The Representative hereby advises the Company that the Underwriters intend to offer for sale to the public, initially on the terms set forth in the Time of Sale Prospectus and each Prospectus, their respective portions of the Offered Units as soon after this Agreement has been executed as the Representative, in its sole judgment, has determined is advisable and practicable. Following the First Closing Date, after the Underwriters have made a reasonable effort to sell all of the Offered Units at the Offering Price, the purchase price of the Offered Units may be decreased by the Underwriters and may be further changed from time to time to an amount not greater than the Offering Price, and the compensation realized by the Underwriters will be decreased by the amount that the aggregate price paid by purchasers for the Offered Units is less than the gross proceeds paid by the Underwriters to the Company.

(2) Underwriters’ Commission. In consideration of the Agreement of the Underwriters to purchase the Offered Units and to offer them to the public, the Company agrees to pay to the Underwriters (a) at the First Closing Date (as defined in Section 2(3)) an underwriting fee equal to 3% of the gross proceeds from the sale of the Firm Units to those purchasers agreed to by the Representative and the Company, and 6% of the gross proceeds from the sale of the Firm Units to all other purchasers; and (b) at the Option Closing Date (as defined in Section 2(4)) an underwriting fee equal to 6% of the gross proceeds from the sale of the Additional Units (the “Underwriters’ Commission”). The Underwriters’ Commission may be deducted by the Underwriters from the proceeds of sale of the Firm Units on the First Closing Date or the proceeds of sale of the Additional Units on the Option Closing Date, as applicable. In addition, the Company agrees to pay to the Underwriters, and in the manner specified by the Representative, all fees, disbursements and expenses incurred by the Underwriters in accordance with the provisions in Section 5 hereof.

(3) The First Closing Date in respect of the Firm Units. Payment of the Offering Price for the Firm Units shall be made to the Company by wire transfer against delivery of the Unit

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Shares and the Warrants underlying the Firm Units to the Representative on behalf of the Underwriters, through the facilities of CDS Clearing and Depository Services Inc. (“CDS”) and The Depository Trust Company (“DTC”) designated by the Underwriters, and such payment and delivery shall be made at 8:30 a.m. (Montréal time), on December 3, 2013 (the “First Closing Date”) (unless another time shall be agreed to by the Representative and the Company or unless postponed in accordance with the provisions of Section 9 hereof). The Unit Shares and Warrants underlying the Firm Units shall be registered in such names and in such denominations as specified by the Representative on behalf of the Underwriters. It is understood that the Representative has been authorized, for its own account and the accounts of the non-defaulting Underwriters, to accept delivery of and receipt for, and make payment of the Offering Price for, the Firm Units and any Additional Units the Underwriters have agreed to purchase (subject to such adjustment as the Representative may determine to eliminate fractional shares and subject to adjustment in accordance with Section 9 hereof). The Representative, individually and not as the Representative of the Underwriters, may (but shall not be obligated to) make payment for any Offered Units to be purchased by any Underwriter whose funds shall not have been received by the Representative by the First Closing Date or the applicable Option Closing Date (as defined in Section 2(4)), as the case may be, for the account of such Underwriter, but any such payment shall not relieve such Underwriter from any of its obligations under this Agreement.

(4) The Additional Units and the Option Closing Date. In addition, the Company hereby grants to the Underwriters the Over-Allotment Option to purchase, and upon the basis of the representations and warranties and subject to the terms and conditions set forth herein, the Underwriters shall have the right to purchase, severally and not jointly, from the Company, all or a portion of the Additional Units as may be necessary to cover over-allotments made in connection with the offering of the Offered Units, at the same Offering Price per Firm Unit to be paid by the Underwriters to the Company for the Firm Units. The Over-Allotment Option granted hereunder may be exercised at any time and from time to time in whole or in part until the day that is the 30th day following the First Closing Date upon notice by the Representative to the Company, which notice may be given at any time prior to 5:00 p.m. (Montréal time) on the day that is the 28th day from the First Closing Date (the “Notice of Exercise”). The Notice of Exercise shall set forth (i) the aggregate number of Additional Units as to which the Underwriters are exercising the option, (ii) the names and denominations in which the Unit Shares and the Warrants underlying the Additional Units are to be registered through the facilities of DTC and CDS, as applicable, and (iii) the time, date and place at which payment and delivery are to be made in respect of the Additional Units (which time and date may be simultaneous with, but not earlier than the First Closing Date; and in the event that such time and date are simultaneous with the First Closing Date, the term “First Closing Date” shall refer to the time and date of delivery of the Unit Shares and the Warrants underlying the Firm Units and such Additional Units through the facilities of DTC or CDS, as applicable. Any such time and date of delivery, if subsequent to the First Closing Date, is called an “Option Closing Date” and shall be determined by the Representative and shall not be earlier than two nor later than five full business days after the date of delivery of such Notice of Exercise. If any Additional Units are to be purchased, each Underwriter agrees, severally and not jointly, to purchase the number of Additional Units (subject to such adjustment as the Representative may determine to eliminate

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fractional shares) that bears the same proportion to the total number of Additional Units to be purchased as the number of Firm Units set forth opposite the name of such Underwriter in Section 9 hereof bears to the total number of Firm Units subject to adjustment in accordance with Section 9 hereof.

(5) Delivery of the Offered Units and Closing Mechanics. The Company shall deliver, or cause to be delivered, to the Representative for the accounts of the Underwriters the Unit Shares and Warrants underlying the Firm Units at the First Closing Date, against the irrevocable release of a wire transfer of immediately available funds for the amount of the Offering Price therefor. The Company shall also deliver, or cause to be delivered, to the Representative for the accounts of the Underwriters, the Unit Shares and Warrants underlying the Additional Units the Underwriters have agreed to purchase at the First Closing Date or the applicable Option Closing Date, as the case may be, against the irrevocable release of a wire transfer of immediately available funds for the amount of the Offering Price therefor. The Unit Shares and Warrants shall be registered in such names and denominations as the Representative shall have requested at least one full business day prior to the First Closing Date (or the applicable Option Closing Date, as the case may be). Deliveries of the documents described in Section 6 hereof with respect to the purchase of the Offered Units shall be made at the offices of Osler, Hoskin & Harcourt LLP in Montreal, Québec at 8:30 a.m. (Montréal Time), or at such other place as the Representative and the Company may agree, on the First Closing Date or the Option Closing Date, as the case may be. Time shall be of the essence, and delivery at the time and place specified in this Agreement is a further condition to the obligations of the Underwriters.

The Company hereby represents and warrants to each Underwriter, as of the date of this Agreement, as of the First Closing Date and as of each Option Closing Date, if any, and covenants with each Underwriter, as follows:

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In this Agreement, a reference to “knowledge” of the Company, means the knowledge of the executive officers of the Company or any officer who may be responsible for the subject matter at issue, in each case, after reasonable inquiry.

Any certificate signed by any officer on behalf of the Company and delivered to the Underwriters or counsel for the Underwriters in connection with the offering of the Offered Units shall be deemed to be a representation and warranty by the Company as to matters covered thereby to each Underwriter.

The Company acknowledges that the Underwriters and, for purposes of the opinions to be delivered pursuant to Section 7 hereof, counsel to the Company and counsel to the Underwriters will rely upon the accuracy and truthfulness of the foregoing representations and hereby consents to such reliance.

The Company further covenants and agrees with each Underwriter as follows:

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The Representative, on behalf of the Underwriters, may, in its sole discretion, waive in writing the performance by the Company of any one or more of the foregoing covenants or extend the time for their performance.

Whether or not the purchase and sale of the Offered Units pursuant to this Agreement is completed, the Company will pay all costs, expenses, fees and taxes incurred in connection with the purchase, sale and delivery of the Offered Units and the performance of its obligations hereunder and in connection with the transactions contemplated hereby, including without limitation, the following:

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including Canadian federal goods and services tax and provincial sales tax eligible in respect of any of the foregoing. All such expenses incurred by or on behalf of the Underwriters shall be payable by the Company within 30 days of the receipt of an invoice in respect thereof. Notwithstanding the foregoing, the fees and expenses payable by the Company to the Underwriters pursuant to subparagraphs (d) and (f) above shall not exceed USD$150,000 which includes a retainer of USD$50,000 that was delivered to United States counsel to the Underwriters. Except as provided in this Section 5, the Underwriters shall

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pay their own expenses, including the fees and disbursements of their counsel, transfer taxes on resale of any Securities by them, and any advertising expenses in connection with any offers of Securities that they may make following the First Closing Date.

The obligations of the Underwriters to purchase and pay for the Firm Units as provided herein on the First Closing Date and, with respect to the Additional Units, each Option Closing Date shall be subject to the accuracy of the representations and warranties on the part of the Company set forth in Section 3 as of the date hereof and as of the First Closing Date as though then made and, with respect to the Additional Units, as of each Option Closing Date as though then made, to the timely performance by the Company of its covenants and other obligations of the Company hereunder, and to each of the following additional conditions precedent:

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If any condition specified in this Section 6 is not satisfied when and as required to be satisfied, this Agreement may be terminated by the Representative by notice to the Company at any time on or prior to the First Closing Date and, with respect to the Additional Units, at any time on or prior to the applicable Option Closing Date, which termination shall be without liability on the part of any party to any other party, except that Section 5, Section 6, Section 10 and Section 11 shall at all times be effective and shall survive such termination.

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(1) Each Underwriter, severally and not jointly, covenants with the Company, after the First Closing Date, the Underwriters will (a) use their reasonable best efforts to complete the distribution of the Offered Units and, if applicable, the Additional Units as promptly as possible and (b) give prompt written notice to the Company or its counsel when, in the opinion of the Underwriters, they have completed distribution of the Firm Units and, if applicable, the Additional Units, and, within 30 days after completion of the distribution, will provide the Company or its counsel in writing, with a breakdown of the number of Offered Units distributed in each of the Qualifying Jurisdictions and in the United States where that breakdown is required by a Canadian Commission or the SEC, as the case may be, for the purpose of calculating fees payable to, or making filings with, that Canadian Commission or the SEC, as the case may be.

(2) No Underwriter shall be liable to the Company under this Section 7 with respect to a default by any of the other Underwriters.

(3) Each Underwriter, severally and not jointly, covenants with the Company not to take any action that would result in the Company being required to file with the SEC pursuant to Rule 433 (d) under the Securities Act a free writing prospectus prepared by or on behalf such Underwriter that otherwise would not be required to be filed by the Company thereunder but for the action of the Underwriter.

(1) Prior to the purchase of the Firm Units by the Underwriters on the First Closing Date or, in the case of the Additional Units prior to the Option Closing Date, this Agreement may be terminated by the Representative on behalf of the Underwriters by written notice to that effect given to the Company if at any time:

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(2) The Company agrees that all representations, warranties, terms and conditions of this Agreement (including the conditions in Section 6) shall be construed as conditions and complied with so far as they relate to acts to be performed or caused to be performed by it, that it will use its reasonable best efforts to cause such representations, warranties, terms and conditions not to be breached and to be complied with, and that any material breach (or in the case of any representation, warranty, term or condition qualified by materiality, any breach) or failure by it to comply with any such conditions shall entitle the Representative on behalf of the Underwriters to terminate their obligations under this Agreement by notice to that effect given to the Company at or prior to the First Closing Date or the Option Closing Date, as the case may be, unless otherwise expressly provided in this Agreement.

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(3) The rights of termination contained in this Section 8 may be exercised by the Underwriters (or any of them) and are in addition to any other rights or remedies that the Underwriters may have in respect of any default, act or failure to act or non-compliance by the Company in respect of any of the matters contemplated by this Agreement or otherwise. In the event of any such termination, there shall be no further liability or obligation on the part of an Underwriter to the Company, or on the part of the Company to the Underwriter except in respect of any liability or obligation under any of Section 5, Section 10 and Section 11 hereof which shall at all times remain in full force and effect and shall survive such termination.

(1) Subject to the terms of this Agreement, the obligation of the Underwriters to purchase the Firm Units or the Additional Units, if applicable, at the First Closing Date or the Option Closing Date, as the case may be, shall be several and not joint and several and shall be limited to the number and equivalent percentage of the Firm Units or the Additional Units, if applicable, set out opposite the name of the Underwriters respectively below (subject to such adjustment as the Representative may determine to eliminate fractional shares):

(2) If, on the First Closing Date or the applicable Option Closing Date, as the case may be, any one or more of the Underwriters shall fail or refuse to purchase the Offered Units that it or they have agreed to purchase hereunder on such date, and the aggregate number of Offered Units which such defaulting Underwriter or Underwriters agreed but failed or refused to purchase does not exceed 10% of the aggregate number of the Offered Units to be purchased on such date, the Representative may make arrangements satisfactory to the Company for the purchase of such Offered Units by other persons, including any of the Underwriters, but if no such arrangements are made by such First Closing Date or the applicable Option Closing Date, as the case may be, the other Underwriters shall be obligated, severally and not jointly, in the proportions that the number of Firm Units set forth opposite their respective names in this Section 9 bears to the aggregate number of Firm Units set forth opposite the names of all such non-defaulting Underwriters, or in such other proportions as may be specified by the Representative with the consent of the non-defaulting Underwriters, to purchase the Offered Units which such defaulting Underwriter or Underwriters agreed but failed or refused to purchase on such date. If, on the First Closing Date or the applicable Option Closing Date, as the case may be, any one or more of the Underwriters shall fail or refuse to purchase the Offered Units and the aggregate number of Offered Units with respect to which such default occurs exceeds 10% of the aggregate number of Offered Units to be purchased on such date, and arrangements satisfactory to the Representative and the Company for the purchase of such Offered Units

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are not made within 48 hours after such default, this Agreement shall terminate without liability of any party to any other party (other than the defaulting underwriter, who shall remain liable to the Company) except that the provisions of Section 5, Section 10 and Section 11 shall at all times be effective and shall survive such termination. In any such case either the Representative or the Company shall have the right to postpone the First Closing Date or the applicable Option Closing Date, as the case may be, but in no event for longer than five days in order that the required changes, if any, to the Registration Statement and the Prospectuses or any other documents or arrangements may be effected.

(3) As used in this Agreement, the term “Underwriter” shall be deemed to include any person substituted for a defaulting Underwriter under this Section 9. Any action taken under this Section 9 shall not relieve any defaulting Underwriter from liability in respect of any default of such Underwriter under this Agreement.

(1) Indemnification Provided by the Company in favour of the Underwriters. The Company (in this Section 10, the “Indemnifying Party”) agrees to indemnify, defend and hold harmless each Underwriter, its affiliates, directors, officers, partners, employees, advisors, shareholders and agents, and any person who controls any Underwriter within the meaning of Section 15 of the Securities Act or Section 20 of the Exchange Act, and the successors and assigns of all of the foregoing persons (collectively, the “Indemnified Parties” and individually, an “Indemnified Party”), from and against any loss, damage, expense, liability, action, suit, proceeding or claim (including the reasonable cost of investigation) (each a “Claim” and, collectively, the “Claims”) which, jointly or severally, any such Underwriter or any such person may incur insofar as such Claim (or actions in respect thereof as contemplated below) arises out of or is based upon (i) any untrue statement or alleged untrue statement of a material fact contained in the Registration Statement, or any amendment thereto, including any information deemed to be a part thereof for purposes of Section 11 under the Securities Act, or the omission or alleged omission therefrom of a material fact required to be stated therein or necessary to make the statements therein not misleading, (ii) any misrepresentation within the meaning of Canadian Securities Laws or untrue statement or alleged untrue statement of a material fact contained in the Time of Sale Prospectus, any free writing prospectus that the Company has used, referred to or filed, or is required to file, pursuant to Rule 433(d) of the Securities Act and the Prospectuses or any Supplementary Material (or any amendment or supplement thereto), or the omission or alleged omission therefrom of a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading, (iii) the breach by the Company of any of its representations, warranties or covenants in this Agreement or the failure of the Company to comply with any of its obligations under this Agreement, (iv) the Company not complying with any requirement of Canadian Securities Laws or the Securities Act and the applicable rules and regulations of the Canadian Commissions, the SEC or applicable TSXV or NASDAQ requirements, or (v) any order made or inquiry, investigation or proceeding (formal or informal) commenced or threatened by any securities regulatory authority or any other competent authority or under the Securities Act, the Exchange Act, the Canadian Securities Laws, other federal, provincial or state statutory law or regulation, or the laws or regulations of foreign jurisdictions in which the Offered Units have been offered or sold,

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based upon the circumstances described in (i), (ii), (iii) or (iv) above which operates to prevent or restrict trading in or distribution of the Offered Units or any other securities of the Company in any of the Qualifying Jurisdictions; and to reimburse each Indemnified Party for any and all expenses (including the fees and disbursements of counsel chosen by the Representative) as such expenses are reasonably incurred by such Indemnified Party in connection with investigating, defending, settling, compromising or paying any such Claim. Notwithstanding the foregoing, the Company shall not be liable in any such case to the extent that any such Claim arises out of or is based upon an untrue statement or alleged untrue statement or omission or alleged omission made in the Registration Statement, the Time of Sale Prospectus, any free writing prospectus, the U.S. Prospectus, the Canadian Prospectus or any Supplementary Material, in reliance upon and in conformity with information provided in writing to the Company by any Underwriter specifically for use therein, being understood and agreed that the only such information furnished by the Lead Underwriters to the Company expressly for use in the Registration Statement, , the Time of Sale Prospectus, any free writing prospectus, the U.S. Prospectus, the Canadian Prospectus or any Supplementary Material are the statements set forth therein under the heading “Plan of Distribution – Price Stabilization and Short Positions.” Furthermore, the Company shall not in any event be liable to the Underwriters for loss of any anticipated profits from the transactions contemplated by this Agreement.

(2) Notification. If any matter or thing contemplated by this Section 10 shall be asserted against any Indemnified Party in respect of which indemnification is or might reasonably be considered to be provided, such Indemnified Party will notify the Indemnifying Party as soon as possible and, in any event on a timely basis, of the nature of such Claim and the Indemnifying Party shall be entitled (but not required) to assume the defence of any suit brought to enforce such Claim; provided, however, that the defence shall be through legal counsel acceptable to the Indemnified Party, acting reasonably. Failure or delay by the Indemnified Party to so notify shall not relieve the Indemnifying Party of its obligation of indemnification hereunder unless (and only to the extent that) such failure or delay results in forfeiture by the Indemnifying Party, of substantive rights or defences.

(3) Settlement. The Indemnifying Party shall not, without the prior written consent of the Underwriters, which shall not be unreasonably withheld, settle or compromise or consent to the entry of any judgment in any pending or threatened Claim in respect of which indemnification may be sought hereunder (whether or not the Indemnified Parties are a party to such Claim), unless such settlement, compromise or consent includes an unconditional release of each of the Indemnified Parties from all liability arising out of such Claim. Notwithstanding the foregoing, the Indemnifying Party shall not be liable for the settlement of any Claim in respect of which indemnity may be sought hereunder effected without its written consent, which consent shall not be unreasonably withheld.

(4) Retaining Counsel. In any such Claim, the Indemnified Party shall have the right to retain a single other counsel (in addition to local counsel) to act on the Indemnified Party’s behalf, provided that the reasonable fees and disbursements of such other counsel shall be paid by the Indemnified Party, unless: (i) the Indemnifying Party and the Indemnified Party mutually agree to retain such other counsel, (ii) the Indemnifying Party has not assumed the defence of the action within a reasonable period of time after receiving notice of the Claim,

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(iii) in the opinion of counsel, there are one or more defences available to the Indemnified Party which are different from or in addition to those available to the Indemnifying Party or (iv) in the opinion of counsel, the named parties to any such Claim (including any third or implicated party) include both the Indemnified Party on the one hand and the Indemnifying Party on the other hand, and the representation of the Company and the Indemnified Party by the same counsel would be inappropriate due to actual or potential conflicting interests, in which event such fees and disbursements shall be paid by the Indemnifying Party to the extent that they have been reasonably incurred.

(5) Expenses. The Indemnifying Party agrees that if any action, suit, proceeding or claim shall be brought against, or an investigation commenced in respect of, the Indemnifying Party and any Underwriter and personnel of any Underwriter shall be required to testify, participate or respond in respect of or in connection with this Agreement, the Underwriters shall have the right to employ their own counsel in connection therewith and the Indemnifying Party will reimburse the Underwriters monthly for reasonable out-of-pocket expenses as may be incurred, including fees and disbursements of the Underwriters’ counsel.

(6) Right of Indemnity in Favour of Others. With respect to any Indemnified Party who is not a party to this Agreement, it is the intention of the Company to constitute the Underwriters as trustee for such Indemnified Party of the rights and benefits of this Section 10 and the Underwriters agree to accept such trust and to hold the rights and benefits of this Section 10 in trust for and on behalf of such Indemnified Party.

(7) Responsibility. Except in respect of statements relating solely to the Underwriters or expressly agreed by the Underwriters in writing, neither the Underwriters nor any of their affiliates or advisers will be responsible to the Company or to any other person responsible for the Applicable Prospectuses for verifying the accuracy or fairness of the information published therein or otherwise published by the Company in connection with the offering and sale of the Offered Units.

(8) Non-Prejudice. The indemnity provisions set forth in this Section 10 and the contribution provisions set forth in Section 11 and the obligations of the Company thereunder shall be in addition to any liability which the Company may otherwise have and shall be binding upon and enure to the benefit of any successors, assigns, heirs and personal representatives of the Company and the Indemnified Parties.

(1) Contribution. If the indemnification provided for in Section 10 hereof is unavailable to or unenforceable by an Indemnified Party or insufficient to hold an Indemnified Party harmless in respect of any Claims (as defined in Section 10(1)), then the Company shall contribute to the amount paid or payable by such Indemnified Party as a result of such Claims (i) in such proportion as is appropriate to reflect the relative benefits received by the Company on the one hand and the Underwriters on the other hand from the offering of the Offered Units, or (ii) if the allocation provided by clause (i) above is not permitted by applicable law, in such proportion as is appropriate to reflect not only the relative benefits referred to in clause (i) above but also the relative fault of the Company on the one hand and

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of the Underwriters on the other in connection with the statements or omissions which resulted in such Claims, as well as any other relevant equitable considerations. The relative benefits received by the Company on the one hand and the Underwriters on the other shall be deemed to be in the same respective proportions as the total proceeds from the offering of the Offered Units (net of Underwriters’ Commission but before deducting expenses) received by the Company, and the total Underwriters’ Commission received by the Underwriters, bear to the gross proceeds of the offering of the Offered Units. The relative fault of the Company on the one hand and of the Underwriters on the other shall be determined by reference to, among other things, whether the untrue statement or alleged untrue statement of a material fact or omission or alleged omission relates to information supplied by the Company or by the Underwriters and the parties’ relative intent, knowledge, access to information and opportunity to correct or prevent such statement, omission or misrepresentation referred to in Section 10. The Underwriters’ obligations to contribute pursuant to this Section 11 are several, and not joint, in proportion to their respective underwriting commitments as set forth opposite their respective names in Section 9 hereof. The Underwriters shall not in any event be liable to contribute, in the aggregate, any amounts in excess of the Underwriters’ Commission or any portion of such commission actually received by such Underwriter in connection with the Offered Units underwritten by it and distributed to the public. The amount paid or payable by an Indemnified Party as a result of the Claims referred to above shall be deemed to include, subject to the limitations set forth in Section 10, any legal or other out-of-pocket expenses reasonably incurred by such Indemnified Party in connection with investigating or defending any such losses, claims, damages, liabilities, costs or expenses, whether or not resulting in any such Claims.

(2) Right of Contribution in Addition to Other Rights. The rights to contribution provided in this Section 11 shall be in addition to and not in derogation of any other right to contribution which an Indemnified Party may have by statute or otherwise at law.

(3) Right of Contribution in Favour of Others. With respect to any Indemnified Party who is not a party to this Agreement, it is the intention of the Company to constitute the Underwriters as trustee for such Indemnified Party of the rights and benefits of this Section 11 and the Underwriters agree to accept such trust and to hold the rights and benefits of this section in trust for and on behalf of such Indemnified Party.

(4) Fraudulent Misrepresentation. No person guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of the Securities Act) shall be entitled to contribution from any person who was not guilty of such fraudulent misrepresentation.

The Company undertakes to notify the Representative immediately if it comes to its knowledge at any time up to the First Closing Date or the expiration or termination of the Over-Allotment Option that any of the representations and warranties of the Company in this Agreement was not true or accurate or was misleading in any material respect when given or made or has ceased to be true or accurate in any material respect or has become misleading by reference to the facts or circumstances from time to time subsisting and of all other information of which it becomes aware which may give rise to an obligation to

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prepare and file Supplementary Material. If, at any time prior to the First Closing Date, the Representative shall receive notification pursuant to this section or it shall otherwise become aware that any of the representations and warranties in this Agreement is or has become or is likely to become untrue, inaccurate or misleading in any material respect, the Representative may (without prejudice to its right to terminate their obligations under this Agreement pursuant to Section 8) require the Company at its own expense to make or cause to be made such announcement as the Underwriters may reasonably determine.

The representations, warranties and covenants (including indemnities) of the Company and the Underwriters contained in this Agreement and in any certificate delivered pursuant to this Agreement or in connection with the purchase and sale of the Offered Units shall survive the delivery of and payment for the Offered Units sold hereunder and shall continue in full force and effect unaffected by any subsequent disposition of the Offered Units by the Underwriters or the termination of the Underwriters’ obligations and shall not be limited or prejudiced by any investigation made by or on behalf of the Underwriters in connection with the preparation of the Prospectuses, any amendments or supplements related thereto or the distribution of the Offered Units.

The Company acknowledges and agrees that (a) the purchase and sale of the Offered Units pursuant to this Agreement, including the determination of the Offering Price of the Offered Units and any related discounts and commissions, is an arm’s-length commercial transaction between the Company, on the one hand, and the Underwriters, on the other hand, (b) in connection with the offering contemplated hereby and the process leading to such transaction each Underwriter is and has been acting solely as a principal and is not the agent or fiduciary of the Company or its shareholders, creditors, employees or any other party, (c) no Underwriter has assumed or will assume an advisory or fiduciary responsibility in favour of the Company with respect to the offering contemplated hereby or the process leading thereto (irrespective of whether such Underwriter has advised or is currently advising the Company on other matters) and no Underwriter has any obligation to the Company with respect to the offering contemplated hereby except the obligations expressly set forth in this Agreement, (d) the Underwriters and their respective affiliates may be engaged in a broad range of transactions that involve interests that differ from those of the Company, and (e) the Underwriters have not provided any legal, accounting, regulatory or tax advice with respect to the offering contemplated hereby and the Company has consulted its own legal, accounting, regulatory and tax advisors to the extent it deemed appropriate.

All communications hereunder shall be in writing and shall be mailed, hand delivered, or telecopied and confirmed to the parties hereto as follows:

Euro Pacific Canada Inc.

130 King Street West

Suite 2820

Toronto, ON M5X 1A9

Facsimile: (647) 436-7688

Attention:  Rob Purse, President

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with a copy to:

Stikeman Elliott LLP

5300 Commerce Court West

199 Bay Street

Toronto, Ontario M5L 1B9

Facsimile: (416) 947-0866

Attention:  Ian G. Putnam

and a copy to:

Morrison & Foerster LLP

1290 Avenue of the Americas

New York, NY 10104

Facsimile: (212) 468-7900

Attention:  Jonathan M.A. Melmed

Acasti Pharma Inc.

545 Promenade du Centropolis, Suite 1000

Laval, Québec H7T0B3

Facsimile: (450) 687-2272

Attention:  Xavier Harland, Chief Financial Officer

with a copy to:

Osler, Hoskin & Harcourt LLP

1000 De La Gauchetière Street West

Suite 2100

Montréal, QC H3B4W5

Facsimile: (514) 904-5366

Attention:  François Paradis

Any party hereto may change the address for receipt of communications by giving written notice to the others. The parties may change their respective addresses and facsimile numbers for notice, by notice given in the manner aforesaid. Any such notification shall be deemed to be effective when telecopied or delivered, if telecopied or delivered to the recipient on a business day and before 3:00 p.m. (local time) on such business day, and otherwise shall be deemed to be given at 9:00 a.m. (local time) on the next following business day.

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The Company shall be entitled to rely and shall act on any notice, waiver, extension or other communication given by or on behalf of the Underwriters by the Representative, which has authority to bind the Underwriters with respect to all matters covered by this Agreement insofar as such matters relate to the Underwriters, with the exception of matters arising under Section 10 and Section 11, or notice of termination pursuant to Section 8, which notice may be given by any of the Underwriters. The Company agrees that all written and oral opinions, advice, analysis and materials provided by the Underwriters in connection with the offering and sale of the Offered Units are intended solely for the Company’s benefit and for the Company’s use only and the Company covenants and agrees that no such opinions, advice or material will be used for any other purpose whatsoever or reproduced, disseminated, quoted from or referred to in whole or in part at any time, in any manner or for any purpose, without the prior consent of the Representative in each specific circumstance.

This Agreement will inure to the benefit of and be binding upon the parties hereto, including any substitute Underwriters pursuant to Section 9 hereof, and to the benefit of the employees, officers and directors and controlling persons referred to in Section 10 and Section 11, and in each case their respective successors and personal representatives, and no other person will have any right or obligation hereunder. The term “successors” shall not include any purchaser of the Offered Units as such from any of the Underwriters merely by reason of such purchase.

Time shall be of the essence of this Agreement.

The invalidity or unenforceability of any Section, paragraph or provision of this Agreement shall not affect the validity or enforceability of any other Section, paragraph or provision hereof. If any Section, paragraph or provision of this Agreement is for any reason determined to be invalid or unenforceable, there shall be deemed to be made such minor changes (and only such minor changes) as are necessary to make it valid and enforceable.

This Agreement shall be governed by and construed in accordance with the internal laws of the state of New York and the federal laws of the United States applicable therein governing contracts made and to be performed wholly therein and without reference to its principles governing the choice or conflict of laws. The parties hereto irrevocably attorn and submit to the exclusive jurisdiction of the federal courts of the United States of America, sitting in the City of New York and the Borough of Manhattan (the “Specified Courts”), with respect to any dispute related to this Agreement. The parties irrevocably and unconditionally waive any objection to the laying of venue of any suit, action, or other proceeding in the Specified Courts and irrevocably and unconditionally waive and agree not to plead or claim in any such court that any such suit, action, or other proceeding brought in any such court has been brought in an inconvenient forum.

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The Company has filed with the SEC a Form F-X appointing CT Corporation System (or any successor) (together with any successor, the “Agent for Service”), as its agent to accept and acknowledge on its behalf service of any and all process which may be served in any action, proceeding or counterclaim in any way relating to or arising out of this Agreement.

This Agreement may be executed by any one or more of the parties to this Agreement in any number of counterparts, each of which shall be deemed to be an original, but all such counterparts shall together constitute one and the same instrument. The transmission by facsimile or e-mail of a copy of the execution page hereof reflecting the execution of this Agreement by any party hereto shall be effective to evidence that party’s intention to be bound by this Agreement and that party’s agreement to the terms, provisions and conditions hereof, all without the necessity of having to produce an original copy of such execution page.

The parties have expressly required this Agreement and all other documents required or permitted to be given or entered into pursuant hereto to be drawn up in the English language only. Les parties ont expressément demandé que la présente convention de prise ferme ainsi que tout autre document à être ou pouvant être donné ou conclu en vertu des dispositions des présentes, soient rédigés en langue anglaise seulement.

(1) This Agreement constitutes the entire agreement of the parties to this Agreement and supersedes all prior written or oral and all contemporaneous oral agreements, understandings and negotiations with respect to the subject matter hereof including the engagement letter dated November 22, 2013 between the Company and the Representative. This Agreement may not be amended or modified unless in writing by all of the parties hereto, and no condition herein (express or implied) may be waived unless waived in writing by each party whom the condition is meant to benefit. The Section headings herein are for the convenience of the parties only and shall not affect the construction or interpretation of this Agreement.

(2) The Company acknowledges that the Underwriters’ research analysts and research departments are required to be independent from their respective investment banking divisions and are subject to certain regulations and internal policies, and that such Underwriters’ research analysts may hold and make statements or investment recommendations and/or publish research reports with respect to the Company and/or the offering that differ from the views of its investment bankers. The Company hereby waives and releases, to the fullest extent permitted by law, any claims that the Company may have against the Underwriters with respect to any conflict of interest that may arise from the fact that the views expressed by their independent research analysts and research departments may be different from or inconsistent with the views or advice communicated to the Company by such Underwriters’ investment banking divisions. The Company

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acknowledges that each of the Underwriters is a full service securities firm and as such from time to time, subject to applicable securities laws, may effect transactions for its own account or the account of its customers and hold long or short position in debt or equity securities of the companies which may be the subject to the transactions contemplated by this Agreement.

[The Remainder of This Page Intentionally Left Blank; Signature Page Follows]

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The foregoing is agreed by the parties as of the date first mentioned above.

[Signature Page to Underwriting Agreement]

[Signature Page to Underwriting Agreement]

[Signature Page to Underwriting Agreement]

SCHEDULE “A”

INFORMATION AND FREE WRITING PROSPECTUSES

INCLUDED IN THE TIME OF SALE PROSPECTUS

Pricing Information:

Number of Firm Units: 16,000,000

Number of Additional Offered Units: 2,400,000

Number of Unit Shares per Unit: One (1) Unit Share

Number of Warrants per Unit: One (1) Warrant

Exercise price of Warrants: US$1.50

Price to Public: US$1.25 per Unit

Underwriters’ Commission: 3.0% of the gross proceeds from the sale of Firm Units to those purchasers agreed to by the Representative and the Company, and 6.0% of the gross proceeds from the sale of Offered Units to all other purchasers

Closing Date: December 3, 2013

EXHIBIT “A”

LIST OF PERSONS AND ENTITIES SUBJECT TO LOCK-UP

Directors

Henri Harland

Ronald Denis

Valier Boivin

Jean-Claude Debard

Harlan W. Waksal

Officers

Tina Sampalis

Xavier Harland

Pierre Lemieux

Others

Neptune Technologies & Bioressources Inc.

EXHIBIT “B”

FORM OF LOCK-UP AGREEMENT

November     , 2013

Euro Pacific Canada Inc.

As Representative of the several Underwriters

c/o Euro Pacific Canada Inc.

130 King Street West, Suite 2820

Toronto, ON M5X 1A9

Ladies and Gentlemen:

The undersigned understands that Euro Pacific Canada Inc. will act as representative (“EuroPac” or the “Representative”) for a group of underwriters (the “Underwriters”) that propose to enter into the Underwriting Agreement (the “Underwriting Agreement”) with Acasti Pharma Inc., a corporation governed by the Business Corporations Act (Quebec) (the “Company”), providing for the purchase by the Underwriters of securities of the Company including the Company’s Class A shares (the “Common Shares”). Capitalized terms used herein and not otherwise defined shall have the meanings set forth in the Underwriting Agreement.

In order to induce the Underwriters to enter in to the Underwriting Agreement, the undersigned hereby agrees that, commencing on the date hereof and continuing until the ninetieth (90th) day following the date of the final prospectus supplement filed by the Company with the Securities and Exchange Commission in connection with such Offering (the “Lock-Up Period”), the undersigned will not, without the prior written consent of EuroPac, on behalf of the Underwriters, directly or indirectly, (1) offer, sell, contract to sell, pledge, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant to purchase, lend, or otherwise transfer or dispose of any Common Shares, or any securities convertible into or exercisable or exchangeable for the Common Shares; (2) enter into any swap or other arrangement that transfers to another, in whole or in part, any of the economic consequences of ownership of the Common Shares, or any securities convertible into or exchangeable for the Common Shares, regardless of whether any such transaction described herein is to be settled by delivery of the Common Shares or such other securities, or by delivery of cash or otherwise; (3) make any demand for, or exercise any right with respect to, the registration or prospectus qualification of any Common Shares or any security convertible into or exercisable of exchangeable for the Common Shares; or (4) publicly announce any intention to do any of the foregoing.

The foregoing restrictions shall not apply to transfers (i) as a bona fide gift or gifts, provided that the donee or donees thereof agree to be bound in writing by the restrictions set forth herein for the remainder of the Lock-Up Period, (ii) by will or intestate succession, (iii) to any trust for the direct or indirect benefit of the undersigned or the immediate family of the undersigned, (iv) to any partner, member or stockholder of the undersigned, (v) the exercise of stock options, existing on the date of the Underwriting Agreement, to purchase Common Shares granted under an equity incentive plan of the Company; provided that any shares of Common Stock obtained by such exercise or exchange shall remain subject to the terms of this Lock-Up Agreement, and (vi) [of Common Shares

to the Company]¹ [of up to an aggregate of 100,000 Common Shares when combined with transfers under this subclause (vi) by all persons who execute an agreement substantially in the form of this Lock-Up Agreement in connection with the Offering,]² to satisfy withholding taxes for any equity award granted prior to the date of the Underwriting Agreement, such as upon exercise, vesting, lapse of substantial risk of forfeiture, or other similar taxable event, provided that in connection with transactions described in clauses (ii), (iii) and (iv) above, the recipient (as applicable) agrees to be bound in writing by the restrictions set forth herein for the remainder of the Lock-Up Period and the related transfer shall not involve a disposition for value. For purposes of this Lock-Up Agreement, “immediate family” shall mean any relationship by blood, marriage or adoption, not more remote than first cousin. [Furthermore, the restrictions set forth in the paragraph directly above shall not apply to the offer, sale, disposition, tender or transfer of Common Shares held by Neptune Technologies & Bioressources Inc. (“Neptune”) (x) as full or partial consideration for assets or common shares in connection with arm’s length acquisitions and (y) upon the exercise of call-options issued prior to the date of the Underwriting Agreement to certain employees, officers and directors of Neptune to purchase such Common Shares; provided that the recipient of such Common Shares agrees to be bound in writing by the restrictions set forth herein for the remainder of the Lock-Up Period.]¹

The undersigned hereby agrees and consents to the entry of stop transfer instructions with the Company’s transfer agent against the transfer of securities of the Company held by the undersigned during the Lock-Up Period (as may have been extended pursuant hereto), except in compliance with this Lock-Up Agreement.

Anything to the contrary notwithstanding, if (i) the Underwriting Agreement does not become effective by November 30, 2013, (ii) after becoming effective, the Underwriting Agreement (other than the provisions thereof which survive termination) shall terminate or be terminated prior to payment for and delivery of the Common Shares to be sold thereunder, or (iii) prior to the Underwriting Agreement becoming effective, the Company notifies the Representative in writing that it does not intend to proceed with the Offering, this Lock-Up Agreement shall lapse and become null and void and the undersigned shall be released from all obligations under this Lock-Up Agreement.

The undersigned hereby represents and warrants that the undersigned has full power and authority to enter into this Lock-Up Agreement. This Lock-Up Agreement may not be revoked by the undersigned or the Company. All authority herein conferred or agreed to be conferred shall survive the death or incapacity of the undersigned and any obligations of the undersigned shall be binding upon the heirs, personal representatives, successors and assigns of the undersigned.

This Lock-Up Agreement shall be governed by and construed in accordance with the laws of the State of New York.