The information in this preliminary prospectus supplement is not complete and may be changed. This preliminary prospectus supplement and the accompanying prospectus are not an offer to sell these securities and are not soliciting an offer to buy these securities in any jurisdiction where the offer or sale is not permitted.

Filed pursuant to Rule 424(b)(5)

Registration No. 333-223464

Subject to Completion, dated OCTOBER 3, 2018

PRELIMINARY PROSPECTUS SUPPLEMENT

(To Prospectus dated March 16, 2018)

                   Common Shares

We are offering           common shares. Our common shares trade on the NASDAQ Stock Market, or NASDAQ, and on the TSX Venture Exchange, or TSXV, under the symbol “ACST.” On October 2, 2018, the closing price of our common shares on NASDAQ was US$1.40 per share and on the TSXV was $1.75 per share.

The aggregate market value of our outstanding common shares held by non-affiliates is approximately US$57.7 million, based on 36,776,070 common shares outstanding as of October 2, 2018 at a per share price of US$1.57, based on the closing sale price of our common shares on NASDAQ on October 1, 2018. In addition, we have not sold any securities pursuant to General Instruction I.B.5 of Form F-3 during the prior 12 calendar month period that ends on and includes the date of this prospectus supplement.

________________________

(1) See “Underwriting” for additional disclosure regarding underwriting discounts, commissions and estimated offering expenses.

Investing in our common shares involves a high degree of risk. Please consider carefully the “Risk Factors” section beginning on page S-12 of this prospectus supplement and page 6 of the accompanying prospectus, as well as the section captioned “Item 3 – Key Information – D. Risk Factors” in our Annual Report on Form 20-F for the fiscal year ended March 31, 2018, which is incorporated by reference into this prospectus supplement and the accompanying prospectus.

We have also granted the underwriters an option for a period of 30 days from the date of this prospectus supplement to purchase up to           common shares at the public offering price per common share, less the underwriting discounts and commissions, to cover over-allotments, if any. If the underwriters exercise their option in full, the total underwriting discounts and commissions payable by us will be $                , and the total proceeds to us, before expenses, will be $               .

On October 3, 2018, we commenced a separate and concurrent public offering in Canada of common shares under a Canadian prospectus filed with certain Canadian securities regulatory authorities in reliance on Regulation S under the Securities Act of 1933, as amended. The number of common shares to be offered and sold in Canada and other terms of the offering in Canada will be determined at the time of pricing of that offering.

We are an “emerging growth company” under the U.S. Jumpstart Our Business Startups Act of 2012, and as such, may elect to comply with certain reduced public company reporting requirements.

Neither the U.S. Securities and Exchange Commission, or SEC, nor any U.S. state securities commission or any Canadian securities regulator has approved or disapproved of these securities or determined if this prospectus supplement and the accompanying prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The common shares offered by this prospectus supplement and accompanying prospectus have not been and will not be qualified for sale under the securities laws of any province or territory of Canada. This prospectus supplement and accompanying prospectus have not been filed in respect of, and will not qualify, any distribution of shares in any province or territory of Canada.

The underwriters expect to deliver the common shares against payment on or about                , 2018, subject to customary closing conditions.

Sole Book-Running Manager

Oppenheimer & Co.

Co-Manager

Aegis Capital Corp.

The date of this prospectus supplement is                    , 2018.

TABLE OF CONTENTS

PROSPECTUS SUPPLEMENT

PROSPECTUS

ABOUT THIS PROSPECTUS SUPPLEMENT

This document is part of a “shelf” registration statement on Form F-3 that we filed with the SEC, and is in two parts. The first part is this prospectus supplement, which describes the specific terms of this offering of common shares and also adds to and updates information contained in the accompanying prospectus and the documents incorporated by reference into this prospectus supplement and the accompanying prospectus. The second part, the accompanying prospectus dated March 16, 2018, including the documents incorporated by reference into it, provides more general information. Generally, when we refer to this “prospectus,” we are referring to both parts of this document combined.

If there is any inconsistency between the information in this prospectus supplement and the accompanying prospectus, you should rely on the information in this prospectus supplement; provided that if any statement in one of these documents is inconsistent with a statement in another document having a later date and that is incorporated by reference herein, the statement in the document having the later date modifies or supersedes the earlier statement.

We further note that the representations, warranties and covenants made by us in any agreement that is filed as an exhibit to any document that is incorporated by reference into this prospectus supplement or the accompanying prospectus were made solely for the benefit of the parties to such agreement, including, in some cases, for the purpose of allocating risk among the parties to such agreement, and should not be deemed to be a representation, warranty or covenant to you. Moreover, such representations, warranties or covenants were accurate only as of the date when made. Accordingly, such representations, warranties and covenants should not be relied on as accurately representing the current state of our affairs.

Before investing in our securities, please carefully read both this prospectus supplement and the accompanying prospectus together with the documents incorporated by reference herein and therein, as listed under “Documents Incorporated by Reference,” and the additional information described below under “Where You Can Find More Information.”

You should rely only on the information contained in or incorporated by reference into this prospectus. We have not authorized anyone to provide you with different information. If anyone provides you with different or inconsistent information, you should not rely on it. The distribution or possession of this prospectus in or from certain jurisdictions may be restricted by law. This prospectus is not an offer to sell the securities and is not soliciting an offer to buy the securities in any jurisdiction where the offer or sale is not permitted or where the person making the offer or sale is not qualified to do so or to any person to whom it is not permitted to make such offer or sale. You should assume that the information contained in this prospectus is accurate only as of the date on the front cover of this prospectus supplement, or accompanying prospectus, as applicable, and the information incorporated by reference into this prospectus is accurate only as of the date of the document incorporated by reference. Our business, financial condition, results of operations and prospects may have changed since that date.

Other than in the United States, no action has been taken by us or the underwriters that would permit a public offering of the securities offered by this prospectus supplement in any jurisdiction where action for that purpose is required. The common shares offered by this prospectus supplement may not be offered or sold, directly or indirectly, nor may this prospectus supplement or any other offering material or advertisements in connection with the offer and sale of any such securities be distributed or published in any jurisdiction, except under circumstances that will result in compliance with the applicable rules and regulations of that jurisdiction. Persons into whose possession this prospectus supplement comes are advised to inform themselves about and to observe any restrictions relating to the offering and the distribution of this prospectus supplement. This prospectus supplement does not constitute an offer to sell or a solicitation of an offer to buy any securities offered by this prospectus supplement in any jurisdiction in which such an offer or a solicitation is unlawful.

Owning common shares may subject you to tax consequences in the United States. This prospectus supplement or the accompanying prospectus may not describe these tax consequences fully. You should read the tax discussion in this prospectus supplement and consult your own tax advisor with respect to your own particular circumstances.

We own or have rights to trademarks, service marks or trade names that we use in connection with the operation of our business. In addition, our name, logo and website names and addresses are our service marks or trademarks. CaPre® is our registered trademark. The other trademarks, trade names and service marks appearing in this prospectus and the documents incorporated by reference into this prospectus supplement are the property of their respective owners. Solely for convenience, the trademarks, service marks, tradenames and copyrights referred to in this prospectus supplement are listed without the ©, ® and TM symbols, but we will assert, to the fullest extent under applicable law, our rights or the rights of the applicable licensors to these trademarks, service marks and tradenames.

Unless stated otherwise or the context otherwise requires, references in this prospectus supplement and the accompanying prospectus to “Acasti,” the “Company,” “we,” “us,” or “our” refer to Acasti Pharma Inc.

Unless stated otherwise or if the context otherwise requires, all references to dollar amounts in this prospectus supplement are references to Canadian dollars. References to “US$” are to U.S. dollars and references to “CDN$” and “$” are to Canadian dollars. In this prospectus supplement, where applicable, and unless otherwise indicated, amounts are converted from Canadian dollars to U.S. dollars and vice versa by applying the daily average closing rate of exchange for conversion of one Canadian dollar to U.S. dollars as reported by the Bank of Canada on October 2, 2018, which was $1.00 = US$0.7802.

The consolidated financial statements incorporated by reference into this prospectus supplement are presented in accordance with International Financial Reporting Standards as issued by the International Accounting Standards Board.

CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS

This prospectus supplement and the accompanying prospectus, including the documents incorporated by reference herein and therein, contain information that may be forward-looking statements within the meaning of U.S. federal securities laws. Forward-looking statements can be identified by the use of terms such as “may,” “will,” “should,” “expect,” “plan,” “anticipate,” “believe,” “intend,” “estimate,” “predict,” “potential,” “continue” or other similar expressions concerning matters that are not statements about the present or historical facts. Forward-looking statements in this prospectus supplement, the accompanying prospectus and in the documents incorporated by reference herein and therein include, among other things, information or statements about:

In addition, the forward-looking statements in this prospectus supplement, the accompanying prospectus and in the documents incorporated by reference herein and therein are subject to a number of known and unknown risks, uncertainties and other factors, including those described in this prospectus supplement under the heading “Risk Factors,” many of which are beyond our control, that could cause our actual results and developments to differ materially from those that are disclosed in or implied by the forward-looking information, including, among others:

All of the forward-looking statements in this prospectus supplement, the accompanying prospectus and the documents incorporated by reference herein and therein are qualified by this cautionary statement. There can be no guarantee that the results or developments that we anticipate will be realized or, even if substantially realized, that they will have the consequences or effects on our business, financial condition or results of operations that we anticipate. As a result, you should not place undue reliance on the forward-looking statements. Except as required by applicable law, we do not undertake to update or amend any forward-looking statements, whether as a result of new information, future events or otherwise. All forward-looking statements in this prospectus supplement, are made as of the date of this prospectus supplement. Forward-looking statements made in the accompanying prospectus and the documents incorporated by reference therein are made as of the date of the original document and have not been updated by us, except as expressly provided for in this prospectus supplement.

EXCHANGE RATES

The following table presents the high, low, average and period end exchange rate for one Canadian dollar expressed as one U.S. dollar for each of our last five fiscal years. The average rate is calculated using the average of the exchange rates on the last day of each month during the period.

The following table presents the high, low, average and period end exchange rate for one Canadian dollar expressed as one U.S. dollar for each month during the previous six months.

The exchange rates above are based upon the noon buying rate, as quoted by the Bank of Canada. As of May 1, 2017, the Bank of Canada no longer publishes updated data for exchange rates published under previous methodologies, including daily noon and closing rates as well as high and low exchange rates. For the month of May 2017 and each month thereafter, the exchange rate presented above is based upon the daily average closing rate. As of October 2, 2018, the exchange rate for one Canadian dollar expressed as one U.S. dollar, as quoted by the Bank of Canada was $1.00 = US$0.7802.

PROSPECTUS SUPPLEMENT SUMMARY

This summary highlights certain information about us, this offering and selected information contained elsewhere in or incorporated by reference into this prospectus supplement and the accompanying prospectus. This summary is not complete and does not contain all of the information that you should consider before deciding whether to invest in our common shares. For a more complete understanding of our company and this offering, we encourage you to read and consider carefully the more detailed information in this prospectus supplement and the accompanying prospectus, including the information referred to under the heading “Risk Factors” in this prospectus supplement beginning on page S-12 and in the sections captioned “Item 3 – Key Information – Risk Factors” in our Annual Report on Form 20-F for the fiscal year ended March 31, 2018, which is incorporated by reference into this prospectus supplement and the accompanying prospectus, the other information incorporated by reference into this prospectus supplement and the accompanying prospectus, and the information included in any free writing prospectus that we have authorized for use in connection with this offering.

Our Company

We are a biopharmaceutical innovator focused on the research, development and commercialization of prescription drugs using OM3 fatty acids derived from krill oil. OM3 fatty acids have extensive clinical evidence of safety and efficacy in lowering TGs in patients with HTG. Our lead product candidate is CaPre, an OM3 phospholipid therapeutic, which we are developing initially for the treatment of severe HTG, a condition characterized by very high or severe levels of TGs in the bloodstream (³ 500 mg/dL).

In accordance with a study published in 2009 in the Archives of Internal Medicine by Ford et al., it is estimated that three to four million people in the United States have severe HTG. In primary qualitative market research studies with Key Opinion Leaders, High Volume Prescribers and Pharmacy Benefit Managers commissioned by Acasti in August 2016 and November of 2017 by DP Analytics, a division of Destum Partners, physicians interviewed indicated a significant unmet medical need exists for an effective, safe and well-absorbing OM3 therapeutic that can also demonstrate a positive impact on the major blood lipids associated with cardiovascular disease risk. We believe that CaPre will address this unmet medical need if our Phase 3 results reproduce what we observed in our Phase 2 data. We initiated TRILOGY, our Phase 3 clinical program in North America during the second half of 2017 and started clinical site activation as planned at the end of 2017. As of the date of this prospectus supplement, patient enrollment and randomization are continuing on schedule for both studies. We also believe that potential exists to expand CaPre’s initial indication to the roughly 36 million patients with high TGs (blood levels between 200 – 499 mg/dL), although at least one additional clinical trial would likely be required to support FDA approval of a supplemental New Drug Application to expand CaPre’s indications to this segment. Data from our Phase 2 studies indicated that CaPre may also have a positive effect in diabetes and inflammatory diseases, consequently we may also seek to identify new potential indications for CaPre that may be appropriate for future studies and pipeline expansion. In addition, we may also seek to in-license other cardiometabolic drug candidates for drug development and commercialization.

In four clinical trials conducted to date, we saw the following consistent results with CaPre, and we are seeking to demonstrate similar safety and efficacy in our TRILOGY Phase 3 program:

We believe that if we are able to reproduce these results in our TRILOGY Phase 3 program, we potentially could set CaPre apart from current FDA-approved OM3 treatment options, and it could give us a significant clinical and marketing advantage.

Recent Developments

Intellectual Property

On July 24, 2018, we received a Notice of Allowance from the U.S. Patent and Trademark Office (USPTO) on our composition-of-matter patent application for “Concentrated Therapeutic Phospholipid Compositions.” This patent provides comprehensive coverage over a broad range of concentrated phospholipid compositions.

Clinical Update for Our TRILOGY Phase 3 Program

As of August 10, 2018, 126 clinical sites have been activated, 770 patients have been enrolled and 110 patients have been randomized for our TRILOGY Phase 3 program. This is a double-blind, placebo-controlled, 26-week, two-study Phase 3 clinical program that is being conducted in a total of about 500 patients, and it is designed to evaluate the safety and efficacy of CaPre in patients with severe HTG. Additional cGMP production lots of active pharmaceutical ingredient and CaPre were manufactured during the first quarter of 2018, enabling us to continue to accumulate the CaPre inventory required to complete the TRILOGY trials.

As of the date of this prospectus supplement, our TRILOGY Phase 3 program remains on track and we expect to complete patient enrollment by the end of 2018. Our TRILOGY Phase 3 program has already exceed 75% enrollment and 30% randomization at our clinical sites across the U.S., Canada and Mexico.

Canadian Offering

On October 3, 2018, we commenced a separate and concurrent public offering in Canada of common shares under a Canadian prospectus filed with certain Canadian securities regulatory authorities in reliance on Regulation S under the Securities Act of 1933, as amended. The number of common shares to be offered and sold in Canada and other terms of the offering in Canada will be determined at the time of pricing of that offering. There can be no assurance that the offering in Canada will be completed. The offering of common shares pursuant to this prospectus supplement is not contingent upon the completion of the offering of common shares in Canada.

Corporate Information

We were incorporated on February 1, 2002 under Part 1A of the Companies Act (Québec) under the name “9113-0310 Québec Inc”. On August 7, 2008, pursuant to a Certificate of Amendment, we changed our name to “Acasti Pharma Inc.” and on February 14, 2011, the Business Corporations Act (Québec) came into effect and replaced the Companies Act (Québec). We are now governed by the Business Corporations Act (Québec).

Our principal executive offices are currently located at 545 Promenade du Centropolis, Suite 100, Laval, Québec, Canada H7T 0A3. Our telephone number is (450) 686-4555.

The number of common shares to be outstanding immediately after the completion of the offering is based on 36,628,063 common shares outstanding on June 30, 2018, does not give effect to our separate and concurrent public offering of common shares in Canada and excludes the following:

Subsequent to June 30, 2018 and through the date of this prospectus supplement:

Additionally, except as otherwise indicated herein, all information in this prospectus supplement assumes no exercise of the underwriters’ option to purchase additional common shares and does not give effect to our separate and concurrent public offering of common shares in Canada.

RISK FACTORS

Investing in our common shares involves risk. Before making any investment decision, you should carefully read the risk factors set forth below, under the caption “Risk Factors” in the accompanying prospectus and under the caption “Item 3 – Key Information – D. Risk Factors” in our Annual Report on Form 20-F for the fiscal year ended March 31, 2018, and other documents that are incorporated by reference into this prospectus supplement and the accompanying prospectus. It is not possible to predict or identify all such risks. Consequently, we could also be affected by additional factors that are not presently known to us or that we currently consider to be immaterial to us.

The risks we have identified and the risks that remain unknown could materially affect our business, results of operation or financial condition and affect the value of our common shares. You could lose all or part of your investment.

You will experience immediate dilution in the book value per share of the common shares you purchase.

Because the price per share of our common shares being offered is substantially higher than the book value per share of our common shares, you will suffer substantial dilution in the net tangible book value of the common shares you purchase in this offering. Based on the public offering price of US$          per share and the net tangible book value of the common shares of $0.15 per share as of June 30, 2018, if you purchase common shares in this offering, you will suffer dilution of $         per share in the net tangible book value of the common shares. The foregoing does not give effect to our separate and concurrent public offering of common shares in Canada.

The market price of our common shares may be affected by low volume.

Our common shares have a relatively low average daily volume. The average daily trading volume during the 90 days prior to October 1, 2018 was approximately 664,105 shares on NASDAQ and approximately 166,760 shares on the TSXV. Without a significantly larger average trading volume, our common shares will be less liquid than the common shares of companies with higher trading volume.  As a result, the trading prices for our common shares may be more volatile.

 There is a significant risk that we may be classified as a PFIC for U.S. federal income tax purposes.

Potential investors in our common shares who are U.S. holders should be aware that, based on our most recent financial statements and projections and given uncertainty regarding the composition of our future income and assets, there is a significant risk that we may be classified as a “passive foreign investment company” or “PFIC” for our current taxable year and possibly subsequent years. If we are a PFIC for any year during a U.S. holder’s holding period of the common shares acquired pursuant to this prospectus, then such U.S. taxpayer generally will be required to treat any gain realized upon a disposition of such common shares or any so-called “excess distribution” received on such common shares, as ordinary income (with a portion subject to tax at the highest rate in effect), and to pay an interest charge on a portion of such gain or excess distribution. In certain circumstances, the sum of the tax and the interest charge may exceed the total amount of proceeds realized on the disposition, or the amount of excess distribution received, by the U.S. holder. Subject to certain limitations, a timely and effective QEF Election under Section 1295 of the Code or a Mark-to-Market election under Section 1296 of the Code may be made with respect to the common shares. A U.S. holder who makes a timely and effective QEF Election generally must report on a current basis its share of our net capital gain and ordinary earnings for any year in which we are a PFIC, whether or not we distribute any amounts to our shareholders. A U.S. holder who makes the Mark-to-Market Election generally must include as ordinary income each year the excess of the fair market value of their common shares over the holder’s basis therein. This paragraph is qualified in its entirety by the discussion below under the heading “Certain U.S. Federal Income Tax Considerations—U.S. Federal Income Tax Considerations of the Acquisition, Ownership, and Disposition of Common Shares—Passive Foreign Investment Company Rules”. Each potential investor who is a U.S. holder should consult its own tax advisor regarding the U.S. federal, U.S. state and local, and non-U.S. tax consequences of the acquisition, ownership, and disposition of common shares acquired pursuant to this prospectus, the U.S. federal tax consequences of the PFIC rules, and the availability of any election that may be available to the holder to mitigate adverse U.S. federal income tax consequences of holding shares in a PFIC.

We have broad discretion to determine how to use the proceeds raised in this offering, and we may not use the proceeds effectively.

We intend to use the net proceeds from this offering to fund our TRILOGY Phase 3 program, to advance partnering discussions around the world and for working capital and general corporate purposes. Our management will have broad discretion over the use of proceeds from this offering, and we could spend the proceeds from this offering in ways with which you may not agree or that do not yield a favorable return. Accordingly, you will be relying on the judgment of our management with regard to the use of these net proceeds, and you will not have the opportunity as part of your investment decision to assess whether the proceeds are being used appropriately. Our needs may change as the business and the industry that we address evolves. It is possible that the proceeds will be invested in a way that does not yield a favorable, or any, return. The failure of our management to use such funds effectively could have a material adverse effect on our business, financial condition, operating results and cash flow.

Sales of a substantial number of our common shares, or the perception that such sales might occur, could adversely affect the trading price of our common shares.

As of October 2, 2018, we had 36,776,070 common shares outstanding. If this offering is completed, the number of common shares that we have outstanding will increase. Sales of a substantial number of our common shares, or the perception that such sales might occur, could adversely affect the trading price of our common shares. We cannot predict the effect, if any, that market sales of those common shares or the availability of those common shares for sale will have on the market price of our common shares.

USE OF PROCEEDS

We estimate that the net proceeds to us from this offering will be approximately US$           million, after deducting the underwriter discounts, commissions and estimated offering expenses payable by us, as described in “Underwriting.” If the underwriters exercise in full their option to purchase additional common shares, we estimate that we will receive net proceeds of approximately US$           million, after deducting the underwriter discounts, commissions and estimated offering expenses payable by us.

We intend to use the net proceeds from this offering to fund our TRILOGY Phase 3 program, to advance partnering discussions around the world and for working capital and general corporate purposes.

We have not determined the amounts we plan to spend on any of the areas listed above or the timing of these expenditures. Our management will have significant discretion and flexibility in applying the net proceeds from the sale of these securities. Pending our use of the net proceeds from this offering, we may invest the net proceeds in short- and intermediate-term, interest-bearing obligations, investment-grade instruments, certificates of deposit or government securities, or hold them as cash.

CAPITALIZATION

The following table sets forth our capitalization as of June 30, 2018:

Our capitalization on an as-adjusted basis set forth in the table below does not give effect to our separate and concurrent public offering of common shares in Canada.

This table should be read together with our financial statements and accompanying notes and the other financial information and other documents incorporated by reference into this prospectus supplement and the accompanying prospectus.

The number of common shares outstanding as of June 30, 2018 on an adjusted basis is         common shares. The number of common shares to be outstanding immediately after the completion of the offering is based on 36,628,063 common shares outstanding on June 30, 2018, does not give effect to our separate and concurrent public offering of common shares in Canada and excludes the following:

Subsequent to June 30, 2018 and through the date of this prospectus supplement:

DILUTION

If you invest in our common shares, your interest will be diluted immediately to the extent of the difference between the public offering price per common share and the adjusted net tangible book value per common share after this offering.

The net tangible book value of our common shares as of June 30, 2018 was approximately $5.5 million, or approximately $0.15 per common share. Net tangible book value per common share represents the amount of our total assets, excluding intangible assets, less total liabilities, excluding derivative warrant liabilities, divided by the total number of our common shares outstanding. Dilution per common share to new investors represents the difference between the amount per share paid by purchasers for each common share in this offering and the net tangible book value per common share immediately following the completion of this offering.

After giving effect to the sale of our common shares in the aggregate amount of US$               at an the public offering price of US$               per common share, and after deducting the underwriting discounts, commissions and estimated offering expenses payable by us, our as-adjusted net tangible book value as of June 30, 2018 would have been approximately $               million, or approximately $                per common share. This represents an immediate increase in net tangible book value of approximately $ per common share to our existing shareholders and an immediate dilution in as-adjusted net tangible book value of approximately $                per common share to purchasers of our common shares in this offering, as illustrated by the following table:

If the underwriters exercise their option to purchase additional common shares in full in this offering, the as-adjusted net tangible book value after this offering would be $                per share, the increase in net tangible book value per share to existing shareholders would be $                and the dilution in net tangible book value per share to new investors in this offering would be $                per share, in each case based on the public offering price of US$                per common share.

For purposes of the foregoing discussion, the public offering price of US$                per share has been converted into Canadian dollars based on the daily average exchange rate for one U.S. dollar expressed as one Canadian dollar, as quoted by the Bank of Canada of US$1.00 = $                , as of                , 2018.

The foregoing discussion and table do not give effect to our separate and concurrent public offering of common shares in Canada and also exclude the following:

Subsequent to June 30, 2018 and through the date of this prospectus supplement:

To the extent that any options or warrants are exercised, new options are issued under our equity incentive plans or we otherwise issue additional common shares in the future, there will be further dilution to new investors.

OFFER AND LISTING

Our common shares are listed on the TSXV and the NASDAQ Capital Market under the ticker symbol “ACST”. The following tables set forth, for the periods indicated, the high and low market prices of our common shares as reported on the TSXV and the NASDAQ Capital Market. 

The holders of common shares are entitled to vote at all meetings of our shareholders except meetings at which only holders of a specified class or series of shares are entitled to vote. The holders of common shares are entitled to receive dividends if, as and when declared by the board of directors.

No common shares have been issued subject to call or assessment. There are no pre-emptive or conversion rights and no provisions for redemption or purchase for cancellation, surrender, or sinking or purchase funds. Our common shares must be issued as fully-paid and non-assessable, and are not subject to further capital calls by us. All of the common shares rank equally as to voting rights, participation in a distribution of our assets on a liquidation, dissolution or winding-up, and the entitlement to dividends. Common shares are transferable at the offices of our transfer agent and registrar, Computershare Trust Company of Canada, in Toronto, Ontario, Canada and Montreal, Québec, Canada. There are no restrictions in our corporate documents on the free transferability of the common shares.

UNDERWRITING

We entered into an underwriting agreement with the underwriters named below on                  , 2018. Oppenheimer & Co. Inc. is acting as the representative of the underwriters. The underwriting agreement does not govern any securities sold by us in connection with the separate and concurrent public offering in Canada of common shares under a Canadian prospectus. The underwriting agreement provides for the purchase of a specific number of common shares by each of the underwriters. The underwriters’ obligations are several, which means that each underwriter is required to purchase a specified number of common shares, but is not responsible for the commitment of any other underwriter to purchase common shares. Subject to the terms and conditions of the underwriting agreement, each underwriter has severally agreed to purchase the number of common shares set forth opposite its name below:

The underwriters have agreed to purchase all of the common shares offered by this prospectus supplement (other than those covered by the option to purchase additional common shares described below), if any are purchased.

The common shares offered hereby are expected to be ready for delivery on or about                  , 2018 against payment in immediately available funds.

The underwriters are offering the common shares subject to various conditions and may reject all or part of any order. The representative of the underwriters has advised us that the underwriters propose initially to offer the common shares to the public at the public offering price set forth on the cover page of this prospectus supplement and to dealers at a price less a concession not in excess of US$                  per common share to brokers and dealers. After the common shares are released for sale to the public, the representative may change the offering price, the concession, and other selling terms at various times.

We have granted the underwriters an option to purchase additional common shares. This option, which is exercisable for up to 30 days after the date of this prospectus supplement, permits the underwriters to purchase a maximum of                  additional common shares from us to cover over-allotments, if any. If the underwriters exercise all or part of this option, they will purchase common shares covered by the option at the public offering price that appears on the cover page of this prospectus supplement, less the underwriting discounts and commissions. The underwriters have severally agreed that, to the extent the option to purchase additional common shares is exercised, they will each purchase a number of additional common shares proportionate to the underwriter’s initial amount reflected in the foregoing table.

The following table provides information regarding the amount of the discounts and commissions to be paid to the underwriters by us, before expenses: 

__________________

(1) We have agreed to pay the underwriters a commission of 7% of the aggregate purchase price for common shares sold in the offering.

We estimate that our total expenses of the offering, excluding the estimated underwriting discounts and commissions, will be approximately US$                   , which includes the fees and expenses for which we have agreed to reimburse the underwriters, including fees and expenses of their counsel, up to a maximum aggregate amount of US$125,000.

We have agreed to indemnify the underwriters against certain liabilities, including liabilities under the Securities Act of 1933, as amended.

We and our officers and directors have agreed to a 90-day “lock-up” with respect to our common shares and other of our securities that they beneficially own, including securities that are convertible into common shares and securities that are exchangeable for or exercisable into common shares. This means that, subject to certain exceptions, for a period of 90 days following the date of this prospectus supplement, we and such persons may not offer, sell, pledge or otherwise dispose of these securities without the prior written consent of Oppenheimer & Co. Inc.

Rules of the SEC may limit the ability of the underwriters to bid for or purchase common shares before the distribution of the common shares is completed. However, the underwriters may engage in the following activities in accordance with the rules:

Similar to other purchase transactions, the underwriters’ purchases to cover the syndicate short sales or to stabilize the market price of our common shares may have the effect of raising or maintaining the market price of our common shares or preventing or mitigating a decline in the market price of our common shares. As a result, the price of our common shares may be higher than the price that might otherwise exist in the open market. The imposition of a penalty bid might also have an effect on the price of the common shares if it discourages resales of the common shares.

Neither we nor the underwriters make any representation or prediction as to the effect that the transactions described above may have on the price of the common shares. These transactions may occur on NASDAQ or otherwise. If such transactions are commenced, they may be discontinued without notice at any time.

Electronic Delivery of Preliminary Prospectus

A prospectus supplement in electronic format may be delivered to potential investors by one or more of the underwriters participating in this offering. The prospectus supplement in electronic format will be identical to the paper version of such prospectus supplement. Other than the prospectus supplement in electronic format, the information on any underwriter’s website and any information contained in any other website maintained by an underwriter is not part of this prospectus supplement, the accompanying prospectus or the registration statement of which this prospectus supplement and the accompanying prospectus form a part.

Notice to Non-U.S. Investors

Belgium

The offering is exclusively conducted under applicable private placement exemptions and therefore it has not been and will not be notified to, and this document or any other offering material relating to the common stock has not been and will not be approved by, the Belgian Banking, Finance and Insurance Commission (“Commission bancaire, financière et des assurances/Commissie voor het Bank, Financie en Assurantiewezen”). Any representation to the contrary is unlawful.

Each underwriter has undertaken not to offer sell, resell, transfer or deliver directly or indirectly, any common stock, or to take any steps relating/ancillary thereto, and not to distribute or publish this document or any other material relating to the common stock or to the offering in a manner which would be construed as: (a) a public offering under the Belgian Royal Decree of 7 July 1999 on the public character of financial transactions; or (b) an offering of securities to the public under Directive 2003/71/EC which triggers an obligation to publish a prospectus in Belgium. Any action contrary to these restrictions will cause the recipient and the company to be in violation of the Belgian securities laws.

Canada

The common shares offered by this prospectus supplement and accompanying prospectus have not been and will not be qualified for sale under the securities laws of any province or territory of Canada. This prospectus supplement and accompanying prospectus have not been filed in respect of, and will not qualify, any distribution of shares in any province or territory of Canada. No securities commission or similar regulatory authority in Canada has reviewed or in any way passed upon this document or the merit of the common shares and any representation to the contrary is an offence.

Any offer and sale of the common shares in Canada will be made on a private placement basis only and will be exempt from the requirement to prepare and file a prospectus under applicable Canadian securities laws. Any resale of the common shares acquired by a Canadian investor in this offering must be made in accordance with applicable Canadian securities laws, which may vary depending on the relevant jurisdiction, and which may require resales to be made in accordance with Canadian prospectus requirements, a statutory exemption from the prospectus requirements, in a transaction exempt from the prospectus requirements or otherwise under a discretionary exemption from the prospectus requirements granted by the applicable local Canadian securities regulatory authority. These resale restrictions may under certain circumstances apply to resales of the securities outside of Canada.

France

Neither this prospectus nor any other offering material relating to the common stock has been submitted to the clearance procedures of the Autorité des marchés financiers in France. The common stock has not been offered or sold and will not be offered or sold, directly or indirectly, to the public in France. Neither this prospectus nor any other offering material relating to the common stock has been or will be: (a) released, issued, distributed or caused to be released, issued or distributed to the public in France; or (b) used in connection with any offer for subscription or sale of the common stock to the public in France. Such offers, sales and distributions will be made in France only: (i) to qualified investors (investisseurs qualifiés) and/or to a restricted circle of investors (cercle restreint d’investisseurs), in each case investing for their own account, all as defined in and in accordance with Articles L.411-2, D.411-1, D.411-2, D.734-1, D.744-1, D.754-1 and D.764-1 of the French Code monétaire et financier; (ii) to investment services providers authorised to engage in portfolio management on behalf of third parties; or (iii) in a transaction that, in accordance with article L.411-2-II-1°-or-2°-or 3° of the French Code monétaire et financier and article 211-2 of the General Regulations (Règlement Général) of the Autorité des marchés financiers, does not constitute a public offer (appel public à l’épargne). Such common stock may be resold only in compliance with Articles L.411-1, L.411-2, L.412-1 and L.621-8 through L.621-8-3 of the French Code monétaire et financier.

Israel

This prospectus does not constitute a prospectus under the Israeli Securities Law, 5728-1968 (the “Securities Law”), and has not been filed with or approved by the Israel Securities Authority. In the State of Israel, this document is being distributed only to, and is directed only at, and any offer of the common stock is directed only at, investors listed in the first addendum to the Israeli Securities Law (the “Addendum”), consisting primarily of joint investment in trust funds, provident funds, insurance companies, banks, portfolio managers, investment advisors, members of the Tel Aviv Stock Exchange, underwriters, venture capital funds, entities with equity in excess of NIS 50 million and “qualified individuals”, each as defined in the Addendum (as it may be amended from time to time), collectively referred to as qualified investors (in each case purchasing for their own account or, where permitted under the Addendum, for the accounts of their clients who are investors listed in the Addendum). Qualified investors will be required to submit written confirmation that they fall within the scope of the Addendum, are aware of the meaning of same and agree to it.

Italy

The offering of common stock offered hereby in Italy has not been registered with the Commissione Nazionale per la Società e la Borsa (“CONSOB”) pursuant to Italian securities legislation and, accordingly, the

commmon stock offered hereby cannot be offered, sold or delivered in the Republic of Italy (“Italy”) nor may any copy of this prospectus or any other document relating to the common stock offered hereby be distributed in Italy other than to professional investors (operatori qualificati) as defined in Article 31, second paragraph, of CONSOB Regulation No. 11522 of 1 July, 1998 as subsequently amended. Any offer, sale or delivery of the common stock offered hereby or distribution of copies of this prospectus or any other document relating to the common stock offered hereby in Italy must be made:

Sweden

This prospectus has not been nor will it be registered with or approved by Finansinspektionen (the Swedish Financial Supervisory Authority). Accordingly, this prospectus may not be made available, nor may the common stock offered hereunder be marketed and offered for sale in Sweden, other than under circumstances which are deemed not to require a prospectus under the Financial Instruments Trading Act (1991: 980).

Switzerland

The common stock offered pursuant to this prospectus will not be offered, directly or indirectly, to the public in Switzerland and this prospectus does not constitute a public offering prospectus as that term is understood pursuant to art. 652a or art. 1156 of the Swiss Federal Code of Obligations. The company has not applied for a listing of the common stock being offered pursuant to this prospectus on the SWX Swiss Exchange or on any other regulated securities market, and consequently, the information presented in this prospectus does not necessarily comply with the information standards set out in the relevant listing rules. The common stock being offered pursuant to this prospectus have not been registered with the Swiss Federal Banking Commission as foreign investment funds, and the investor protection afforded to acquirers of investment fund certificates does not extend to acquirers of common stock.

Investors are advised to contact their legal, financial or tax advisers to obtain an independent assessment of the financial and tax consequences of an investment in common stock.

United Kingdom/Germany/Norway/The Netherlands

In relation to each Member State of the European Economic Area which has implemented the Prospectus Directive (each, a “Relevant Member State”) an offer to the public of any common stock which are the subject of the offering contemplated by this prospectus may not be made in that Relevant Member State other than the offers contemplated in this prospectus in name(s) of Member State(s) where prospectus will be approved or passported for the purposes of a non-exempt offer once this prospectus has been approved by the competent authority in such Member State and published and passported in accordance with the Prospectus Directive as implemented in name(s) of relevant Member State(s) except that an offer to the public in that Relevant Member State of any common stock may be made at any time under the following exemptions under the Prospectus Directive, if they have been implemented in that Relevant Member State:

For the purposes of this provision, the expression an “offer to the public” in relation to any common stock in any Relevant Member State means the communication in any form and by any means of sufficient information on the terms of the offer and any common stock to be offered so as to enable an investor to decide to purchase any common stock, as the same may be varied in that Member State by any measure implementing the Prospectus Directive in that Member State and the expression “Prospectus Directive” means Directive 2003/71/EC and includes any relevant implementing measure in each Relevant Member State.

Each underwriter has represented, warranted and agreed that:

CERTAIN U.S. FEDERAL INCOME TAX CONSIDERATIONS

The following is a summary of certain U.S. federal income tax considerations arising from and relating to the acquisition, ownership, and disposition of our common shares to a U.S. Holder (as defined below) who acquires such common shares pursuant to this prospectus supplement. This discussion does not address the tax consequences to a subsequent purchaser of our common shares. This summary provides only general information and does not purport to be a complete analysis or listing of all potential U.S. federal income tax consequences that may apply to a U.S. Holder as a result of the acquisition, ownership, and disposition of our common shares. In addition, this summary does not take into account the individual facts and circumstances of any particular U.S. Holder that may affect the U.S. federal income tax consequences applicable to that U.S. Holder. Accordingly, this summary is not intended to be, and should not be construed as, legal or U.S. federal income tax advice with respect to any U.S. Holder. Each U.S. Holder should consult its own tax advisor regarding the U.S. federal, U.S. state and local, and non-U.S. tax consequences arising from or relating to the acquisition, ownership, and disposition of our common shares.

No legal opinion from U.S. legal counsel or ruling from the Internal Revenue Service, or IRS, has been requested, or will be obtained, regarding the U.S. federal income tax consequences to U.S. Holders of the acquisition, ownership, and disposition of our common shares. This summary is not binding on the IRS, and the IRS is not precluded from taking a position that is different from, and contrary to, the positions taken in this summary. In addition, because the authorities on which this summary is based are subject to various interpretations, the IRS and the U.S. courts could disagree with one or more of the positions taken in this summary.

Scope of this Disclosure

Authorities

This summary is based on the U.S. Internal Revenue Code of 1986, as amended, or the Code, U.S. Treasury Regulations promulgated thereunder (whether final, temporary or proposed), published IRS rulings, judicial decisions, published administrative positions of the IRS, and the Convention between Canada and the United States of America with Respect to Taxes on Income and on Capital, signed September 26, 1980, as amended (the Canada-U.S. Tax Treaty), in each case, as in effect as of the date of this prospectus supplement. Any of the authorities on which this summary is based could be changed in a material and adverse manner at any time, and any such change could be applied on a retroactive basis. Unless otherwise discussed, this summary does not discuss the potential effects, whether adverse or beneficial, of any proposed legislation.

U.S. Holders

For purposes of this summary, a “U.S. Holder” is a beneficial owner of common shares that, for U.S. federal income tax purposes, is (a) an individual who is a citizen or resident of the United States, (b) a corporation, or other entity classified as a corporation for U.S. federal income tax purposes, that is created or organized in or under the laws of the U.S., any state in the United States or the District of Columbia, (c) an estate if the income of such estate is subject to U.S. federal income tax regardless of the source of such income, or (d) a trust if (i) such trust has validly elected to be treated as a U.S. person for U.S. federal income tax purposes or (ii) a U.S. court is able to exercise primary supervision over the administration of such trust and one or more U.S. persons have the authority to control all substantial decisions of such trust.

U.S. Holders Subject to Special U.S. Federal Income Tax Rules Not Addressed

This summary does not address the U.S. federal income tax consequences applicable to U.S. Holders that are subject to special provisions under the Code, including, but not limited to, the following U.S. Holders: (a) U.S. Holders that are tax-exempt organizations, qualified retirement plans, individual retirement accounts, or other tax deferred accounts; (b) U.S. Holders that are financial institutions, insurance companies, real estate investment trusts, or regulated investment companies; (c) U.S. Holders that are dealers in securities or currencies or U.S. Holders that are traders in securities that elect to apply a mark-to-market accounting method; (d) U.S. Holders that have a “functional currency” other than the U.S. dollar; (e) U.S. Holders subject to the alternative minimum tax provisions of the Code; (f) U.S. Holders that own common shares as part of a straddle, hedging transaction, conversion transaction, integrated transaction, constructive sale, or other arrangement involving more than one position; (g) U.S. Holders that acquired common shares through the exercise of employee stock options or otherwise as compensation for services; (h) U.S. Holders that hold common shares other than as a capital asset within the meaning of Section 1221 of the Code; (i) U.S. Holders that beneficially own (directly, indirectly or by attribution) 10% or more of our equity securities (by vote or value); and (j) U.S. expatriates. U.S. Holders that are subject to special provisions under the Code, including U.S. Holders described above, should consult their own tax advisor regarding the U.S. federal, U.S. federal alternative minimum, U.S. federal estate and gift, U.S. state and local, and non-U.S. tax consequences arising from and relating to the acquisition, ownership, and disposition of the common shares.

If an entity or arrangement that is classified as a partnership for U.S. federal income tax purposes holds common shares, the U.S. federal income tax consequences to that partnership and the partners of that partnership generally will depend on the activities of the partnership and the status of the partners. Partners of entities that are classified as partnerships for U.S. federal income tax purposes should consult their own tax advisors regarding the U.S. federal income tax consequences arising from and relating to the acquisition, ownership and disposition of the common shares.

Tax Consequences Other than U.S. Federal Income Tax Consequences Not Addressed

This summary does not address the U.S. estate and gift, alternative minimum, state, local or non-U.S. tax consequences to U.S. Holders of the acquisition, ownership, and disposition of our common shares. Each U.S. Holder should consult its own tax advisor regarding the U.S. estate and gift, alternative minimum, state, local and non-U.S. tax consequences arising from and relating to the acquisition, ownership, and disposition of our common shares.

U.S. Federal Income Tax Considerations of the Acquisition, Ownership, and Disposition of Common Shares

Distributions on Common Shares

Subject to the discussion under “—Passive Foreign Investment Company Rules” below, a U.S. Holder that receives a distribution, including a constructive distribution or a taxable stock distribution, with respect to the common shares generally will be required to include the amount of that distribution in gross income as a dividend (without reduction for any Canadian income tax withheld from such distribution) to the extent of our current or accumulated “earnings and profits” (as computed for U.S. federal income tax purposes). To the extent that a distribution exceeds our current and accumulated “earnings and profits”, the excess amount will be treated (a) first, as a tax-free return of capital to the extent of a U.S. Holder’s adjusted tax basis in the common shares with respect to which the distribution is made (resulting in a corresponding reduction in the tax basis of those common shares) and, (b) thereafter, as gain from the sale or exchange of those common shares (see the more detailed discussion at “—Disposition of Common Shares” below). We do not intend to calculate our current or accumulated earnings and profits for U.S. federal income tax purposes and, therefore, will not be able to provide U.S. Holders with that information. U.S. Holders should therefore assume that any distribution by us with respect to our common shares will constitute a dividend. However, U.S. Holders should consult their own tax advisors regarding whether distributions from us should be treated as dividends for U.S. federal income tax purposes. Dividends paid on our common shares generally will not be eligible for the “dividends received deduction” allowed to corporations under the Code with respect to dividends received from U.S. corporations.

A dividend paid by us generally will be taxed at the preferential tax rates applicable to long-term capital gains if, among other requirements, (a) we are a “qualified foreign corporation” (as defined below), (b) the U.S. Holder receiving the dividend is an individual, estate, or trust, and (c) the dividend is paid on common shares that have been held by the U.S. Holder for at least 61 days during the 121-day period beginning 60 days before the “ex-dividend date” (i.e., the first date that a purchaser of the common shares will not be entitled to receive the dividend).

For purposes of the rules described in the preceding paragraph, we generally will be a “qualified foreign corporation”, or a QFC, if (a) we are eligible for the benefits of the Canada-U.S. Tax Treaty, or (b) our common shares are readily tradable on an established securities market in the United States, within the meaning provided in the Code. However, even if we satisfy one or more of the requirements, we will not be treated as a QFC if we are classified as a PFIC (as discussed below) for the taxable year during which we pay the applicable dividend or for the preceding taxable year. The dividend rules are complex, and each U.S. Holder should consult its own tax advisor regarding the application of those rules to them in their particular circumstances. Even if we satisfy one or more of the requirements, as noted below, there can be no assurance that we will not be a PFIC in the current taxable year, or become a PFIC in the future. Thus, there can be no assurance that we will qualify as a QFC.

Disposition of Common Shares

Subject to the discussion under “—Passive Foreign Investment Company Rules” below, a U.S. Holder will recognize gain or loss on the sale or other taxable disposition of common shares (that is treated as a sale or exchange for U.S. federal income tax purposes) equal to the difference, if any, between (a) the U.S. dollar value of the amount realized on the date of the sale or disposition and (b) the U.S. Holder’s adjusted tax basis (determined in U.S. dollars) in the common shares sold or otherwise disposed of. Any such gain or loss generally will be capital gain or loss, which will be long-term capital gain or loss if the common shares are held for more than one year. Each U.S. Holder should consult its own tax advisor as to the tax treatment of dispositions of common shares in exchange for Canadian dollars.

Preferential tax rates apply to long-term capital gains of a U.S. Holder that is an individual, estate, or trust. There are currently no preferential tax rates for long-term capital gains of a U.S. Holder that is a corporation. Deductions for capital losses are subject to complex limitations.

Passive Foreign Investment Company Rules

If we are or become a PFIC, the preceding sections of this summary may not describe the U.S. federal income tax consequences to U.S. Holders of the acquisition, ownership, and disposition of our common shares.

Passive Foreign Investment Company Status.

Special, generally unfavorable, rules apply to the ownership and disposition of the stock of a PFIC. For U.S. federal income tax purposes, a non-U.S. corporation is classified as a PFIC for each taxable year in which either:

Passive income includes the following types of income:

In determining whether we are a PFIC, we will be required to take into account a pro rata portion of the income and assets of each corporation in which we own, directly or indirectly, at least 25% by value.

As described above, PFIC status of a non-U.S. corporation for a taxable year depends on the relative values of certain categories of assets and the relative amount of certain kinds of income. Therefore, our status as a PFIC for any given taxable year depends upon the financial results for such year and upon relative valuations, which are subject to change and beyond our ability to predict or control. Based on our most recent financial statements and projections and given uncertainty regarding the composition of our future income and assets, there is a significant risk that we may be classified as a PFIC for our current taxable year and possibly subsequent years. However, PFIC status is fundamentally factual in nature, depends on the application of complex U.S. federal income tax rules (which are subject to differing interpretations), generally cannot be determined until the close of the taxable year in question and is determined annually. Accordingly, there can be no assurance that we will not be a PFIC in our current taxable year or subsequent years. The PFIC rules are complex, and each U.S. Holder should consult its tax advisor regarding the application of the PFIC rules to us.

Default PFIC Rules Under Section 1291 of the Code.

Generally, if we are or have been treated as a PFIC for any taxable year during a U.S. Holder’s holding period of common shares, subject to the special rules described below applicable to a U.S. Holder who makes a Mark-to-Market Election or a QEF Election (each as defined below), any “excess distribution” with respect to the common shares would be allocated ratably over the U.S. Holder’s holding period. The amounts allocated to the taxable year of the excess distribution and to any year before we became a PFIC would be taxed as ordinary income. The amount allocated to each other taxable year would be subject to tax at the highest rate in effect for individuals or corporations in that taxable year, as appropriate, and an interest charge would be imposed on the amount allocated to that taxable year. Distributions made in respect of common shares during a taxable year will be excess distributions to the extent they exceed 125% of the average of the annual distributions on common shares received by the U.S. Holder during the preceding three taxable years or the U.S. Holder’s holding period, whichever is shorter. In addition, dividends generally will not be qualified dividend income if we are a PFIC in the taxable year of payment or the preceding year.

Generally, if we are treated as a PFIC for any taxable year during which a U.S. Holder owns common shares, any gain on the disposition of the common shares would be treated as an excess distribution and would be allocated ratably over the U.S. Holder’s holding period and subject to taxation in the same manner as described in the preceding paragraph, and would not be eligible for the preferential long-term capital gains rate.

Certain elections (including the Mark-to-Market Election and the QEF Election, as defined and discussed below) may sometimes be used to mitigate the adverse impact of the PFIC rules on U.S. Holders, but these elections may accelerate the recognition of taxable income and have other adverse results.

U.S. HOLDERS ARE URGED TO CONSULT THEIR TAX ADVISORS REGARDING THE POSSIBLE APPLICABILITY OF THE PFIC RULES TO SHARES ACQUIRED PURSUANT TO THIS PROSPECTUS SUPPLEMENT, AND THE AVAILABILITY OF MAKING A QEF OR MARK-TO-MARKET ELECTION TO MITIGATE ADVERSE U.S. TAX CONSEQUENCES OF HOLDING SHARES OF A PFIC.

QEF Election.

A U.S. Holder of common shares in a PFIC generally would not be subject to the PFIC rules discussed above if the U.S. Holder had made a timely and effective election (a “QEF Election”) to treat us as a “qualified electing fund” (a “QEF”). Instead, such U.S. Holder would be subject to U.S. federal income tax on its pro rata share of our (i) net capital gain, which would be taxed as long-term capital gain to such U.S. Holder, and (ii) ordinary earnings, which would be taxed as ordinary income to such U.S. Holder, in each case regardless of whether such amounts are actually distributed to such U.S. Holder. However, a U.S. Holder that makes a QEF Election may, subject to certain limitations, elect to defer payment of current U.S. federal income tax on such amounts, subject to an interest charge. If such U.S. Holder is not a corporation, any such interest paid will be treated as “personal interest,” which is not deductible.

A U.S. Holder that makes a timely and effective QEF Election generally (a) may receive a tax-free distribution from us to the extent that such distribution represents our “earnings and profits” that were previously included in income by such U.S. Holder because of such QEF Election and (b) will adjust such U.S. Holder’s tax basis in the common shares to reflect the amount included in income or allowed as a tax-free distribution because of such QEF Election. In addition, for U.S. federal income tax purposes, a U.S. Holder that makes a timely QEF Election generally will recognize capital gain or loss on the sale or other taxable disposition of the common shares.

A QEF Election will be treated as “timely” if such QEF Election is made for the first taxable year in the U.S. Holder’s holding period for the common shares in which we are a PFIC. A U.S. Holder may make a timely QEF election by filing the appropriate QEF Election documents at the time such U.S. Holder files a U.S. federal income tax return for such first year. If a U.S. Holder makes a QEF Election after the first taxable year in the U.S. Holder’s holding period for the common shares in which we are a PFIC, then, in addition to filing the QEF Election documents, a U.S. Holder may elect to recognize gain (which will be taxed under the rules discussed under “—Default PFIC Rules Under Section 1291 of the Code”) as if the common shares were sold on the qualification date. The “qualification date” is the first day of the first taxable year in which we are a QEF with respect to such U.S. Holder. The election to recognize such gain can only be made if such U.S. Holder’s holding period for the common shares includes the qualification date. By electing to recognize such gain, such U.S. Holder will be deemed to have made a timely QEF Election. In addition, under very limited circumstances, it is possible that a U.S. Holder might make a retroactive QEF Election if such U.S. Holder failed to file the QEF Election documents in a timely manner. If a U.S. Holder fails to make a QEF Election for the first taxable year in the U.S. Holder’s holding period for the common shares in which we are a PFIC and does not elect to recognize gain as if the common shares were sold on the qualification date, such holder will not be treated as having made a “timely” QEF election and will continue to be subject to the special adverse taxation rules discussed above under “—Default PFIC Rules Under Section 1291 of the Code”.

A QEF Election will apply to the taxable year for which such QEF election is made and to all subsequent taxable years, unless such QEF Election is invalidated or terminated or the IRS consents to revocation of such QEF Election. If a U.S. Holder makes a QEF Election and, in a subsequent taxable year, we cease to be a PFIC, the QEF Election will remain in effect (although it will not be applicable) during those taxable years in which we are not a PFIC. Accordingly, if we become a PFIC in another subsequent taxable year, the QEF Election will be effective and the U.S. Holder will be subject to the rules described above during any such subsequent taxable year in which we qualify as a PFIC.

A U.S. Holder cannot make and maintain a valid QEF Election unless we provide certain U.S. tax information necessary to make such an election. On an annual basis, we intend to use commercially reasonable efforts to make available to U.S. Holders that acquire common shares pursuant to this prospectus supplement, upon their written request (a) timely information as to our status as a PFIC, and (b) for each year in which we are a PFIC, information and documentation that a U.S. Holder making a QEF Election with respect to us is required to obtain for U.S. federal income tax purposes. Each U.S. Holder should consult its own tax advisor regarding the availability of, and procedure for making, a QEF Election with respect to us.

Mark-to-Market Election.

A U.S. Holder of common shares in a PFIC would not be subject to the PFIC rules discussed above under “—Default PFIC Rules Under Section 1291 of the Code” if the U.S. Holder had made a timely and effective election to mark the PFIC common shares to market (a “Mark-to-Market Election”).

A U.S. Holder may make a Mark-to-Market Election with respect to the common shares only if such shares are marketable stock. Such shares generally will be “marketable stock” if they are regularly traded on a “qualified exchange,” which is defined as (a) a national securities exchange that is registered with the Securities and Exchange Commission, (b) the national market system established pursuant to section 11A of the Exchange Act of 1934, or (c) a non-U.S. securities exchange that is regulated or supervised by a governmental authority of the country in which the market is located, provided that (i) such non-U.S. exchange has trading volume, listing, financial disclosure, surveillance, and other requirements, and the laws of the country in which such non-U.S. exchange is located, together with the rules of such non-U.S. exchange, ensure that such requirements are actually enforced and (ii) the rules of such non-U.S. exchange ensure active trading of listed stocks. Our common shares will generally be treated as “regularly traded” in any calendar year in which more than a de minimis quantity of common shares is traded on a qualified exchange for at least 15 days during each calendar quarter. Each U.S. Holder should consult its own tax advisor with respect to the availability of a Mark-to-Market Election with respect to the common shares.

In general, a U.S. Holder that makes a timely Mark-to-Market Election with respect to the common shares will include in ordinary income, for each taxable year in which we are a PFIC, an amount equal to the excess, if any, of (a) the fair market value of the common shares as of the close of such taxable year over (b) such U.S. Holder’s tax basis in such shares. A U.S. Holder that makes a Mark-to-Market Election will be allowed a deduction in an amount equal to the lesser of (a) the excess, if any, of (i) such U.S. Holder’s adjusted tax basis in the common shares over (ii) the fair market value of such shares as of the close of such taxable year or (b) the excess, if any, of (i) the amount included in ordinary income because of such Mark-to-Market Election for prior taxable years over (ii) the amount allowed as a deduction because of such Mark-to-Market Election for prior taxable years. If a U.S. Holder makes a Mark-to-Market Election after the first taxable year in which we are a PFIC and such U.S. Holder has not made a timely QEF Election with respect to us, the PFIC rules described above under “—Default PFIC Rules Under Section 1291 of the Code” will apply to certain dispositions of, and distributions on, the common shares, and the U.S. Holder’s mark-to-market income for the year of the election. If we were to cease being a PFIC, a U.S. Holder that marked its common shares to market would not include mark-to-market gain or loss with respect to its common shares for any taxable year that we were not a PFIC.

A U.S. Holder that makes a Mark-to-Market Election generally will also adjust such U.S. Holder’s tax basis in his common shares to reflect the amount included in gross income or allowed as a deduction because of such Mark-to-Market Election. In addition, upon a sale or other taxable disposition of the common shares subject to a Mark-to-Market Election, any gain or loss on such disposition will be ordinary income or loss (to the extent that such loss does not to exceed the excess, if any, of (a) the amount included in ordinary income because of such Mark-to-Market Election for prior taxable years over (b) the amount allowed as a deduction because of such Mark-to-Market Election for prior taxable years). A Mark-to-Market Election applies to the taxable year in which such Mark-to-Market Election is made and to each subsequent taxable year, unless the common shares cease to be “marketable stock” or the IRS consents to revocation of such election. Each U.S. Holder should consult its own tax advisor regarding the availability of, and procedure for making, a Mark-to-Market Election with respect to the common shares.

Reporting. If we were to be treated as a PFIC in any taxable year, a U.S. Holder will generally be required to file an annual report with the IRS containing such information as the U.S. Treasury Department may require.

Each U.S. Holder should consult its own tax advisor regarding our potential status as a PFIC, the possible effect of the PFIC rules to such holder and information reporting required if we were a PFIC, as well as the availability of any election that may be available to the holder to mitigate adverse U.S. federal income tax consequences of holding shares in a PFIC.

Receipt of Foreign Currency

The amount of a distribution paid in Canadian dollars or Canadian dollar proceeds received on the sale or other taxable disposition of common shares will generally be equal to the U.S. dollar value of the currency on the date of receipt. If any Canadian dollars received with respect to the common shares are later converted into U.S. dollars, U.S. Holders may realize gain or loss on the conversion. Any gain or loss generally will be treated as ordinary income or loss and generally will be from sources within the United States for U.S. foreign tax credit purposes. Each U.S. Holder should consult its own tax advisor concerning the possibility of foreign currency gain or loss if any such currency is not converted into U.S. dollars on the date of receipt.

Foreign Tax Credit

Subject to certain limitations, a U.S. Holder who pays (whether directly or through withholding) Canadian or other non-U.S. income tax with respect to the common shares may be entitled, at the election of the U.S. Holder, to receive either a deduction or a credit for Canadian or other non-U.S. income tax paid. Dividends paid on common shares generally will constitute income from sources outside the United States. The foreign tax credit rules (including the limitations with respect thereto) are complex, and each U.S. Holder should consult its own tax advisor regarding the foreign tax credit rules, having regard to such holder’s particular circumstances.

Information Reporting; Backup Withholding

Generally, information reporting and backup withholding will apply to distributions on, and the payment of proceeds from the sale or other taxable disposition of, the common shares unless (i) the U.S. Holder is a corporation or other exempt entity, or (ii) in the case of backup withholding, the U.S. Holder provides a correct taxpayer identification number and certifies that the U.S. Holder is not subject to backup withholding.

Backup withholding is not an additional tax. Any amount withheld generally will be creditable against a U.S. Holder’s U.S. federal income tax liability or refundable to the extent that it exceeds such liability provided the required information is provided to the IRS in a timely manner.

In addition, certain categories of U.S. Holders must file information returns with respect to their investment in a non-U.S. corporation. For example, certain U.S. Holders must file IRS Form 8938 with respect to certain “specified foreign financial assets” (such as the common shares) with an aggregate value in excess of US$50,000 (and, in some circumstances, a higher threshold). Failure to do so could result in substantial penalties and in the extension of the statute of limitations with respect to such holder’s U.S. federal income tax returns. Each U.S. Holder should consult its own tax advisor regarding application of the information reporting and backup withholding rules to it in connection with an investment in our common shares.

Medicare Contribution Tax

U.S. Holders that are individuals, estates or certain trusts generally will be subject to a 3.8% Medicare contribution tax on, among other things, dividends on, and capital gains from the sale or other taxable disposition of, common shares, subject to certain limitations and exceptions. Each U.S. Holder should consult its own tax advisor regarding possible application of this additional tax to income earned in connection with an investment in our common shares.

CERTAIN CANADIAN FEDERAL INCOME TAX CONSIDERATIONS

The following is, as of the date hereof, a summary of the principal Canadian federal income tax considerations generally applicable under the Income Tax Act (Canada) and the regulations promulgated thereunder (collectively the “Tax Act”), to a purchaser who acquires, as beneficial owner, the offered shares under this offering, and who, for purposes of the Tax Act and at all relevant times, (i) is not, and is not deemed to be, resident in Canada, (ii) holds the offered shares as capital property, (iii) deals at arm’s length with, and is not affiliated with, Acasti or the Underwriters, and (iv) does not use or hold and will not be deemed to use or hold, the offered shares in a business carried on in Canada (a “Non-Resident Holder”). Special rules, which are not discussed in this summary, may apply to an insurer that carries on an insurance business in Canada and elsewhere. Such Non-Resident Holders should consult their own tax advisors.

This summary is based upon the provisions of the Tax Act in force as of the date hereof, all specific proposals to amend the Tax Act that have been publicly announced by or on behalf of the Minister of Finance (Canada) prior to the date hereof (the “Proposed Amendments”), the Canada-United States Tax Convention (1980), as amended (the “Canada-U.S. Tax Treaty”), and an understanding of the current administrative policies and assessing practices of the Canada Revenue Agency (the “CRA”), published in writing by it prior to the date hereof. This summary assumes the Proposed Amendments will be enacted in the form proposed. However, no assurance can be given that the Proposed Amendments will be enacted in their current form, or at all. This summary is not exhaustive of all possible Canadian federal income tax considerations and, except for the Proposed Amendments, does not take into account or anticipate any changes in the law or any changes in the CRA’s administrative policies or assessing practices, whether by legislative, governmental or judicial action or decision, nor does it take into account or anticipate any other federal or any provincial, territorial or foreign tax considerations, which may differ significantly from those discussed herein.

This summary is not applicable to a Non-Resident Holder who makes or has made a “functional currency” reporting election; or that has entered or enters into a “derivative forward agreement” with respect to the offered shares (each as defined in the Tax Act). Any such Non-Resident Holder should consult its own tax advisor with respect to an investment in the offered shares. This summary is of a general nature only and is not intended to be, nor should it be construed to be, legal or tax advice to any prospective purchaser or holder of the offered shares, and no representations with respect to the income tax consequences to any prospective purchaser or holder are made. Consequently, prospective purchasers or holders of the offered shares should consult their own tax advisors with respect to their particular circumstances.

Currency Conversion

Generally, for purposes of the Tax Act, all amounts relating to the acquisition, holding or disposition of the offered shares and warrants must be converted into Canadian dollars based on the exchange rates as determined in accordance with the Tax Act. The amounts subject to withholding tax and any capital gains or capital losses realized by a Non-Resident Holder may be affected by fluctuations in the Canadian-U.S. dollar exchange rate.

Dispositions

A Non-Resident Holder will not be subject to tax under the Tax Act on a capital gain realized on a disposition or deem disposition of an offered share, unless the offered share constitutes “taxable Canadian property” (as defined in the Tax Act) of the Non-Resident Holder at the time of disposition and the Non-Resident Holder is not entitled to relief under an applicable income tax treaty or convention.

Provided the offered shares are listed on a “designated stock exchange”, as defined in the Tax Act (which currently includes the TSXV and NASDAQ) at the time of disposition, the offered shares will generally not constitute taxable Canadian property of a Non-Resident Holder at that time, unless at any time during the 60-month period immediately preceding the disposition the following two conditions are satisfied concurrently: (i) (a) the Non-Resident Holder; (b) persons with whom the Non-Resident Holder did not deal at arm’s length (within the meaning of the Tax Act); (c) partnerships in which the Non-Resident Holder or a person described in (b) holds a membership interest directly or indirectly through one or more partnerships; or (d) any combination of the persons and partnerships described in (a) through (c), owned 25% or more of the issued shares of any class or series of the shares of Acasti; and (ii) more than 50% of the fair market value of the shares of Acasti was derived directly or indirectly from one or any combination of: real or immovable property situated in Canada, “Canadian resource properties”, “timber resource properties” (each as defined in the Tax Act), and options in respect of, or interests in or for civil law rights in, any such properties. Notwithstanding the foregoing, in certain circumstances set out in the Tax Act, the offered shares could be deemed to be taxable Canadian property. Even if the offered shares are taxable Canadian property to a Non-Resident Holder, such Non-Resident Holder may be exempt from tax under the Tax Act on the disposition of such common shares by virtue of an applicable income tax treaty or convention. A Non-Resident Holder contemplating a disposition of offered shares that may constitute taxable Canadian property should consult a tax advisor prior to such disposition.

Dividends

Dividends paid or credited on the offered shares or deemed to be paid or credited on the offered shares to a Non-Resident Holder will be subject to Canadian withholding tax under the Tax Act at a rate of 25% on the gross amount of the dividend, although such rate may be reduced under the provisions of an applicable income tax convention between Canada and the Non-Resident Holder’s country of residence. For example, where dividends on the offered shares are considered to be paid to or derived by a Non-Resident Holder that is the beneficial owner of the dividends and is a U.S. resident for the purposes of, and is entitled to benefits of, the Canada-U.S. Tax Treaty, the applicable rate of Canadian withholding tax is generally reduced to 15%. Not all persons who are U.S. residents will qualify for the benefits of the Canada-U.S. Tax Treaty. Non-Resident Holders are advised to consult their own tax advisors in this regard.

ENFORCEMENT OF CIVIL LIABILITIES

We are incorporated under the laws of the Province of Québec. Substantially all of our assets are located outside the United States. In addition, several of our directors and officers are nationals and/or residents of countries other than the United States, and all or a substantial portion of such persons’ assets may be located outside the United States. As a result, it may be difficult for investors to effect service of process within the United States upon us or such persons or to enforce against them or against us, judgments obtained in United States courts, including judgments predicated upon the civil liability provisions of the securities laws of the United States or any state thereof. In addition, investors should not assume that the courts of Canada (i) would enforce judgments of U.S. courts obtained in actions against us, our officers or directors, or other said persons, predicated upon the civil liability provisions of the U.S. federal securities laws or other laws of the United States or (ii) would enforce, in original actions, liabilities against us or such directors, officers or experts predicated upon the United States federal securities laws or any securities or other laws of any state or jurisdiction of the United States.

We have been advised by Osler, Hoskin & Harcourt LLP, that there is doubt whether an action could be brought in Canada in the first instance on the basis of liability predicated solely upon United States federal securities laws.

We have appointed C T Corporation System as our agent to receive service of process with respect to any action brought against us in the United States.

LEGAL MATTERS

Certain legal matters related to this offering will be passed upon on for us by Osler, Hoskin & Harcourt LLP, Montreal, Québec, Canada and Osler, Hoskin & Harcourt LLP, New York, New York. Certain legal matters in connection with this offering will be passed upon for the underwriters by Mintz, Levin, Cohn, Ferris, Glovsky and Popeo PC, New York, New York.

EXPERTS

The financial statements of Acasti Pharma Inc. as at March 31, 2018 and 2017, and for the year ended March 31, 2018, the thirteen-month period ended March 31, 2017 and the year ended February 29, 2016, have been included herein and in the accompanying prospectus in reliance upon the report of KPMG LLP, independent registered public accounting firm, appearing elsewhere herein and upon the authority of said firm as experts in accounting and auditing.

The audit report dated June 27, 2018 on these financial statements contains an explanatory paragraph that states that Acasti Pharma Inc. has incurred operating losses and negative cash flows from operations since inception, that its current assets are projected to be significantly less than what will be needed, and that it needs to obtain additional financing, which indicate the existence of a material uncertainty that casts substantial doubt about its ability to continue as a going concern. The financial statements do not include any adjustments that may be necessary if the going concern basis was not appropriate. It also contains an explanatory paragraph that states that the financial statements of Acasti Pharma Inc. as at February 28, 2017 and for the twelve-month and one-month periods ended February 28, 2017 and March 31, 2017 respectively are unaudited and accordingly, we do not express an opinion on them.

DOCUMENTS INCORPORATED BY REFERENCE

The SEC allows us to “incorporate by reference” into the prospectus the documents we file with or furnish to them, which means that we can disclose important information to you by referring you to these documents. The information that we incorporate by reference into the prospectus forms a part of the prospectus. We incorporate by reference into the prospectus the documents listed below:

All documents filed with the SEC by us pursuant to Section 13(a), 13(c), 14 or 15(d) of the Securities Exchange Act of 1934, as amended, or Exchange Act, subsequent to the date of this prospectus supplement and prior to the termination of the offering of the common shares hereunder shall be deemed to be incorporated herein by reference and to be a part hereof from the date of filing of such documents.  Any statement contained in any document incorporated or deemed to be incorporated by reference herein shall be deemed to be modified or superseded for purposes of this prospectus supplement to the extent that a statement contained herein or in any other subsequently filed document which also is or is deemed to be incorporated by reference herein modifies or supersedes such statement.  Any such statement so modified or superseded shall not be deemed, except as modified or superseded, to constitute a part of this prospectus supplement.

Any person receiving a copy of the prospectus, including any beneficial owner, may obtain without charge, upon written or oral request, a copy of any of the documents incorporated by reference into the prospectus, except for the exhibits to those documents unless the exhibits are specifically incorporated by reference into those documents. Requests should be directed to our principal executive offices, 545 Promenade du Centropolis, Suite 100, Laval, Québec, Canada H7T 0A3, attention: Chief Financial Officer (telephone: (450) 686-4555).

WHERE YOU CAN FIND MORE INFORMATION

We have filed with the SEC a registration statement on Form F-3 (File No. 333-223464), of which this prospectus supplement and the accompanying prospectus form a part, under the Securities Act of 1933, as amended, to register our common shares offered by this prospectus supplement. This prospectus supplement and the accompanying prospectus do not contain all of the information contained in the registration statement and the exhibits and schedules to the registration statement. For further information about us and the common shares, please refer to the registration statement, including the exhibits to the registration statement. The exhibits to the registration statement provide more details of the matters discussed in this prospectus supplement and the accompanying prospectus.

We are subject to the informational requirements of the Exchange Act, and we file reports and other information with the SEC. You may read and copy any of our reports and other information at, and obtain copies upon payment of prescribed fees from, the Public Reference Room maintained by the SEC at 100 F Street, N.E., Washington, DC 20549. In addition, the SEC maintains a web site that contains reports and other information regarding registrants that file electronically with the SEC at http://www.sec.gov. The public may obtain information on the operation of the Public Reference Room by calling the SEC at 1-800-SEC-0330.

As a foreign private issuer, we are exempt under the Exchange Act from, among other things, certain rules prescribing the furnishing and content of proxy statements, and our executive officers, directors and principal shareholders are exempt from the reporting and short-swing profit recovery provisions contained in Section 16 of the Exchange Act. In addition, we are not required under the Exchange Act to file periodic reports and financial statements with the SEC as frequently or as promptly as U.S. companies whose securities are registered under the Exchange Act.

We are also subject to the full informational requirements of the securities commissions in all provinces of Canada, and you are also invited to read and copy any reports, statements or other information, other than confidential filings, that we file with the Canadian provincial securities commissions. These filings are also electronically available from the Canadian System for Electronic Document Analysis and Retrieval (SEDAR) at www.sedar.com, the Canadian equivalent of the SEC’s electronic document gathering and retrieval system.

We maintain a corporate website at http://www.acastipharma.com. Information contained on, or that can be accessed through, our website does not constitute a part of this prospectus.

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Common Shares

Prospectus Supplement

Sole Book-Running Manager

Oppenheimer & Co.

Co-Manager

Aegis Capital Corp.

The date of this prospectus supplement is               , 2018.