Milestone Pharmaceuticals Inc美股招股说明书(2025-07-14版)

We are offering an aggregate of 31,500,000 common shares and, in lieu of common shares to certain investors that so choose, pre-funded warrants, or Pre-Funded Warrants, to purchase an aggregate of 3,502,335 common shares, and accompanying SeriesA common warrants to purchase an aggregate of35,002,335 common shares, or Series A Common Warrants, and Series B common warrants to purchase an aggregate of 35,002,335 common shares, orSeries B Common Warrants and, together with the Series A Common Warrants, the Common Warrants. Each common share is being offered and sold together with (i) an accompanying Series A Common Warrant to purchase one common share and (ii) anaccompanying Series B Common Warrant to purchase one common share at a combined offering price of $1.50, and each Pre-Funded Warrant is beingoffered and sold together with (i) an accompanying Series A Common Warrant to purchase one common share and (ii) an accompanying Series B CommonWarrant to purchase one common share at a combined offering price of $1.499, which is equal to the combined offering price per common share andaccompanying Common Warrant less the $0.001 exercise price of each Pre-Funded Warrant. The common shares and the Pre-Funded Warrants, on the one hand, and the accompanying Common Warrants, on the other hand, are immediately separableand will be issued separately, but can only be purchased together in this offering. Each Pre-Funded Warrant will have an exercise price per common shareequal to $0.001 and will be exercisable immediately and will not expire until exercised in full. The SeriesA Common Warrants will be exercisable immediatelyand will expire one year from the date of issuance. The Series B Common Warrants will be exercisable immediately and will expire five years from the date ofissuance. The Series B Common Warrants allow us to force the exercise of such SeriesB Common Warrants upon certain stock price requirements. TheSeries A Common Warrants will have an exercise price of $1.50 per common share, and the Series B Common Warrants will have an exercise price of $1.875per common share, in each case subject to adjustment as described elsewhere in this prospectus supplement. This prospectus supplement also relates to the offering of the common shares issuable upon the exercise of the Pre-Funded Warrants and each series ofCommon Warrants. The Common Warrants, together with the Pre-Funded Warrants, shall be referred to herein as the Warrants. The common sharesunderlying the Warrants shall be referred to herein as the Warrant Shares. Our common shares trade on the Nasdaq Global Select Market under the symbol “MIST.” On July11, 2025, the last reported sale price of our common shareswas $1.56 per share. There is no established public trading market for the Warrants, and we do not expect a market to develop. We do not intend to list theWarrants on the Nasdaq Global Select Market or on any other national securities exchange or nationally recognized trading system. Without an active tradingmarket, the liquidity of the Warrants will be limited. Certain of our directors have indicated an interest in purchasing an aggregate of up to 453,331 common shares and accompanying Series A Common Warrantsto purchase 453,331 common shares and Series B Common Warrants to purchase 453,331 common shares in this offering at the public offering price and onthe same terms and conditions as the other purchasers in this offering. However, because indications of interest are not binding agreements or commitments topurchase, the underwriters could determine to sell more, fewer or no common shares and accompanying Common Warrants to any of these potentialpurchasers, and any of these potential purchasers could determine to purchase more, fewer or no common shares and accompanying Common Warrants inthis offering. The underwriters will receive the same underwriting discounts and commissions on any common shares and accompanying Common Warrantspurchased by these parties as they will on any other common shares and accompanying Common Warrants sold to the public in this offering.We are a “smaller reporting company” as defined under federal securities laws and, as such, have elected to comply with certain reduced public company reporting requirements for this prospectus supplement, the accompanying prospectus, and the documents incorporated by reference herein and may elect tocomply with reduced public company reporting requirements in future filings. See “Prospectus Supplement Summary—Implications of Being a SmallerReporting Company and a Non-Accelerated Filer.” Investing in our securities involves a high degree of risk. See “Risk Factors” beginning on pageS-10of this prospectus supplement and undersimilar headings in the accompanying prospectus and any related free writing prospectus we have authorized for use in connection with thisoffering and the other documents that are incorporated by reference into this prospectus supplement concerning factors you shou