iBio Inc美股招股说明书(2025-08-18版)

Filed Pursuant to Rule424(b)(5)Registration No.333-280680 PRELIMINARY PROSPECTUS SUPPLEMENT(To Prospectus dated August6, 2024) iBio, Inc. Pre-Funded Warrants to Purchase up toShares of Common StockSeriesG Warrants to Purchase (i)up toShares of Common Stock, or Pre-Funded Warrants in Lieu Thereof, and (ii)SeriesHWarrants to Purchase up toShares of Common Stock, or Pre-Funded Warrants in Lieu ThereofSeriesH Warrants, Issuable Upon Exercise of Series G Warrants, to Purchase up toShares of Common Stock, or Pre-FundedWarrants in Lieu ThereofShares of Common Stock Issuable Upon Exercise of the Pre-Funded Warrants, SeriesG Warrants, and SeriesH Warrants We are offering pre-funded warrants to purchase an aggregate of up toshares of our common stock, par value $0.001 per share (“commonstock” and such warrants, the “pre-funded warrants”) and accompanying SeriesG warrants (the “SeriesG warrants”) to purchase (i)an aggregate ofup toshares of our common stock (or, for those investors who so choose, pre-funded warrants in lieu thereof) and (ii)SeriesH warrants topurchase an aggregate of up toshares of our common stock (or, for those investors who so choose, pre-funded warrants in lieu thereof) (the“SeriesH warrants”). The pre-funded warrants will be sold in a fixed combination with the SeriesG warrants, with each pre-funded warrant that we sell in this offeringbeing accompanied by a SeriesG warrant to purchase (i)of a share of common stock (or, for those investors who so choose, a pre-fundedwarrant in lieu thereof) and (ii)a SeriesH warrant to purchaseof a share of common stock (or, for those investors who so choose, a pre-funded warrant in lieu thereof), at a combined public offering price of $. The pre-funded warrants and SeriesG warrants (and, upon exercise ofthe SeriesG warrants, the shares of common stock and SeriesH warrants underlying the SeriesG warrants) are immediately separable and will beissued separately, but can only be purchased together in this offering or upon the exercise of the SeriesG warrants, as applicable. Each pre-fundedwarrant will have an exercise price per share of common stock equal to $0.001 and will be immediately exercisable for one share of common stock,subject to certain beneficial ownership and other limitations. The SeriesG warrants and SeriesH warrants will each be exercisable from their date ofissuance and will have an exercise price equal to $per share of common stock (or $per pre-funded warrant) and in the case of the SeriesGwarrants, the accompanying SeriesH warrant. The SeriesG warrants will expire on the date that is the earlier of (i)30 trading days following ourpublic announcement, via a press release on a nationally recognized news wire or the filing of a Current Report on Form8-K with the Securities andExchange Commission (the “SEC”), that an Investigational New Drug Application (“IND”) filed with the U.S. Food and Drug Administration (the“FDA”), a Clinical Trial Notification filed with the applicable foreign governmental body in Australia, a Clinical Trial Application filed with theEuropean Medicines Agency, or an equivalent submission filed with a foreign governmental body to initiate a clinical trial in any other foreignjurisdiction, has been accepted or has otherwise gone into effect, as applicable (such public filing or announcement, the “Trial Initiation Milestone”)and (ii)five years from the date of issuance. In addition, to the extent the proportion of the unexercised portion of the Series G Warrant relative to theoriginally issued Series G Warrant is greater than the proportion of the unexercised portion of the Pre-Funded Warrant relative to the originally issuedPre-Funded Warrant each SeriesG warrant will immediately expire in proportion to the extent that the corresponding pre-funded warrant held by aholder is exercised prior to the occurrence of the Trial Initiation Milestone. When issued upon exercise of the SeriesG warrants, the SeriesH warrantswill expire on the four-year anniversary of the closing date of this offering. The pre-funded warrants, SeriesG warrants and the SeriesH warrants arereferred to collectively in this prospectus supplement as the “warrants.” We refer to the warrants together with the common stock underlying thewarrants, collectively, as the “securities.” This prospectus supplement also relates to the offering of the SeriesH warrants underlying the SeriesGwarrants and the shares of common stock issuable upon the exercise of the pre-funded warrants, the SeriesG warrants and the SeriesH warrants. See“Description of Securities We Are Offering.” Our common stock is listed on the Nasdaq Capital Market under the symbol “IBIO.” On August15, 2025, the last reported sale price of ourcommon stock on the Nasdaq Capital Market was $0.74 per share. There is no established public trading market for the warrants and we do notexpect a market to develop. We do not intend to list the warrants on the Nasdaq Capital Market, any other national securities e