Outlook Therapeutics Inc美股招股说明书(2026-05-13版)

Common Stock We have entered into a sales agreement dated May 13, 2026, or the Sales Agreement, with H.C. Wainwright & Co., LLC, orWainwright, relating to the issuance and sale of shares of our common stock, par value $0.01 per share, offered by this prospectussupplement and the accompanying prospectus. In accordance with the terms of the Sales Agreement, we may offer and sell shares ofcommon stock having an aggregate offering price of up to $100,000,000 from time to time through or to Wainwright acting as ouragent or principal. Sales of our common stock, if any, under this prospectus supplement may be made in sales deemed to be “at the market offerings”as defined in Rule 415 promulgated under the Securities Act of 1933, as amended, or the Securities Act. Wainwright is not required tosell any specific number or dollar amount of securities, but will act as a sales agent using commercially reasonable efforts consistentwith its normal trading and sales practices, on mutually agreed terms between Wainwright and us. There is no arrangement for funds tobe received in any escrow, trust or similar arrangement. We will pay Wainwright a commission equal to 3% of the gross proceeds from the sale of common stock issued by us and soldthrough Wainwright as sales agent under the Sales Agreement. See the section titled “Plan of Distribution” for additional informationregarding the compensation to be paid to Wainwright. In connection with the sale of the common stock on our behalf, Wainwright willbe deemed to be an “underwriter” within the meaning of the Securities Act, and the compensation payable to Wainwright will bedeemed underwriting commissions or discounts. We have also agreed to provide indemnification and contribution to Wainwright withrespect to certain liabilities, including liabilities under the Securities Act and the Securities Exchange Act of 1934, as amended, or theExchange Act. Our common stock is listed on The Nasdaq Capital Market under the symbol “OTLK.” On May 12, 2026, the last reported saleprice of our common stock on The Nasdaq Capital Market was $0.2425 per share. We are a “smaller reporting company” under the federal securities laws and, as such, are subject to reduced public companydisclosure standards for this prospectus supplement and future filings. See the section entitled “Prospectus Supplement Summary—Implications of Being a Smaller Reporting Company” for additional information. Investing in our common stock involves a high degree of risk. See the section titled “Risk Factors” on page S-7 of thisprospectus supplement and any similar section contained in the accompanying prospectus and in the documents that areincorporated by reference herein and therein. Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved ofthese securities or determined if this prospectus supplement or the accompanying prospectus is truthful or complete. Anyrepresentation to the contrary is a criminal offense. H.C. Wainwright & Co. The date of this prospectus supplement is May 13, 2026 TABLE OF CONTENTS Prospectus Supplement ABOUT THIS PROSPECTUS SUPPLEMENTS-2PROSPECTUS SUPPLEMENT SUMMARYS-3THE OFFERINGS-6RISK FACTORSS-7SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTSS-13USE OF PROCEEDSS-15DILUTIONS-16PLAN OF DISTRIBUTIONS-18LEGAL MATTERSS-20EXPERTSS-20WHERE YOU CAN FIND MORE INFORMATIONS-20INCORPORATION OF CERTAIN INFORMATION BY REFERENCES-21 Prospectus ABOUT THIS PROSPECTUSiiPROSPECTUS SUMMARY1THE SECURITIES WE MAYOFFER4RISK FACTORS7SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS8USE OF PROCEEDS9DESCRIPTION OF CAPITAL STOCK10DESCRIPTION OF DEBT SECURITIES16DESCRIPTION OF WARRANTS23LEGAL OWNERSHIP OF SECURITIES25PLAN OF DISTRIBUTION28LEGAL MATTERS30EXPERTS30WHERE YOU CAN FIND MORE INFORMATION30INCORPORATION OF CERTAIN INFORMATION BY REFERENCE31 ABOUT THIS PROSPECTUS SUPPLEMENT This document is in two parts. The first part is the prospectus supplement, including the documents incorporated by reference,which describes the specific terms of this offering. The second part, the accompanying prospectus, including the documentsincorporated by reference, provides more general information, some of which may not be applicable to this offering of our commonstock. Generally, when we refer to this prospectus supplement, we are referring to both parts combined. Before you invest, you shouldcarefully read this prospectus supplement, the accompanying prospectus, all information incorporated by reference herein and therein,as well as the additional information described under “Where You Can Find More Information” and “Incorporation of CertainInformation by Reference” in this prospectus supplement. These documents contain information you should consider when makingyour investment decision. This prospectus supplement may add, update or change information contained in the accompanyingprospectus. To the extent that any statement in this prospectus supplement is incons