Protara Therapeutics Inc美股招股说明书(2025-12-04版)

Filed Pursuant to Rule 424(b)(5)Registration No. 333-275290 The information in this preliminary prospectus supplement is not complete and may be changed. This preliminary prospectussupplement and the accompanying prospectus are not an offer to sell these securities and are not soliciting an offer to buy these SUBJECT TO COMPLETION, DATED DECEMBER 4, 2025 PROSPECTUS SUPPLEMENT(To Prospectus dated November 14, 2023) We are offeringshares of our common stock, par value $0.001 per share, in this offering and, in lieu of commonstock to certain investors that so choose, pre-funded warrants to purchaseshares of common stock, pursuant to thisprospectus supplement and the accompanying prospectus. The purchase price of each pre-funded warrant equals the price per share at Our common stock is listed on The Nasdaq Global Market, or Nasdaq, under the symbol “TARA”. On December 3, 2025, thelast reported sale price of our common stock was $6.80 per share. There is no established public trading market for the pre-fundedwarrants, and we do not expect a market to develop. In addition, we do not intend to apply for a listing of the pre-funded warrants on Investing in our securities involves a high degree of risk. You should review carefully the risks and uncertaintiesdescribed under the heading “Risk Factors” on page S-5 of this prospectus supplement and under similar headings in the other We are a “smaller reporting company” under applicable federal securities laws, and, as such, we are subject toreduced public company reporting requirements. See “Prospectus Supplement Summary—Implications of Being a SmallerReporting Company.” NEITHER THE SECURITIES AND EXCHANGE COMMISSION NOR ANY STATE SECURITIES COMMISSIONHASAPPROVED OR DISAPPROVED OF THESE SECURITIES OR DETERMINED IF THIS PROSPECTUSSUPPLEMENT OR THE ACCOMPANYING PROSPECTUS IS TRUTHFUL OR COMPLETE. ANY REPRESENTATION (1)See the section titled “Underwriting” for additional information regarding compensation payable to the underwriters. We have granted the underwriters the option for a period of up to 30 days from the date of this prospectus supplement topurchase up to an additionalshares of common stock from us at the public offering price, less the underwriting discount. Prospectus Supplement ABOUT THIS PROSPECTUS SUPPLEMENT This document is in two parts. The first part is this prospectus supplement, which describes the terms of this offering ofcommon stock and pre-funded warrants and also adds to and updates information contained in the accompanying prospectus and thedocuments incorporated by reference into this prospectus supplement and the accompanying prospectus. The second part, theaccompanying prospectus, provides more general information about our common stock and pre-funded warrants. To the extent theinformation contained in this prospectus supplement differs or varies from the information contained in the accompanying prospectusor the documents incorporated by reference, you should rely on the information in this prospectus supplement. Any statements made inthis prospectus supplement or the accompanying prospectus concerning the provisions of legal documents are not necessarily complete You should rely only on the information contained or incorporated by reference in this prospectus supplement and theaccompanying prospectus and in any free writing prospectus we authorize that supplements this prospectus supplement. We have not,and the underwriters have not, authorized any other person to provide you with different information or make any representations otherthan those contained or incorporated by reference in this prospectus supplement. If anyone other than us provides you with different orinconsistent information, you should not rely on it. We take no responsibility for, and can provide no assurance as to the reliability of,any other information that others may give you. We are not, and the underwriters are not, making an offer to sell these securities in any Unless otherwise stated, all references in this prospectus supplement to “we,” “us,” “our,” “Protara,” the “Company” andsimilar designations refer to Protara Therapeutics, Inc. This prospectus supplement contains references to trademarks belonging toother entities. Solely for convenience, trademarks and trade names referred to in this prospectus supplement, including logos, artworkand other visual displays, may appear without the ® or ™ symbols, but such references are not intended to indicate, in any way, thatthe applicable licensor will not assert, to the fullest extent under applicable law, its rights to these trademarks and trade names. We do PROSPECTUS SUPPLEMENT SUMMARY This summary highlights information included or incorporated by reference in this prospectus supplement and theaccompanying prospectus. It does not contain all the information that may be important to you or that you may wish to considerbefore making an investment decision. You should read carefully the entire prospect