Protara Therapeutics Inc美国招股说明书（2026年5月28日版）

PROSPECTUS SUPPLEMENT(To Prospectus dated May 22, 2026) $100,000,000 Common Stock We have entered into a sales agreement with TD Securities (USA) LLC, or TD Cowen, dated May 13, 2026, or the SalesAgreement, relating to the sale of shares of our common stock, par value $0.001 per share, offered by this prospectus supplement andthe accompanying prospectus. In accordance with the terms of the Sales Agreement, we may offer and sell shares of our common Our common stock is listed on The Nasdaq Global Market, or Nasdaq, under the symbol “TARA.” On May 11, 2026, the lastreported sale price of our common stock was $5.27 per share. Sales of our common stock, if any, under this prospectus supplement and the accompanying prospectus may be made in salesdeemed to be in negotiated transactions, including block trades or block sales, or by any method permitted by law to be deemed an “atthe market offering” as defined in Rule 415 promulgated under the Securities Act of 1933, as amended, or the Securities Act, includingwithout limitation sales made through Nasdaq or on any other trading market for our common stock, or by any other method permittedby law. TD Cowen is not required to sell any specific amount of our common stock, but will act as our sales agent using commercially The compensation to TD Cowen for sales of common stock sold pursuant to the Sales Agreement will be an amount up to3.0% of the gross proceeds of any shares of common stock sold thereunder. See “Plan of Distribution” beginning on page S-12 of thisprospectus supplement for additional information regarding the compensation to be paid to TD Cowen. In connection with the sale ofthe common stock on our behalf, TD Cowen may be deemed to be an “underwriter” within the meaning of the Securities Act, and the Investing in our common stock involves a high degree of risk. Before making an investment decision, please read theinformation under the heading “Risk Factors” beginning on page S-6 of this prospectus supplement and page 7 of the NEITHER THE SECURITIES AND EXCHANGE COMMISSION NOR ANY STATE SECURITIES COMMISSIONHASAPPROVED OR DISAPPROVED OF THESE SECURITIES OR DETERMINED IF THIS PROSPECTUSSUPPLEMENT IS TRUTHFUL OR COMPLETE. ANY REPRESENTATION TO THE CONTRARY IS A CRIMINAL The date of this prospectus supplement is May 22, 2026. ABOUT THIS PROSPECTUS SUPPLEMENT This prospectus supplement is a part of a registration statement on Form S-3 that we filed with the Securities and ExchangeCommission, or SEC, utilizing a “shelf” registration process. Under this shelf registration process, we may sell any combination of thesecurities described in the accompanying prospectus in one or more offerings up to a total aggregate offering price of $300,000,000. This document is in two parts. The first part is this prospectus supplement, which describes the terms of this offering ofcommon stock and also adds to and updates information contained in the accompanying prospectus and the documents incorporated byreference into this prospectus supplement and the accompanying prospectus. The second part, the accompanying prospectus, providesmore general information about our common stock. To the extent the information contained in this prospectus supplement differs orvaries from the information contained in the accompanying prospectus or the documents incorporated by reference, you should rely onthe information in this prospectus supplement. Any statements made in this prospectus supplement or the accompanying prospectus 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, including the information incorporated byreference into this prospectus supplement, contains references to trademarks belonging to other entities. Solely for convenience,trademarks and trade names referred to in this prospectus supplement, including logos, artwork and other visual displays, may appearwithout the ® or ™ symbols, but such references are not intended to indicate, in any way, that the applicable licensor will not assert, to PROSPECTUS SUPPLEMENT SUMMARY This follo