Rein Therapeutics, Inc. 10-Q

Item 1. Legal Proceedings. We are not currently a party to any material legal proceedings. From time to time, we may be subject to various legal proceedings and claims that arise in the ordinary course of our business activities. Regardless of the outcome, litigation can have a material adverse impact on us because of defense and settlement, costs, diversion of management resources, and other factors. Item 1A. Ri sk Factors. We require substantial additional capital to finance our operations. If we are unable to raise such capital when needed, or on acceptable terms, we may be forced to delay, reduce and/or eliminate one or more of our clinical and research and development programs, future commercialization efforts or other operations. As of September 30, 2025, we had cash and cash equivalents of $4.0 million. Based on our current operating plan, we believe that our existing cash and cash equivalents as of September 30, 2025, together with the proceeds received by us pursuant to the PPA in October 2025, will be sufficient to enable us to fund our operating expenses and capital expenditure requirements only into December 2025. As a result, we will need additional capital to fund our operations, which we may obtain from additional equity or debt financings, strategic collaborations, licensing arrangements or other sources. If we are unable to obtain sufficient funding on terms acceptable to us, on a timely basis or at all, we may be forced to delay, reduce or eliminate some or all of our research and development programs, product portfolio expansion or future commercialization efforts, which could adversely affect our business prospects, or we may be unable to continue operations. We believe that our working capital as of September 30, 2025, together with the proceeds received by us pursuant to the PPA in October 2025, lack of revenue and recurring net losses raise substantial doubt about our ability to continue as a going concern. For a discussion of our other risk factors, see “Part I, Item 1A-Risk Factors” in our Annual Report on Form 10-K for the year ended December 31, 2024 filed with the SEC on April 7, 2025. You should carefully consider the risks included in our Annual Report on Form 10-K, together with all of the other information in this Quarterly Report on Form 10-Q, including our unaudited condensed consolidated financial statements and the related notes included elsewhere in this Quarterly Report on Form 10-Q. The occurrence of any single risk or any combination of risks could materially and adversely affect our business, financial condition, results of operations, cash flows and the trading price of our common stock. Item 2. Unreg istered Sales of Equity Securities and Use of Proceeds During the three months ended September 30, 2025, we sold 1,880,872 shares of our common stock to Yorkville, in satisfaction of an aggregate of $2.0 million of principal and accrued interest owed by us to Yorkville under our Pre-Paid Advance Agreement dated July 29, 2025. All shares of common stock issued and sold to Yorkville were issued pursuant to Section 4(a)(2) of the Securities Act, as transactions not involving a public offering. Item 3. Defau lts Upon Senior Securities Not applicable. Item 4. Mi ne Safety Disclosures Not applicable. Item 5. Oth er Information During the nine months ended September 30, 2025, no director or officer of the Company adopted or terminated a Rule 10b5-1 trading arrangement or non-Rule 10b5-1 trading arrangement, as each term is defined in Item 408(a) of Regulation S-K. 37 Item 6. E xhibits. The exhibits listed on the Exhibit Index immediately preceding such exhibits, which is incorporated herein by reference, are filed or furnished as part of this Quarterly Report on Form 10-Q. Exhibit Number Description 3.1 Restated Certificate of Incorporation of the Registrant, as amended (incorporated by reference to Exhibit 3.1 of the Company’s Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission on August 11, 2021). 3.2 Certificate of Amendment of Restated Certificate of Incorporation of the Registrant, dated as of November 10, 2022 (incorporated by reference to Exhibit 3.1 of the Company’s Current Report on Form 8-K filed with the Securities and Exchange Commission on November 10, 2022). 3.3 Certificate of Amendment of Restated Certificate of Incorporation of the Registrant, dated February 28, 2024 (incorporated by reference to Exhibit 3.3 of the Company’s Annual Report on Form 10-K filed with the Securities and Exchange Commission on April 15, 2024). 3.4 Certificate of Amendment to Restated Certificate of Incorporation (incorporated by reference to Exhibit 3.1 to the Company’s Current Report on Form 8-K filed with the Securities and Exchange Commission on January 10, 2025). 3.5 Amended and Restated Bylaws, as amended. 10.1 Pre-Paid Advance Agreement, dated as of July 29, 2025, between the Registrant and YA II PN, Ltd. (Incorporated by reference from Registrant’s Current Report on Form 8-K filed on July 30, 2025) 10.2 Standby Equity Purchase Agreement, dated as of July 29, 2025, between the Registrant and YA II PN, Ltd. (Incorporated by reference from Registrant’s Current Report on Form 8-K filed on July 30, 2025) 31.1 Certification of Principal Executive Officer Pursuant to Rules 13a-14(a) and 15d-14(a) under the Securities Exchange Act of 1934, as Adopted Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002. 31.2 Certification of Principal Financial Officer Pursuant to Rules 13a-14(a) and 15d-14(a) under the Securities Exchange Act of 1934, as Adopted Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002. 32.1 Certification of Principal Executive Officer Pursuant to 18 U.S.C. Section 1350, as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002. 32.2 Certification of Principal Financial Officer Pursuant to 18 U.S.C. Section 1350, as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002. 101.INS Inline XBRL Instance Document – the instance document does not appear in the Interactive Data File because XBRL tags are embedded within the Inline XBRL document. 101.SCH Inline XBRL Taxonomy Extension Schema With Embedded Linkbase Documents 104 Cover Page Interactive Data File (embedded within the Inline XBRL document) * Indicates management contract or compensatory plan. + In accordance with Item 601(b)(10)(iv) of Regulation S-K, certain information (indicated by “[**]”) has been excluded from this exhibit because it is both not material and private or confidential. A copy of the omitted portion will be furnished to the SEC upon request. # Certain schedules and similar attachments have been omitted pursuant to Item 601(a)(5) of Regulation S-K. The registrant undertakes to furnish supplemental copies of any of the omitted schedules upon request by the SEC. 38 SIGNA TURES Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized. Rein Therapeutics, Inc. Date: November 14, 2025 By: /s/ Brian Windsor, Ph.D. Brian Windsor, Ph.D. President and Chief Executive Officer (Principal Executive Officer) Date: November 14, 2025 By: /s/ Timothy M. Cunningham Timothy M. Cunningham Interim Chief Financial Officer (Principal Financial Officer) 39