LTI-03

AUSTIN, Texas, April 30, 2026 (GLOBE NEWSWIRE) -- Rein Therapeutics, Inc. ("Rein" or the "Company") (NASDAQ: RNTX), a clinical-stage biopharmaceutical company advancing a novel pipeline of first-in-class medicines for orphan pulmonary and fibrosis indications, today announced the pricing of its underwritten public offering of fifty million shares of its common stock at a public offering price of $1.00 per share for aggregate gross proceeds of $50 million, prior to deducting underwriting discounts and commissions and other offering expenses. In addition, the Company has granted the underwriters a 45-day option to purchase up to an additional 7.5M shares of common stock at the public offering price per share, less the underwriting discounts and commissions, to cover over-allotments, if any. The offering is expected to close on or about May 4, 2026, subject to the satisfaction of customary closing conditions. The offering consisted entirely of common stock with no warrants. Konik Capital Partners, LLC, a division of T.R. Winston & Company, LLC, is acting as the sole book-running manager for the offering. Rein intends to use the net proceeds from the offering to fully fund its ongoing Phase 2 clinical trial of LTI-03 in idiopathic pulmonary fibrosis (IPF) through completion and for working capital and general corporate purposes. Based on its current operating plan, the Company believes the net proceeds from this offering, together with its existing cash and cash equivalents, will be sufficient to fund its operations into 2028. The securities described above are being offered and sold pursuant to a registration statement on Form S-1 (File No. 333-295390), including a prospectus, filed with the U.S. Securities and Exchange Commission (the "SEC"), which was declared effective by the SEC on April 30, 2026. The offering is being made only by means of a prospectus that forms part of the effective registration statement. A final prospectus relating to the offering will be filed with the SEC and will be available on the SEC’s website at . Copies of the final prospectus may be obtained, when available, from Konik Capital Partners, LLC, a division of T.R. Winston & Company, LLC, at 7 World Trade Center, 46th Floor, New York, NY 10007, Attention: Capital Markets Team, Email: capmarkets@konikcapitalpartners.com. This press release shall not constitute an offer to sell or the solicitation of an offer to buy any of the securities described herein, nor shall there be any sale of these securities in any state or jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state or jurisdiction. About Rein Therapeutics Rein Therapeutics is a clinical-stage biopharmaceutical company advancing a novel pipeline of first-in-class therapies to address significant unmet medical needs in orphan pulmonary and fibrosis indications. Rein’s lead product candidate, LTI-03, is a novel, synthetic peptide with a dual mechanism targeting alveolar epithelial cell survival as well as inhibition of profibrotic signaling. LTI-03 has received Orphan Drug Designation in the U.S. Rein’s second product candidate, LTI-01, is a proenzyme that has completed Phase 1b and Phase 2a clinical trials for the treatment of loculated pleural effusions. LTI-01 has received Orphan Drug Designation in the U.S. and E.U. and Fast Track Designation in the U.S. Cautionary Note Regarding Forward-Looking Statements This press release may contain forward-looking statements of Rein Therapeutics, Inc. (“Rein”, the “Company”, “we”, “our” or “us”) within the meaning of the Private Securities Litigation Reform Act of 1995, including statements with respect to expectations for the Company’s LTI-03 and LTI-01 product candidates and the closing of the offering. We use words such as “anticipate,” “believe,” “estimate,” “expect,” “hope,” “intend,” “may,” “plan,” “predict,” “project,” “target,” “potential,” “would,” “can,” “could,” “should,” “continue,” and other words and terms of similar meaning to help identify forward-looking statements, although not all forward-looking statements contain these identifying words. Actual results may differ materially from those indicated by such forward-looking statements as a result of various important factors, including: (i) the risk that the offering may not be completed, (ii) the risk that the net proceeds of the offering may not be sufficient to fund the Company’s operations into 2028, and (iii) those other risks disclosed in the “Risk Factors” section of the Company’s Annual Report on Form 10-K for the year ended December 31, 2025 filed with the SEC on March 26, 2026, and in subsequent filings that the Company makes with the SEC. These forward-looking statements should not be relied upon as representing the Company’s views as of any date after the date of this press release, and the Company expressly disclaims any obligation to update any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law. Rein Therapeutics Investor Relations & Media Contact: Investor Relations IR@ReinTx.com

Patient enrollment accelerates across expanding number of clinical trial sites in multiple countries 8 patients enrolled, with additional patients expected in the near term Enrollment initiated in March 2026, with patients being added on a regular basis Clinical trial sites active in the United States, Australia, and Poland, with additional countries expected to open in the near term AUSTIN, Texas, April 29, 2026 (GLOBE NEWSWIRE) -- Rein Therapeutics ("Rein") (NASDAQ: RNTX), a biopharmaceutical company advancing a novel pipeline of first-in-class medicines to address significant unmet medical needs in orphan pulmonary and fibrosis indications, today provided an update on its ongoing Phase 2 RENEW clinical trial evaluating LTI-03 for the treatment of idiopathic pulmonary fibrosis (IPF). The Company has enrolled 8 patients in its RENEW trial to date, with 2 additional patients expected to be enrolled this week. Enrollment in the study began in March 2026, and the Company continues to add patients on a regular basis. Rein also continues to make progress on expanding its global clinical trial footprint. Clinical trial sites are currently active in the United States, Australia, and Poland, with additional countries – including the United Kingdom and Germany – expected to open in the near term. The Company plans to continue activating more new sites to support ongoing enrollment Brian Windsor, Ph.D., Chief Executive Officer of Rein Therapeutics, commented, “We are pleased with the progress of our Phase 2 RENEW trial, including our ongoing patient enrollment and the expansion of clinical trial sites across multiple geographies. We believe this continued execution reflects the successful efforts of our clinical teams and investigators, and we remain focused on advancing LTI-03 through development.” About the RENEW Phase 2 Trial Rein’s RENEW trial is a randomized, placebo-controlled Phase 2 clinical study designed to evaluate the safety, tolerability, and efficacy of LTI-03 in patients with idiopathic pulmonary fibrosis. The study is expected to enroll approximately 120 patients, who will be randomized to receive one of two dose levels of LTI-03 or placebo. The major efficacy endpoint is the change from baseline in forced vital capacity (FVC), a key measure of lung function. About LTI-03 LTI-03 is a first-in-class, inhaled peptide therapy derived from Caveolin-1 biology, a key regulator of fibrotic signaling. The drug is designed to inhibit lung scarring while preserving alveolar progenitor cells that are critical for tissue repair and regeneration. Early data suggests that LTI-03 may represent a dual-acting approach: slowing fibrosis and promoting lung healing. About Rein Therapeutics Rein Therapeutics is a clinical-stage biopharmaceutical company advancing a novel pipeline of first-in-class therapies to address significant unmet medical needs in orphan pulmonary and fibrosis indications. Rein's lead product candidate, LTI-03, is a novel, synthetic peptide with a dual mechanism targeting alveolar epithelial cell survival as well as inhibition of profibrotic signaling. LTI-03 has received Orphan Drug Designation in the U.S. Rein's second product candidate, LTI-01, is a proenzyme that has completed Phase 1b and Phase 2a clinical trials for the treatment of loculated pleural effusions. LTI-01 has received Orphan Drug Designation in the U.S. and E.U. and Fast Track Designation in the U.S. Forward-Looking Statements This press release may contain forward-looking statements of Rein Therapeutics, Inc. ("Rein", the "Company", "we", "our" or "us") within the meaning of the Private Securities Litigation Reform Act of 1995, including statements with respect to expectations for the Company’s LTI-03 product candidate. We use words such as "anticipate," "believe," "estimate," "expect," "hope," "intend," "may," "plan," "predict," "project," "target," "potential," "would," "can," "could," "should," "continue," and other words and terms of similar meaning to help identify forward-looking statements, although not all forward-looking statements contain these identifying words. Actual results may differ materially from those indicated by such forward-looking statements as a result of various important factors, including: (i) the risk that the Company may not be able to successfully continue its Phase 2 clinical trials of LTI-03; (ii) the data derived from our Phase 2 clinical trials of LTI-03 may not support or validate our expectations concerning the potential benefits of LTI-03; (iii) success in early phases of pre-clinical and clinical trials do not ensure later clinical trials will be successful; (iv) the risk that the Company may not be able to obtain additional working capital with which to complete the planned clinical trials of LTI-03; and (v) those other risks disclosed in the "Risk Factors" section of the Company's Annual Report on Form 10-K for the year ended December 31, 2025, which is on the United States Securities and Exchange Commission (the "SEC") and in subsequent filings that the Company files with the SEC. These forward-looking statements should not be relied upon as representing the Company's view as of any date after the date of this press release, and we expressly disclaim any obligation to update any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law. Rein Investor Relations & Media Contact: Investor Relations IR@ReinTx.com