San Diego, California--(Newsfile Corp. - October 22, 2026) - Thiogenesis Therapeutics, Corp. (TSXV: TTI) (OTCQB: TTIPF) ("Thiogenesis" or the "Company") today announced that the U.S. Food and Drug Administration ("FDA") has cleared its Investigational New Drug ("IND") application for TTI-0102 in nephropathic cystinosis. On October 16, 2026, the FDA issued a "Study May Proceed" letter for IND 184780. The IND is now in effect and supports the investigator-initiated study announced on February 2, 2026.

The study, TTI-CYST-001, will be conducted at Emory University School of Medicine and Children's Healthcare of Atlanta under Dr. Larry Greenbaum, whose site previously participated in the development of delayed-release cysteamine for cystinosis. It is a single-site, open-label pilot in approximately six adults who will switch from their standard cysteamine therapy to once-daily TTI-0102 for seven days. Safety and tolerability are the primary objectives and pharmacokinetics are secondary. White blood cell (WBC) cystine will be evaluated across 24 hours as an exploratory endpoint, using the established surrogate biomarker as the measure of cystine control.

In its letter, the FDA provided comments on the protocol, and the Company will incorporate them into a revised protocol, including additional safety and pharmacology assessments, before submission to the FDA and the institutional review board. Assuming timely study initiation, the Company anticipates topline data in the first quarter of 2027. Subject to results, the data are intended to inform dose selection and longer-term safety evaluation ahead of a registrational trial, which the Company plans to design in agreement with the FDA under the 505(b)(2) regulatory pathway.

"This clearance allows us to move TTI-0102 into patients with cystinosis for the first time," said Dr. Patrice Rioux, Chief Executive Officer of Thiogenesis. "Patients live every day with the dosing frequency, pill burden and side effects of current therapy, and TTI-0102 was designed with that burden in mind. We appreciate the FDA's review and are grateful to Dr. Greenbaum and his team."

"The burden of frequent dosing remains a daily reality for patients with cystinosis and their families. We are pleased to work with Thiogenesis to evaluate the safety and pharmacokinetics of a once-daily powder and explore whether it can maintain cystine control over 24 hours," said Dr. Larry Greenbaum, Professor of Pediatrics at Emory University School of Medicine and principal investigator.

About Nephropathic Cystinosis

Nephropathic cystinosis is a rare, life-threatening genetic disorder in which the amino acid cystine accumulates inside lysosomes, leading to kidney failure in childhood and multi-organ damage. Cysteamine is the standard of care. There are just over 600 diagnosed patients in the United States and an estimated addressable market of $360 million.

About TTI-0102

TTI-0102 is a cysteamine-pantetheine mixed disulfide prodrug, converted in the gastrointestinal tract into two molecules of cysteamine and one of pantothenic acid (vitamin B5). It is a water-soluble powder designed for once-daily oral dosing, with the potential to eliminate the need to swallow capsules. TTI-0102 has completed a Phase 2 trial in MELAS, has an IND-cleared Phase 2a trial in Leigh syndrome with initiation planned for the fourth quarter of 2026, and is in clinical development for cystinosis.

About Thiogenesis Therapeutics

Thiogenesis Therapeutics, Corp. (TSXV: TTI) (OTCQB: TTIPF) is a clinical-stage biopharmaceutical company with operations based in San Diego, CA. The Company is publicly traded on the TSX Venture Exchange and in the U.S. on the OTCQB. Thiogenesis is developing sulfur-containing prodrugs that act as precursors to previously approved thiol-active compounds, with the potential to treat serious pediatric diseases with unmet medical needs.

Forward-Looking Statements

This news release contains forward-looking statements and forward-looking information within the meaning of applicable Canadian securities laws, including statements regarding the status of the Company's IND for TTI-0102, the planned revision of the protocol for TTI-CYST-001 in response to FDA comments, the timing of study initiation and topline data, the use of study data to inform further development, including a registrational trial under the FDA's 505(b)(2) pathway, and the Company's estimate of the addressable market for nephropathic cystinosis. These statements are based on assumptions the Company believes are reasonable as of the date hereof, including that the IND remains in effect, that the protocol revisions can be implemented without material delay, that institutional review board approval and site activation are obtained on the anticipated timeline, that eligible patients can be enrolled in this ultra-rare population, and that the Company can obtain financing on acceptable terms. Actual results may differ materially due to risks including regulatory actions; the FDA's expectation that, before a registrational trial, the Company establish an optimal dose range, generate sufficient clinical and nonclinical safety data to support chronic administration, and reach agreement with the FDA on an adequate and well-controlled trial design, which may require additional studies, time and expense; delays in study start-up or enrollment; the fact that the study is conducted by an independent investigator and institution; the small size, open-label single-arm design and short treatment duration of the study, the results of which may not be predictive of larger or longer trials; the fact that no cystinosis patient data have yet been generated for TTI-0102; availability of financing; and other risks described in the Company's public filings available on SEDAR+ at www.sedarplus.ca. Readers are cautioned not to place undue reliance on forward-looking statements, which speak only as of the date hereof. The Company does not undertake any obligation to update them except as required by applicable law.

Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) nor the OTC Markets Group Inc. (OTCQB: OTCM) accepts responsibility for the adequacy or accuracy of this news release.

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Source: Thiogenesis Therapeutics, Corp.