Mr. Brook Riggins reports

THIOGENESIS REPORTS RESULTS OF 2026 ANNUAL AND SPECIAL MEETING OF SHAREHOLDERS AND PROVIDES CORPORATE UPDATE

Thiogenesis Therapeutics Corp. has released the results of its annual and special meeting of shareholders held on Sept. 8, 2026, and provided a corporate update highlighting recent clinical, regulatory and financial milestones.

Meeting results

All items of business put before shareholders at the meeting were approved by the requisite majority of votes cast.

Shareholders elected the following directors to serve until the next annual meeting or until their successors are elected or appointed: Dr. Christopher Starr (chair), Kim Tsuchimoto (audit committee chair), Hogan Mullally, Dr. Gilad Aharon (co-founder and portfolio manager of Rosalind Advisors Inc.), Dr. Patrice Rioux and Brook Riggins. MNP LLP was also reappointed as the company's auditor until the next annual meeting or until a successor is appointed.

A majority of the disinterested shareholders also approved an amendment to the company's 2024 omnibus equity incentive plan.

Pipeline update

Nephropathic cystinosis

Nephropathic cystinosis is a rare genetic disease that prevents the body from properly clearing a toxic amino acid, cystine, out of cells. Left inadequately treated, cystine buildup progressively damages the kidneys and other organs, often leading to kidney failure in childhood. The current standard of care, Procysbi, requires patients to swallow, depending on body weight, between 16 and 28 capsules a day, twice daily, on a strict fasting schedule, a pill burden and rigid routine that becomes increasingly difficult to sustain over a lifetime of therapy, with lapses in adherence allowing toxic cystine buildup to resume and cause further organ damage.

TTI-0102 is designed to replace that regimen with the potential for a once-daily powder, available in different strengths, so dosing can be tailored to each patient's weight, eliminating pills entirely while continuing to clear cystine from cells.

The company plans to initiate an investigator-initiated study of TTI-0102 in patients with nephropathic cystinosis in the fourth quarter of 2026, in collaboration with Dr. Larry Greenbaum at Emory University. The study will enroll approximately six adult patients already on standard cysteamine therapy, who will switch to once-daily TTI-0102 for a short treatment period before returning to their regular medication. The primary goal is to confirm that a single daily dose of TTI-0102 can keep cystine levels suppressed over a full 24-hour period, the standard needed to potentially reduce dosing frequency from the current multiple-times-per-day regimen. Top-line data from the study are anticipated in the first quarter of 2027.

Leigh syndrome

Leigh syndrome is a rare, severe mitochondrial disease that typically appears in infancy or early childhood, progressively impairing the body's ability to produce cellular energy. There are currently no approved treatments, and care is limited to managing symptoms. TTI-0102 is designed to boost the body's natural antioxidant defences and reduce the cellular stress associated with the disease.

The company plans to initiate its phase 2a clinical trial of TTI-0102 in Leigh syndrome in the fourth quarter of 2026, in collaboration with a leading U.S. children's hospital, under an active U.S. Food and Drug Administration investigational new drug application. The randomized, placebo-controlled trial will enroll approximately nine adolescent and adult patients, two-thirds of whom will receive TTI-0102 daily for a 12-week treatment period. The study will measure changes in biomarkers of oxidative stress and cellular energy production, including glutathione, alongside patient-reported measures of fatigue and daily functioning. Top-line data are anticipated in the second quarter of 2027.

Corporate highlights:

• July 13, 2026: The U.S. FDA granted rare pediatric disease (RPD) designation to TTI-0102 for the treatment of Leigh syndrome. The designation provides the potential, upon approval of a future new drug application, to receive a priority review voucher, and further supports the company's phase 2a clinical program in Leigh syndrome.
• June 1, 2026: Thiogenesis closed a non-brokered private placement, issuing 18,143,700 common shares at 50 cents per share for gross proceeds of $9,071,850, to support continued clinical development of TTI-0102 across the company's pipeline and general working capital.
• Feb. 2, 2026: Thiogenesis announced an investigator-initiated study collaboration with Dr. Greenbaum at Emory University, evaluating TTI-0102 in patients with nephropathic cystinosis to further characterize once-daily dosing, tolerability and white-blood-cell cystine control.
• Jan. 23, 2026: Interim data from the company's phase 2 (European Union) MELAS study of TTI-0102 were presented at Mitocon 2026. Results demonstrated that once-daily, weight-based dosing could achieve sustained 24-hour cysteamine exposure, and, in patients who achieved appropriate weight-adjusted exposure, treatment was associated with improvements in patient-reported fatigue and pharmacodynamic biomarker changes consistent with reduced oxidative stress and improved cellular energy metabolism.

"We are entering a pivotal stretch for Thiogenesis," said Dr. Patrice Rioux, chief executive officer of Thiogenesis. "With new clinical studies set to begin this quarter in both nephropathic cystinosis and Leigh syndrome and top-line data expected across both programs in the first half of 2027, shareholders can look forward to a series of meaningful catalysts over the coming months. Together with the FDA's rare pediatric disease designation and our strengthened balance sheet following the June financing, we believe Thiogenesis is well positioned to advance TTI-0102 across multiple serious pediatric diseases, each representing significant unmet medical need."

The company also announces that, pursuant to the terms of the company's omnibus equity incentive plan and in accordance with the policies of the TSX Venture Exchange, the company's board of directors approved a grant of 200,000 common share purchase options to a director of the company, exercisable at 50 cents per share until Sept. 17, 2031. The options vest in four equal instalments every six months commencing March 17, 2027.

About Thiogenesis Therapeutics Corp.

Thiogenesis is a clinical-stage biopharmaceutical company with operations based in San Diego, Calif. The company is publicly traded on the TSX Venture Exchange and in the United States on the OTCQB. Thiogenesis is developing sulphur-containing pro-drugs that act as precursors to previously approved thiol-active compounds, with the potential to treat serious pediatric diseases with unmet medical needs. Thiogenesis's lead product candidate, TTI-0102, has completed a phase 2 clinical trial in mitochondrial encephalopathy, lactic acidosis and stroke-like episodes (MELAS), has an IND-cleared phase 2a clinical trial in Leigh syndrome, and is advancing an investigator-initiated study in nephropathic cystinosis.

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