IND authorization paves the way for initiation of GT-02287 Phase 2 clinical development in the U.S., expected during 3Q26

FDA’s decision follows positive Phase 1 results for GT-02287 in both healthy volunteers and people with Parkinson’s disease demonstrating both biomarker and clinical evidence of activity with favorable safety and tolerability

GT-02287 is the first allosteric modulator developed from Gain’s Magellan™ AI drug discovery platform to receive IND clearance

BETHESDA, Md., June 29, 2026 (GLOBE NEWSWIRE) -- Gain Therapeutics, Inc. (NASDAQ:GANX) ("Gain", or the "Company"), a clinical-stage biotechnology company leading the discovery and development of the next generation of allosteric small molecule therapies, today announced that the U.S. Food and Drug Administration (FDA) has authorized the Company’s Investigational New Drug (IND) application for GT-02287. The FDA’s decision will allow initiation of the Company’s Phase 2 clinical development of GT-02287 in Parkinson’s disease with or without a GBA1 mutation in the U.S.

Both the Phase 1a and Phase 1b studies of GT-02287 were conducted in Australia. The sites in Australia are expected to also participate in the Phase 2 study along with new sites in the U.S. and select European centers.

"We appreciate the FDA’s guidance throughout the IND review process and look forward to initiating our Phase 2 study, which is anticipated to occur during 3Q26," said Gene Mack, President and CEO of Gain Therapeutics. "In clinical studies to date, GT-02287 demonstrated target engagement with favorable safety and tolerability. Additionally, recent feedback from trial participants across different clinical sites included anecdotal reports of improvements in smell and taste, balance or gait, and sleep. The FDA’s decision is a significant milestone for Gain and we believe it validates the extensive preclinical and clinical work supporting further development of GT-02287. We believe GT-02287 represents the next generation of differentiated therapeutics designed to address the underlying biology of Parkinson’s disease and move beyond symptomatic relief to create a new backbone of treatment that can slow or stop disease progression," concluded Mr. Mack.

The Company believes its Phase 1b extension data support the continued development of GT-02287 in Parkinson's disease, with continued safety and tolerability observed through five months of treatment. All 16 participants who entered the ongoing Phase 1b extension study remained on study at Day 150, and an independent Data Monitoring Committee recommended the study continue without modification. Biomarker analyses showed sustained target engagement, including an average 81% reduction in cerebrospinal fluid (CSF) glucosylsphingosine (GluSph) after 90 days in participants with elevated baseline levels, along with reductions in DOPA decarboxylase (DDC).

Clinical findings were consistent with the biomarker data, with participants who had elevated baseline CSF GluSph demonstrating greater improvement in MDS-UPDRS Part II and III scores than those with low baseline GluSph at Day 150, while scores remained stable across the overall study population. Participants also reported improvements in motor and non-motor symptoms, including smell, gait, and sleep, which the Company anticipates will be further evaluated using objective measures in the planned Phase 2 study.

The planned Phase 2a study of oral GT-02287 in treated and untreated participants with early Parkinson’s disease is expected to enroll participants across sites in the United States, Australia, and Europe. The Company expects initiation of the Phase 2a in 3Q26.

Parkinson's disease, the second most common neurodegenerative disease after Alzheimer’s disease, affects more than 1.1 million people in the United States alone, with nearly 90,000 new diagnoses each year. Despite available symptomatic treatments, there are currently no approved therapies that halt or reverse disease progression, leaving a substantial unmet need for innovative treatments that address the underlying biology of Parkinson's disease and improve long-term patient outcomes.

About GT-02287

Gain Therapeutics’ lead drug candidate, GT-02287, is in clinical development for the treatment of Parkinson’s disease (PD) with or without a GBA1 mutation. The orally administered, brain-penetrant small molecule is an allosteric enzyme modulator that restores the function of the lysosomal enzyme glucocerebrosidase (GCase) which becomes misfolded and impaired due to mutations in the GBA1 gene, the most common genetic abnormality associated with PD, or other age-related stress factors.

In preclinical models of PD, GT-02287 restored GCase enzymatic function, reduced endoplasmic reticulum stress, lysosomal and mitochondrial pathology, aggregated α-synuclein, neuroinflammation and neuronal death, as well as plasma neurofilament light chain (NfL) levels, a biomarker of neurodegeneration. In rodent models of both GBA1-PD and idiopathic PD, GT-02287 was shown to rescue deficits in motor function and gait and prevent the development of deficits in complex behaviors such as nesting. Compelling data in these models, demonstrating a disease-modifying effect of GT-02287, suggest that the drug candidate may have the potential to slow or stop the progression of Parkinson’s disease.

Initial results from the Phase 1b clinical trial in people with Parkinson’s disease demonstrated central nervous system target engagement, a reduction to baseline levels in the prespecified endpoint glucosylsphingosine (GluSph), and improvement or stabilization in MDS-UPDRS scores. Additionally, participants with elevated levels of CSF GluSph also exhibited elevated levels of DOPA decarboxylase (DDC), which decreased following treatment with GT-02287.

Gain’s lead program in Parkinson’s disease has been awarded funding support early in its development from The Michael J. Fox Foundation for Parkinson’s Research (MJFF) and The Silverstein Foundation for Parkinson’s with GBA, as well as from the Eurostars-2 joint program with co-funding from the European Union Horizon 2020 research and Innosuisse – Swiss Innovation Agency.

About Gain Therapeutics, Inc.

Gain Therapeutics, Inc. is a clinical-stage biotechnology company leading the discovery and development of next generation allosteric therapies. Gain’s lead drug candidate, GT-02287 is currently being evaluated for the treatment of Parkinson’s disease with or without a GBA1 mutation in a Phase 1b clinical trial. GT-02287 has further potential in Gaucher’s disease, dementia with Lewy bodies, and Alzheimer’s disease. Gain has multiple undisclosed preclinical assets targeting lysosomal storage disorders, metabolic diseases, and solid tumors.

Gain’s unique approach enables the discovery of novel, allosteric small molecule modulators that can restore or disrupt protein function. Deploying its highly advanced Magellan™ platform, Gain is accelerating drug discovery and unlocking novel disease-modifying treatments for untreatable or difficult-to-treat disorders including neurodegenerative diseases, rare genetic disorders and oncology.

Forward-Looking Statements

This release contains "forward-looking statements" made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. These statements are typically preceded by words such as "believes," "expects," "anticipates," "intends," "will," "may," "should," or similar expressions. These forward-looking statements reflect management’s current knowledge, assumptions, judgment and expectations regarding future performance or events. Although management believes that the expectations reflected in such statements are reasonable, they give no assurance that such expectations will prove to be correct or that those goals will be achieved, and you should be aware that actual results could differ materially from those contained in the forward-looking statements. Such forward-looking statements include, but are not limited to, statements regarding: the development of the Company’s current or future product candidates including GT-02287; expectations regarding the completion and timing of results from a Phase 1b clinical study for GT-02287, including any extension studies; expectations regarding the timing of patient enrollment for a Phase 1b clinical study for GT-02287, including any extension studies; the timing of any submissions to the FDA or other regulatory bodies and agencies and the timing of any responses from the FDA or other regulatory bodies and agencies; the timing of the commencement of the Phase 2 clinical study for GT-02287; the ability for the Company to enroll patients in its planned Phase 2 clinical study for GT-02287; the Company’s ability to replicate positive results from earlier preclinical studies or clinical trials in current or future clinical trials; and the potential therapeutic and clinical benefits of the Company’s product candidates, including GT-02287. For a further description of the risks and uncertainties that could cause actual results to differ from those expressed in these forward-looking statements, as well as risks relating to the Company’s business in general, please refer to the Company’s Form 10-K for the year ended December 31, 2025, and other filings made with the SEC. All forward-looking statements are expressly qualified in their entirety by this cautionary notice. You are cautioned not to place undue reliance on any forward-looking statements, which speak only as of the date of this release. We have no obligation, and expressly disclaim any obligation, to update, revise or correct any of the forward-looking statements, whether because of new information, future events or otherwise.

Investors:

Gain Therapeutics, Inc.

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