FDA’s written feedback indicates the IND is fileable on data in hand subject to two defined nonclinical additions, supports the nonclinical package for a proposed exploratory study, endorses plasma lyso-Gb3 as the pharmacodynamic readout, agrees that eGFR interpreted over at least two years is reasonable, and confirms manufacturing leverage across the Live-cel platform.

PARK CITY, Utah, August 19, 2026. Glafabra Therapeutics, a preclinical, pre-IND gene therapy company developing Live-cel, a lentivirus-mediated autologous stem-cell gene therapy platform for lysosomal storage disorders, today announced the completion of its INTERACT meeting with the U.S. Food and Drug Administration (FDA) for its lead program, GT-GLA-S03, a cell-based gene therapy for classic Fabry disease. The face-to-face meeting, held on July 16, 2026 with FDA’s CBER Office of Therapeutic Products, produced constructive written feedback that clarifies the steps toward a future Investigational New Drug (IND) application.

The INTERACT (INitial Targeted Engagement for Regulatory Advice on CBER producTs) program provides early, non-binding scientific advice to sponsors developing novel products. FDA declines approximately two-thirds of INTERACT requests, and the face-to-face format is the highest-engagement response available before an IND. For Glafabra, the meeting advanced the Fabry program from an accepted meeting to a completed one, with a defined path toward the clinic.

FDA feedback affirmed core elements of the program

Across the topics discussed, the Agency’s written responses supported several central elements of Glafabra’s approach for a proposed early, exploratory clinical study:

• Nonclinical package. FDA generally agreed that the nonclinical data provided are sufficient to support the proposed exploratory, early-phase clinical study, and indicated the IND is fileable on data in hand subject to two defined additions: an in vitro immortalization assay and integration-site analysis with clonal-dominance assessment.

• Pharmacodynamic biomarker. FDA agreed that plasma lyso-Gb3 is an appropriate pharmacodynamic measure of treatment response in the proposed exploratory study, and recommended prioritizing it over plasma Gb3 using a validated assay. Consistent with that advice, Glafabra treats lyso-Gb3 as a pharmacodynamic readout rather than an efficacy endpoint.

• Trial design. FDA accepted the within-subject change-from-baseline exploratory design as reasonable for an early study intended to characterize response and inform a future pivotal trial.

• Renal and cardiac measures. FDA agreed that estimated glomerular filtration rate (eGFR), interpreted over at least two years, is reasonable, and supported assessment of cardiac imaging and exercise-capacity measures. Glafabra’s intended registrational primary is the biopsy-free eGFR-slope route of FDA’s Fabry guidance.

• Platform leverage. FDA confirmed that chemistry, manufacturing, and controls (CMC) and manufacturing knowledge can be leveraged across the platform’s follow-on programs in Pompe and Gaucher disease, with appropriate justification, each advancing under its own IND.

• A defined path forward. The Agency outlined the next steps, including future Pre-IND and End-of-Phase-1 meetings, at which the registrational endpoint and re-dosing will be addressed.

As with all INTERACT interactions, the feedback is preliminary and non-binding, and the proposed exploratory study is not itself a pivotal trial. Glafabra intends to address the Agency’s recommendations as it prepares its IND and pursues the regulatory pathways available for a serious disease with high unmet need.

Management commentary

“Completing our INTERACT meeting is a defining step for Glafabra,” said Dr. Chris Hopkins, Chief Executive Officer of Glafabra Therapeutics. “We came away with no strong objections to our approach and a much clearer view of what a successful IND will require. The Agency told us the IND is fileable on the data we already hold, subject to two specific nonclinical additions, which turns an open-ended preclinical program into a bounded one. Fabry patients have waited a long time for an alternative to lifelong infusions, and this meeting brings a durable, re-administrable outpatient therapy meaningfully closer to the clinic.”

About Fabry disease and GT-GLA-S03

Fabry disease is a rare, X-linked lysosomal storage disorder caused by deficient activity of the enzyme alpha-galactosidase A, leading to progressive accumulation of the substrate Gb3 and its derivative lyso-Gb3 and to multi-system organ damage. The current standard of care, enzyme replacement therapy, requires lifelong intravenous infusions every two weeks, produces a peak-and-trough enzyme cycle, does not halt long-term organ damage, and provokes anti-drug antibodies in approximately 40 percent of patients. Oral chaperone therapy reaches fewer than half of patients, those carrying an amenable GLA variant.

GT-GLA-S03 is designed to replace that infusion burden with an outpatient procedure that delivers durable, steady-state enzyme expression from the patient’s own gene-modified cells, using a reduced-intensity, non-myeloablative single-agent melphalan conditioning regimen in place of the myeloablative busulfan that restricted predecessor stem-cell gene therapy programs. In the co-founders’ clinical pilot study, four of five patients completed conditioning as a same-day outpatient procedure. Because the approach is autologous and uses no viral capsid, it is re-administrable as expression declines and is not subject to the pre-existing anti-capsid antibody exclusions that render roughly 40 percent of adults ineligible for AAV gene therapy approaches, which are non-repeatable. GT-GLA-S03 is designed to be re-administered on an interval of five or more years rather than delivered once.

Human proof of concept

The Live-cel platform is supported by five-year human proof-of-concept data from an investigator-initiated clinical pilot study (the FACTS trial, NCT02800070) conducted by Glafabra’s scientific co-founders, Dr. Jeffrey Medin and Dr. Ronan Foley, in Canada under Canadian regulatory oversight. Across five patients followed for five years, the study showed a 48 percent reduction in plasma lyso-Gb3 from a no-enzyme-replacement-therapy baseline (p less than 0.0001), polyclonal vector integration with no clonal dominance, and no product-attributable serious adverse events. Results have been published in Nature Communications, Clinical and Translational Medicine, and Molecular Therapy Methods and Clinical Development. This work is proof of concept for the platform and is distinct from any Glafabra-sponsored IND program.

About the Live-cel platform

Live-cel applies a single closed, lentivirus-mediated autologous stem-cell manufacturing process across multiple lysosomal storage disorders, including Fabry (GT-GLA-S03), Pompe (GT-GAA-S04), and Gaucher (GT-GBA1-S05) disease, with the potential to extend to a broad class of enzyme-deficiency disorders. The FDA has granted Orphan Drug Designation to the Fabry program, and applications are pending for the Pompe and Gaucher programs.

About Glafabra Therapeutics

Glafabra Therapeutics is a preclinical, pre-IND gene therapy company developing Live-cel, a lentivirus-mediated autologous stem-cell gene therapy platform for lysosomal storage disorders. The company’s lead program, GT-GLA-S03, is in development for classic Fabry disease, with additional programs for Pompe (GT-GAA-S04) and Gaucher (GT-GBA1-S05) disease built on the same manufacturing process. The platform is supported by five-year human proof-of-concept data from an investigator-initiated study conducted by the company’s scientific co-founders in Canada. Glafabra is targeting IND submission approximately twelve to fifteen months after its GMP manufacturing campaign begins. Learn more at glafabra.com.

Media and Company Contact

Dr. Chris Hopkins

Chief Executive Officer, Glafabra Therapeutics

chris@glafabra.com  |  +1 801 631 9114  |  glafabra.com

Forward-Looking Statements

This press release contains forward-looking statements, including statements regarding Glafabra’s development plans, the anticipated timing of a future IND filing, the design and objectives of planned clinical studies, and the potential of the Live-cel platform. Forward-looking statements are based on management’s current expectations and are subject to risks and uncertainties that could cause actual results to differ materially, including risks related to preclinical and clinical development, regulatory review and timing, manufacturing, and financing. FDA INTERACT feedback is preliminary, non-binding scientific advice and does not constitute agreement on, or approval of, any clinical trial, endpoint, or marketing application. Glafabra undertakes no obligation to update any forward-looking statement except as required by law.

Notice Regarding Testing the Waters

Glafabra is considering a capital raise and is “Testing the Waters” under Regulation Crowdfunding. This communication is not an offer to sell, or the solicitation of an offer to buy, any securities, and no money or other consideration is being solicited. Any indication of interest involves no obligation or commitment of any kind. No offer to buy securities can be accepted, and no part of the purchase price can be received, until an offering statement is filed, and then only through the BioTech Funding Portal platform.

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