Glafabra Therapeutics Completes FDA INTERACT Meeting for Its Live-cel Fabry Disease Gene Therapy, Clarifying Its Path to an IND

FDA’s written feedback generally noted that the nonclinical package supports a proposed exploratory clinical study, recommended prioritizing plasma lyso-Gb3 as the pharmacodynamic readout, agreed that assessing eGFR is reasonable while recommending at least two years of follow-up, said a within-subject exploratory design is reasonable, and advised that manufacturing knowledge may be leveraged across the Live-cel platform with appropriate justification.

PARK CITY, Utah, August 19, 2026. Glafabra Therapeutics, a 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 better clarification of the 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 noted that the nonclinical data provided are sufficient to support the proposed exploratory, early-phase clinical study, and asked that additional characterization be included in the IND: an in vitro immortalization assay in human CD34+ cells using the intended clinical vector, integration-site analysis with clonal-dynamics and clonal-dominance data, and a risk assessment of preferential integration within or near tumor suppressor genes and proto-oncogenes.

• Pharmacodynamic biomarker. FDA agreed with assessing changes in plasma lyso-Gb3 in the exploratory trial and recommended prioritizing it, using a validated bioanalytical assay, noting that plasma Gb3 has several limitations and is not recommended for use based on available evidence. FDA also stated that Fabry biomarkers are not suitable as clinical efficacy endpoints. Consistent with that advice, Glafabra treats lyso-Gb3 as a pharmacodynamic readout rather than an efficacy endpoint.

• Trial design. FDA said a within-subject comparison, change from baseline, is reasonable for the proposed exploratory study to describe pharmacodynamic and clinical change and to inform a pivotal study, while noting that this early-phase data is unlikely to be fit-for-purpose to serve as evidence of effectiveness for a future marketing application, which must come from an adequate and well-controlled trial.

• Renal and cardiac measures. FDA agreed that assessing estimated glomerular filtration rate (eGFR) is reasonable and recommended a follow-up period of at least two years, noting that eGFR data over one year would likely not be interpretable. FDA also indicated the need to assess cardiac measures, including cardiac imaging parameters and exercise capacity. Glafabra’s intended use of eGFR as registrational primary endpoint was not addressed at INTERACT and will be the subject of future Pre-IND and End-of-Phase-1 discussions.

• Platform leverage. FDA advised that where the lentiviral vector backbone, packaging system, manufacturing process, and cell processing steps are conserved, certain chemistry, manufacturing, and controls (CMC) data may be leveraged across programs with appropriate scientific justification, either submitted directly or incorporated by reference from an existing IND or Master File. FDA noted that each program advances under its own IND and that transgene-specific elements, including potency assays and release specifications, must be established independently.

• Redosing. FDA declined to provide comprehensive feedback on re-administration because the plan was not yet described in sufficient detail. In the meeting verbal discussion, FDA indicated that additional preclinical data would be needed to define the threshold at which redosing is warranted.

• A defined path forward. FDA recommended a Pre-IND meeting and an End-of-Phase-1 meeting to discuss study design, population, endpoints, and other design features, and asked that the dosing and re-administration strategy be detailed at the Pre-IND meeting. FDA noted that the level of detail in the submission limited the feedback it could provide and recommended a Pre-IND meeting prior to IND submission.

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 now have the Agency’s written view on the questions that matter most: our nonclinical package, our biomarker, our study design, and whether the platform can be leveraged across programs. We also came away with the Agency’s list of what to develop further before the Pre-IND meeting, which FDA recommended we request before we submit the IND. 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 being 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.

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.