On May 28, 2025 Genprex, Inc. ("Genprex" or the "Company") (NASDAQ: GNPX), a clinical-stage gene therapy company focused on developing life-changing therapies for patients with cancer and diabetes, reported that its research collaborators presented positive preclinical data and research from studies of GPX-002, the Company’s diabetes gene therapy drug candidate, in an oral presentation at the American Society of Gene and Cell Therapy’s (ASGCT) (Free ASGCT Whitepaper) 28th Annual Meeting which took place May 13-17, 2025 in New Orleans, Louisiana (Press release, Genprex, MAY 28, 2025, View Source [SID1234653439]).
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"We are pleased with the preclinical studies evaluating our novel gene therapy in diabetes, and we are proud to have been selected to present this data before an audience of innovators in cell and gene therapy," said Ryan Confer, President and Chief Executive Officer at Genprex. "We believe GPX-002 offers a promising opportunity for curative therapy in diabetes, which could impact the millions of patients suffering from this debilitating disease."
The oral presentation details for the Genprex-supported abstract:
Abstract Title: Immune Modulation Sustains Alpha Cell Reprogramming and Mitigates Immune Responses to AAV in a Diabetic Non-Human Primate Model
Session Title: Challenges in Immunological Responses to Therapeutic Interventions
Presenter: Hannah Rinehardt, MD, University of Pittsburgh Medical Center
Presentation Date: May 16, 2025
Presentation Time: 4:15 – 4:30 p.m. CT
Location: Room 278-282
In the oral presentation, Dr. Rinehardt discussed GPX-002, the diabetes gene therapy, which uses intraductal infusion of recombinant adeno-associated virus (rAAV) to deliver the Pdx1 and MafA genes. The gene therapy converts alpha cells into beta-like cells that secrete insulin physiologically, reversing diabetes in mouse models, where immunosuppression was not necessary. Researchers evaluated the immune response to direct infusion of rAAV into the pancreatic duct of Non-Human Primates (NHPs) with streptozotocin-induced diabetes and evaluated how to best manage immune responses.
Diabetes was induced with streptozotocin (STZ) in cynomolgus macaques, a type of NHP. NHPs received retrograde intraductal infusion of rAAV via laparotomy for precise delivery to the pancreas. rAAV capsids were chosen based on tropism for endocrine cells, and pre-existing neutralizing antibody titers (NAbs) were negative. Blood work, including serum C peptide and IV glucose tolerance tests, were serially obtained to monitor therapeutic efficacy. Immune response monitoring was performed for up to 4 months post-infusion and included serial NAbs, ELISpot assays, and immunophenotyping. Pancreatic tissues were analyzed using IHC and RNA-scope for beta cell markers, as well as single-cell RNA transcriptomics.
Expression of viral proteins occurs for a limited period of time after rAAV infection, since the infection doesn’t produce new AAV virus. One-month post-infusion, NHPs showed improved glucose tolerance and reduced insulin requirements. In the following months, using steroid-sparing regimens, increases in pancreatic B and T lymphocyte populations were noted on scRNA sequencing. Temporary immunosuppression (IS), using a combination of rituximab, rapamycin, and steroids for a 3-month course is largely effective at preventing anti-viral immunity. However, discontinuation of IS at 3 months post-infusion led to an immune response afterwards, indicating that IS in NHPs may need to be continued longer.
In conclusion, the novel rAAV gene therapy demonstrated that infusion of rAAV directly into the pancreatic duct of NHPs improves glucose tolerance but induces an anti-viral immune response which can degrade the improvement in glucose tolerance. The anti-viral immune response in NHPs can be largely prevented by administration of a multi-agent IS that leads to sustained therapeutic effects.
Researchers are continuing preclinical studies of GPX-002 therapy in NHP models of both Type 1 and Type 2 diabetes to generate additional data, and present studies are evaluating viral efficacy after six months of immunosuppression.
For more in-depth preclinical data supporting GPX-002, please review Genprex’s Corporate Presentation.
About GPX-002
GPX-002, which has been exclusively licensed from the University of Pittsburgh, is currently being developed using the same construct for the treatment of both Type 1 diabetes (T1D) and Type 2 diabetes (T2D). The same general novel approach is used in each of T1D and T2D whereby an adeno-associated virus (AAV) vector containing the Pdx1 and MafA genes is administered directly into the pancreatic duct. In humans, this can be done with a routine endoscopy procedure. In T1D, GPX-002 is designed to work by transforming alpha cells in the pancreas into functional beta-like cells, which can produce insulin but may be distinct enough from beta cells to evade the body’s immune system. In vivo, preclinical studies show that GPX-002 restored normal blood glucose levels for an extended period of time in T1D mouse models. In T2D, where autoimmunity is not at play, GPX-002 is believed to rejuvenate and replenish exhausted beta cells.