Genprex Announces New Research Identifying TROP2 as a Potential Predictive Biomarker to Reqorsa® Gene Therapy in Lung Cancer

Research to be Presented at the 2026 EORTC-NCI-AACR Symposium Links TROP2 Expression to Treatment Response and Explores its Role in Treatment Sensitivity

Findings Suggest Low TROP2 Expression is Associated with Primary Resistance to REQORSA and May Help Guide Patient Selection

AUSTIN, Texas, Nov. 4, 2026 — Genprex, Inc. ("Genprex" or the "Company") (NASDAQ: GNPX), a clinical-stage biotechnology company developing gene therapies designed to restore tumor-suppressor function in cancer and insulin-producing function in diabetes, today announced new research identifying TROP2 expression as a potential predictive biomarker of response to its lead drug candidate, Reqorsa^® (quaratusugene ozeplasmid), a gene therapy product, will be presented at the 2026 EORTC-NCI-AACR Symposium on Molecular Targets and Cancer Therapeutics, taking place November 18-20, 2026 in Barcelona, Spain.

The research collaborators found that low TROP2 expression was consistently associated with resistance to REQORSA across multiple preclinical models of non-small cell lung cancer (NSCLC). This finding was also supported by analysis of pretreatment tumor biopsies from patients enrolled in a clinical trial evaluating REQORSA.

"Discovering an applicable biomarker of response is a meaningful step toward a more precise approach to treating lung cancer with REQORSA," said Ryan Confer, President and Chief Executive Officer of Genprex. "These data show that low TROP2 expression was associated with primary resistance across multiple preclinical models, and this was supported by analysis of patient biopsies from a clinical trial. If confirmed in further studies, TROP2 could not only help us enhance our clinical trials by recruiting and selecting more applicable patients, but, more importantly, benefit future patients by ultimately delivering potentially more effective, personalized treatment options. This work reflects our commitment to a precision-medicine approach to treating lung cancer."

The TUSC2 tumor suppressor protein expression is downregulated or absent in more than 80% of NSCLC cases and nearly all small cell lung cancers. Previous studies have shown that REQORSA has antitumor activity, including in models resistant to targeted therapies and in immunotherapy-resistant KRAS/LKB1-mutant NSCLC. REQORSA's effects are mediated by inhibiting MAPK and mTOR signaling, inducing cell-cycle arrest and apoptosis, and activating antitumor immune responses.

Key findings from the research include:

• TROP2 expression associated with resistance: Approximately 50% of 10 NSCLC cell lines and 50% of 12 patient derived organoid models evaluated showed primary resistance to TUSC2 gene delivery. Protein-expression analyses consistently identified low TROP2 expression as a marker associated with resistance across multiple preclinical models.
• Supporting clinical evidence: Analysis of pretreatment tumor biopsies from patients enrolled in a TUSC2 gene therapy clinical trial supported the association between TROP2 expression and treatment response.
• TROP2 modulation influenced treatment sensitivity: Experimental manipulation of TROP2 expression altered TUSC2-induced cancer cell death, suggesting that TROP2-dependent signaling may play a role in therapeutic response. Further research is underway to understand these context-dependent effects.

Collectively, the findings identify TROP2 as a potential predictive biomarker for response to REQORSA and suggest that modulating TROP2 signaling may be a novel strategy to enhance the therapeutic efficacy of REQORSA in NSCLC. While these findings provide preclinical and supportive clinical evidence, additional research and prospective clinical evaluation will be required to establish TROP2's predictive utility in patients receiving REQORSA.

The featured Genprex-supported poster is to be presented at the 2026 EORTC-NCI-AACR Symposium on Molecular Targets and Cancer Therapeutics:

Title: TROP2 Predicts Response to TUSC2 Gene Therapy (Quaratusugene Ozeplasmid) and Its Modulation Sensitizes Non-Small Cell Lung Cancer to Treatment
Conference: 2026 EORTC-NCI-AACR Symposium on Molecular Targets and Cancer Therapeutics
Topic: Drug Resistance and Modifiers
Session Date and Time: Wednesday, Nov. 18, 2026
Time: 12:00–6:00 p.m. CET
Abstract Number: 108
Poster Board Number: PB-108
Location: CCIB, Barcelona, Spain

The EORTC-NCI-AACR 2026 poster is expected to be available on Genprex's website following the presentation, subject to applicable conference disclosure requirements.

About Reqorsa^® Gene Therapy
Reqorsa^® (quaratusugene ozeplasmid), a gene therapy product, consists of a plasmid containing the TUSC2 gene encapsulated in non-viral lipid-based nanoparticles in a lipoplex form (the Company's Oncoprex^® Delivery System), which has a positive charge. REQORSA is injected intravenously and specifically targets cancer cells. REQORSA is designed to deliver the functioning TUSC2 gene to negatively charged cancer cells while minimizing uptake by normal tissue. Laboratory studies conducted at MD Anderson show that the uptake of TUSC2 in tumor cells in vitro after REQORSA treatment was 10 to 33 times the uptake in normal cells.

Cautionary Language Concerning Forward-Looking Statements
Statements contained in this press release regarding matters that are not historical facts are "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995. These forward-looking statements are made on the basis of the current beliefs, expectations and assumptions of management, are not guarantees of performance and are subject to significant risks and uncertainty. These forward-looking statements should, therefore, be considered in light of various important factors, including those set forth in Genprex's reports that it files from time to time with the Securities and Exchange Commission and which you should review, including those statements under "Item 1A – Risk Factors" in Genprex's Annual Report on Form 10-K for the year ended December 31, 2025.

Because forward-looking statements are subject to risks and uncertainties, actual results may differ materially from those expressed or implied by such forward-looking statements. Such statements include, but are not limited to, statements regarding: Genprex's ability to advance the clinical development, manufacturing and commercialization of its product candidates in accordance with projected timelines and specifications, including identifying TROP2 expression as a potential predictive biomarker of response to REQORSA in NSCLC which has the potential of delivering more effective, personalized treatment options; the timing and success of Genprex's clinical trials, its intended regulatory submissions and any resulting regulatory approvals; the effect of Genprex's product candidates, alone and in combination with other therapies, on cancer and diabetes; Genprex's future growth and financial status, including Genprex's ability to maintain compliance with the continued listing requirements of The Nasdaq Capital Market and to continue as a going concern and to obtain capital to meet its long-term liquidity needs on acceptable terms, or at all; Genprex's commercial and strategic partnerships, including those with its third party vendors, suppliers and manufacturers and their ability to successfully perform and scale up the manufacture of its product candidates; Genprex's intellectual property and licenses; and Genprex's current expectations, estimates, forecasts and projections about the industry and markets in which it operates.

These forward-looking statements should not be relied upon as predictions of future events and Genprex cannot assure you that the events or circumstances discussed or reflected in these statements will be achieved or will occur. If such forward-looking statements prove to be inaccurate, the inaccuracy may be material. You should not regard these statements as a representation or warranty by Genprex or any other person that Genprex will achieve its objectives and plans in any specified timeframe, or at all. You are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date of this press release. Genprex disclaims any obligation to publicly update or release any revisions to these forward-looking statements, whether as a result of new information, future events or otherwise, after the date of this press release or to reflect the occurrence of unanticipated events, except as required by law.

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SOURCE Genprex, Inc.