Austin – November 04, 2026 -- Genprex, Inc. (NASDAQ: GNPX) reported that low TROP2 expression was consistently associated with primary resistance to its lead gene therapy Reqorsa (quaratusugene ozeplasmid) across multiple preclinical non-small cell lung cancer (NSCLC) models. The company says the finding could guide patient selection in future trials.
About half of tested NSCLC models showed primary resistance
Approximately 50% of 10 NSCLC cell lines and 50% of 12 patient-derived organoid models showed primary resistance to TUSC2 gene delivery. Protein-expression analyses identified low TROP2 expression as a marker associated with that resistance.
Patient biopsies from a TUSC2 trial back the association
Analysis of pretreatment tumor biopsies from patients enrolled in a TUSC2 gene therapy clinical trial supported the link between TROP2 expression and treatment response. The company did not disclose patient numbers or effect sizes.
CEO Ryan Confer called the biomarker discovery "a meaningful step toward a more precise approach" to treating lung cancer with Reqorsa. He said that, if confirmed, TROP2 could help Genprex recruit and select more applicable patients for its trials.
Altering TROP2 changed TUSC2-induced cancer cell death
Experimental manipulation of TROP2 expression altered TUSC2-induced cancer cell death. Genprex said modulating TROP2 signaling may be a novel strategy to enhance Reqorsa's efficacy in NSCLC, and further research is underway to understand these context-dependent effects.
The company cautioned that the evidence is preclinical and supportive-clinical only. Additional research and prospective clinical evaluation are required to establish TROP2's predictive utility in patients receiving Reqorsa.
TUSC2 loss in more than 80% of NSCLC cases defines the target population
TUSC2 tumor suppressor protein expression is downregulated or absent in more than 80% of NSCLC cases and nearly all small cell lung cancers. Reqorsa delivers the TUSC2 gene in non-viral lipid-based nanoparticles via the Oncoprex Delivery System. In laboratory studies at MD Anderson, TUSC2 uptake in tumor cells was 10 to 33 times the uptake in normal cells.
Previous studies showed antitumor activity in models resistant to targeted therapies and in immunotherapy-resistant KRAS/LKB1-mutant NSCLC. Reqorsa is being evaluated in the Acclaim-1 trial in NSCLC and the Acclaim-3 trial in small cell lung cancer. The U.S. FDA has granted Fast Track Designation to both programs and Orphan Drug designation to the small cell lung cancer program.
Poster debuts in Barcelona on Nov. 18 at EORTC-NCI-AACR
The poster, titled "TROP2 Predicts Response to TUSC2 Gene Therapy (Quaratusugene Ozeplasmid) and Its Modulation Sensitizes Non-Small Cell Lung Cancer to Treatment," will be presented in the Drug Resistance and Modifiers topic. It is scheduled for Wednesday, Nov. 18, from 12:00 to 6:00 p.m. CET at CCIB, Barcelona, as Abstract 108 on Poster Board PB-108. The symposium on Molecular Targets and Cancer Therapeutics runs Nov. 18-20, 2026.
Genprex expects to post the poster on its website after the presentation, subject to conference disclosure requirements.