Genprex, Inc. (NASDAQ: GNPX), a clinical-stage gene therapy company based in Austin, Texas, announced a new Sponsored Research Agreement (SRA) with The University of Texas MD Anderson Cancer Center to investigate biomarkers that may predict patient response to Reqorsa Gene Therapy (quaratusugene ozeplasmid) in non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). The agreement extends a research relationship between the two parties that dates to 2010, with multiple prior SRAs completed over that period. Financial terms were not disclosed.
Reqorsa is a non-viral, lipid nanoparticle-based gene therapy that delivers the TUSC2 tumor suppressor gene — absent or downregulated in the majority of lung cancers — directly to tumor cells via intravenous administration. Re-expression of TUSC2 protein is designed to restore apoptotic signaling, disrupt oncogenic kinase activity, and modulate immune responses within the tumor microenvironment. The candidate holds FDA Fast Track Designation for both NSCLC and SCLC indications, and FDA Orphan Drug Designation for SCLC.
The research under the new SRA will focus on TROP2 (trophoblast cell-surface antigen 2) and PTEN (phosphatase and tensin homolog) as candidate predictive biomarkers for Reqorsa response. Preclinical work by Genprex’s research collaborators has identified both proteins as potential indicators of which patients are more likely to respond to treatment. TROP2, a transmembrane glycoprotein overexpressed across a range of solid tumors, has become a target of broad oncology interest; PTEN, a tumor suppressor gene, has established roles in cancer risk assessment and treatment planning across multiple tumor types. The SRA is intended to translate these preclinical observations into a framework for patient selection in Genprex’s ongoing clinical programs.
The findings are intended to inform patient enrichment strategies for two active Phase I/II studies. Acclaim-1 (NCT04486833) is evaluating Reqorsa in combination with AstraZeneca’s Tagrisso (osimertinib) in patients with late-stage EGFR-mutant NSCLC who have progressed on osimertinib or osimertinib-containing regimens. The trial has completed its Phase I dose escalation portion, which showed no dose-limiting toxicities at twice the starting dose. One patient in the Phase I cohort achieved a partial remission that has been maintained through approximately 42 months of continued treatment. Acclaim-3 (NCT05703971) is evaluating Reqorsa in combination with Genentech’s Tecentriq (atezolizumab) as maintenance therapy for patients with extensive-stage SCLC who did not progress on initial atezolizumab plus chemotherapy. That trial is currently enrolling patients in the Phase II expansion cohort following Phase I dose escalation with no dose-limiting toxicities; one patient in the Phase I portion achieved an unconfirmed partial remission after 24 cycles, with treatment continuing beyond 18 months.
The post-osimertinib NSCLC setting addressed by Acclaim-1 represents a patient population with limited approved options following progression on the standard-of-care third-generation EGFR inhibitor, where platinum-based chemotherapy remains a common salvage approach. The SCLC maintenance setting addressed by Acclaim-3 similarly reflects an area of unmet need, where atezolizumab-based maintenance offers modest incremental benefit over chemotherapy alone. Biomarker-driven patient selection in both settings could materially affect the probability of demonstrating clinical benefit in the Phase II expansion cohorts.
The TUSC2 gene therapy approach pursued by Genprex operates through a mechanism distinct from targeted kinase inhibition or checkpoint blockade, aiming to restore a lost tumor suppressor pathway rather than inhibit a specific oncogenic driver — a differentiated mechanistic rationale that the biomarker research is designed to support with patient selection data.