Genprex pinpoints key biomarkers to predict Reqorsa gene therapy success at ASCO

Genprex (NASDAQ:GNPX) announced the official abstract publication of positive clinical biomarker data for its lead oncology candidate, Reqorsa gene therapy (quaratusugene ozeplasmid), at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting.

The Austin, Texas-based clinical-stage biotechnology firm reported that an analysis of tissue samples from patients treated in its lung cancer programs identified Trop-2 and PTEN as functional predictive biomarkers.

The findings provide the company with a clearer clinical pathway to pre-screen and select high-responder patient populations for its ongoing registrational studies.

The specialized biomarker analysis evaluated 18 total lung cancer patients, tracking historical tissue samples via immunohistochemistry H-scores to determine protein density.

In patients diagnosed with non-small cell lung cancer (NSCLC), a distinct correlation emerged: individuals expressing higher Trop-2 baseline levels (H-score greater than 100) alongside lower levels of the PTEN tumor suppressor (H-score less than 100) experienced significantly prolonged progression-free survival (PFS).

This survival advantage did not carry over into the small cell lung cancer (SCLC) cohort, indicating that the predictive value of this specific dual-protein signature is highly histology-dependent.

Additionally, secondary intensity staining models demonstrated a strong, though not yet statistically significant, trend linking top-tier (3+) Trop-2 expression directly to extended PFS benefits.

Reqorsa functions by utilizing Genprex’s non-viral Oncoprex Delivery System, encapsulating specific gene-expressing plasmids inside positively charged lipid nanoparticles.

When injected intravenously, the nanoparticles electrostatically target negatively charged cancer cells to re-express the missing TUSC2 tumor suppressor protein, forcing tumor cell death and disrupting active replication pathways.

Management indicated that the newly validated intensity staining profiles will be used immediately to refine patient enrollment guidelines.

Specifically, the data will help streamline the ongoing Acclaim-1 Phase 1/2 trial—which combines Reqorsa with AstraZeneca’s Tagrisso for advanced EGFR-mutant NSCLC—and the Acclaim-3 trial, which pairs the gene therapy with Genentech’s Tecentriq as a maintenance treatment for extensive-stage SCLC