NEW YORK – Genprex on Tuesday said it will advance to the Phase II portion of the Acclaim-1 clinical trial of Reqorsa (quaratusugene ozeplasmid) with AstraZeneca's Tagrisso (osimertinib) in patients with EGFR-mutated non-small cell lung cancer.
In the Phase I dose escalation portion of the trial, Reqorsa was well tolerated with no dose-limiting toxicities and early signs of efficacy.
Reqorsa is a gene therapy product designed to restore activity of the TUSC2 gene in cancer cells. TUSC2 is a tumor suppressor gene whose expression is decreased in 82 percent of patients with NSCLC. In preclinical studies in mouse xenograft models, Reqorsa improved control of EGFR-mutant tumors when combined with Tagrisso. Reqorsa has also been shown to simultaneously inhibit the EGFR and AKT oncogenic kinase pathways in vitro and in vivo, supporting the hypothesis that the drug may have synergistic effects with other cancer drugs such as EGFR inhibitors by blocking resistance pathways.
In the Acclaim-1 Phase I study involving eight patients with EGFR-mutant NSCLC who had progressed on Tagrisso, one patient had a partial remission after 11 cycles of therapy, and another had stable disease after nine cycles. A safety review committee determined that the recommended Phase II dose of Reqorsa will be 0.12 mg/kg, the highest dose tested in Phase I.
The Austin, Texas-based company plans to commence the Phase II expansion portion of the trial in the third quarter of 2023. Investigators will enroll about 66 patients, half of whom received Tagrisso previously and the other half having received Tagrisso and chemotherapy. An interim analysis will be conducted when 19 patients in each cohort have been treated. The primary endpoint of the trial will be progression-free survival.
Genprex is also conducting a Phase I/II trial, dubbed Acclaim-2, of Reqorsa with Merck's Keytruda (pembrolizumab) in patients with previously treated non-small cell lung cancer.