Iterion Therapeutics Shows Promising Data for Tegavivint Combo Therapy in Lung Cancer Patients

HOUSTON, Sept. 22, 2026 /CourierPR/ -- Iterion Therapeutics, a clinical-stage biopharmaceutical company dedicated to advancing the treatment of Wnt-driven cancers, today announced promising results from an investigator-sponsored Phase 1b study evaluating tegavivint in combination with osimertinib as first-line therapy for patients with metastatic EGFR-mutated non-small cell lung cancer (NSCLC). The study, conducted at The Ohio State University Comprehensive Cancer Center, Arthur G. James Cancer Hospital and Richard J. Solove Research Institute, demonstrated the potential of tegavivint to improve the depth and durability of response to EGFR-targeted therapy by targeting drug-tolerant persister (DTP) cells.

The Phase 1b study, led by principal investigator Regan Memmott, M.D., Ph.D., of The Ohio State University Comprehensive Cancer Center, enrolled 15 evaluable patients with metastatic EGFR-mutated NSCLC who had not previously received an EGFR tyrosine kinase inhibitor (TKI). The patients received osimertinib 80 mg orally once daily in combination with escalating weekly intravenous doses of tegavivint (3-8 mg/kg) for the first four months, after which tegavivint was discontinued and osimertinib monotherapy was continued until disease progression. The dose-escalation portion of the study was well-tolerated, with no dose-limiting toxicities, Grade 4 or 5 events, drug-related serious adverse events, or pneumonitis of any grade. The most common drug-related adverse events were those typically associated with osimertinib treatment, including diarrhea, maculopapular rash, anemia, and fatigue, most of which were Grade 1 or 2.

The overall response rate (ORR) for all evaluable patients treated in the dose-escalation portion of the study was 79%, with complete responses (CRs) observed in 3 of 19 patients (16%), including a CR in the one patient enrolled whose lung cancer harbored a Wnt-pathway activating mutation (WPAM). The median progression-free survival (mPFS) for all evaluable patients was 19.9 months, and the median overall survival (mOS) was 48.8 months, with only 6 events occurring. Preliminary results suggest that the combination of osimertinib and tegavivint has the potential to improve the depth and durability of response by targeting DTP cells, potentially improving the clinical outcomes for patients with EGFR-mutated NSCLC.

The study's findings align with the hypothesis that increased β-catenin transcriptional activity allows a population of tumor cells to persist despite EGFR inhibition, and that targeting these drug-tolerant persister cells may deepen responses and delay the emergence of resistance. The results were presented in an oral presentation at the American Society of Clinical Oncology (ASCO) 2026 Annual Meeting (Abstract #547976).

Iterion Therapeutics is a clinical-stage oncology company developing first-in-class therapies that target cancers driven by aberrant Wnt/β-catenin signaling. The company's lead asset, tegavivint, is the first and only small-molecule inhibitor of TBL1, a critical transcriptional regulator required for nuclear β-catenin stability and oncogenic gene expression. Tegavivint has demonstrated clinical tolerability, target engagement, and monotherapy activity in multiple complex solid tumors, including advanced hepatocellular carcinoma. Iterion is advancing a focused clinical strategy anchored by its lead program in hepatocellular carcinoma, with expansion into additional Wnt-driven cancers, including pediatric and rare oncology indications. The company has received $26 million in Product Development Awards from the Cancer Prevention and Research Institute of Texas (CPRIT).

The study's findings provide early clinical evidence supporting the potential of tegavivint to improve the depth and durability of response to EGFR-targeted therapy by targeting drug-tolerant persister cells, a fundamental limitation of current treatment approaches. The results suggest that the combination of osimertinib and tegavivint may offer a more effective approach to treating EGFR-mutated non-small cell lung cancer, potentially improving patient outcomes and delaying the emergence of resistance.