Inmune Bio Inc. Announces New Preclinical Data At Aacr 2026 Demonstrating Inb03 Overcomes Resistance and Reduces Metastases in Her2-Positive Breast Cancer Models

Published: 2026-04-16 09:20:42 ET INMB

Published on 04/16/2026 at 09:20 am EDT

INmune Bio Inc. announces new preclinical data for INB03 (XPro1595 for oncology). The data will be presented at the American Association for Cancer Research (AACR) Annual Meeting 2026 in San Diego on April 17-22. The poster, titled, ?Soluble TNF blockade overcomes tyrosine kinase inhibitors resistance in HER2-positive breast cancer,?

details how INB03 (?XPro??), a first-in-class dominant-negative soluble TNF (sTNF) inhibitor, significantly enhances the anti-tumor activity of the tyrosine kinase inhibitors (TKIs) lapatinib and tucatinib while reducing metastatic spread to the brain, lungs, and liver in HER2-positive breast cancer models. It was authored by collaborators from the Instituto de Biología y Medicina Experimental (IBYME-CONICET) in Buenos Aires, Argentina. Overcoming Resistance in Vitro: The combination of INB03 (10 µg/mL) with either lapatinib (1 µM) or tucatinib (10 µM) produced statistically superior inhibition of cell proliferation and migration in both HER2+ JIMT-1 and brain-metastatic JIMT-1 Br3-luc cell lines compared to TKIs alone (p < 0.05 to p < 0.0001).

Enhanced Tumor Control In Vivo: In female nude mice bearing JIMT-1 or JIMT-1 Br3-luc tumors, INB03 + TKI combinations markedly slowed tumor growth compared to TKIs alone. Reduction of Metastatic Spread: The addition of INB03 significantly reduced the incidence of metastases to brain, lung, and liver (quantified by ex-vivo IVIS luminescence imaging). Notably, it further enhanced tucatinib?s effect on lung metastases (p < 0.05 to p < 0.0001).

Mechanism of Action: These results support prior research showing that selective sTNF neutralization with INB03 down-regulates MUC4, a protein that shields the HER2 molecule and prevents therapies from binding effectively. XPro? is a next-generation inhibitor of tumor necrosis factor (TNF) that is currently in clinical trial and acts differently than currently available TNF inhibitors in that it neutralizes soluble TNF (sTNF), without affecting trans-membrane TNF (tmTNF) or TNF receptors.

XPro? could have potential substantial beneficial effects in patients with neurologic disease by decreasing neuroinflammation. For more information about the importance of targeting neuroinflammation in the brain to improve cognitive function and restore neuronal communication visit this section of INmune Bio?s website.