German pharmaceutical and life sciences company Bayer AG (ETR:BAYN) (OTC:BAYRY) announced on Tuesday that it has initiated a Phase I clinical trial for 225Ac-GPC3 (BAY 3547926), an investigational targeted alpha radiopharmaceutical being developed to treat advanced hepatocellular carcinoma (HCC) by targeting tumours expressing Glypican-3 (GPC3).

The therapy combines a high-affinity antibody with the alpha-emitting isotope actinium-225 to induce lethal DNA double-strand breaks in cancer cells.

The first-in-human, dose-escalation study will evaluate BAY 3547926 as both a monotherapy and in combination settings, focusing on safety, tolerability and early efficacy outcomes in patients with GPC3-positive HCC. GPC3 is overexpressed in 70-75% of HCC cases, making it a promising therapeutic target.

Liver cancer, including HCC, is the third leading cause of cancer-related deaths globally, with nearly 900,000 new cases annually. In the United States it is the fastest-rising cause of cancer mortality.

This programme is Bayer's first targeted radiopharmaceutical for liver cancer and the third in its growing targeted alpha therapy portfolio, following 225Ac-Pelgifatamab and 225Ac-PSMA-Trillium, both under investigation for advanced prostate cancer.