First US Patient Receives Innovative Radiopharmaceutical Treatment for Advanced Breast Cancer

In a groundbreaking development, the Mayo Clinic has successfully treated the first patient in the United States with a novel radiopharmaceutical therapy targeting metastatic breast cancer. This treatment is part of an ongoing international clinical trial aimed at exploring advanced options for cancer therapy. The therapy involves actinium-225, a highly potent alpha-emitting radiopharmaceutical initially developed to combat certain gastroenteropancreatic neuroendocrine tumors. Unlike traditional treatments, this alpha therapy is designed to specifically target cancer cells, delivering intense radiation directly to the malignant cells while minimizing damage to healthy tissue.

The innovative treatment was administered at Mayo Clinic's Florida site, marking the first application of this therapy in the U.S. for a breast cancer patient with metastatic disease. The trial is a phase 1b/2 open-label study conducted across several Mayo Clinic locations, including Minnesota, Arizona, and Florida, with plans to involve approximately 20 other sites nationwide.

Dr. Geoffrey Johnson, a leading radiology researcher at Mayo Clinic, emphasizes that such therapies utilize radioactive medicines carefully engineered to seek out and destroy cancer cells with high precision. This particular approach leverages alpha particles, which are significantly more powerful than beta particles traditionally used in radiotherapy. Dr. Johnson explains, "Alpha emitters can deliver a concentrated punch over a very short distance, making them highly effective at killing targeted cancer cells without harming the surrounding healthy tissue."

Preclinical studies have demonstrated promising results, showing that actinium-225 DOTATATE, which targets somatostatin receptor subtype 2, could be effective for treating estrogen receptor-positive metastatic breast cancer. Developed by RayzeBio Inc., a subsidiary of Bristol Myers Squibb, this therapy is still under investigation but holds great potential as a next-generation cancer treatment.

Mayo Clinic currently conducts nearly 20 active radiopharmaceutical clinical trials and is leading in the use of modern therapies, such as lutetium dotatate and lutetium PSMA, for neuroendocrine and prostate cancers. These therapies differ from traditional radiation because the alpha-emitting radiopharmaceuticals deliver much more powerful effects in a targeted manner, potentially transforming cancer treatment paradigms.

This innovative approach signifies a major advancement in precision oncology, offering hope for more effective and less invasive treatments for patients with advanced and metastatic cancers.