Canadian cancer researchers are at the forefront of global efforts to test targeted alpha therapy, a novel cancer treatment approach that oncologists believe could revolutionize how cancer is treated at the cellular level. This therapy leverages radioactive alpha particles to disrupt the DNA of cancer cells, offering a more potent and less harmful alternative to existing treatments.
How Targeted Alpha Therapy Works
Targeted alpha therapy falls under the radioligand therapy umbrella, where molecules are designed to bind specifically to cancer cells. Once these molecules are injected into the body, they release radioactive particles that kill the tumors. Unlike approved treatments that use beta particles, alpha particles emit more powerful radiation over a shorter range.
Dr. François Bénard from the University of British Columbia likens beta particle treatments to throwing golf balls in a glass house, causing damage over a wide area. In contrast, alpha therapy is like "throwing a bowling ball," causing more damage in a limited area.
Clinical Trials and Potential Applications
Several targeted alpha therapies are in the final testing stages and may be ready for consideration by Health Canada and international regulators in the coming years. Researchers are exploring its potential in treating various cancers, including pancreatic, prostate, breast cancer, and neuroendocrine cancer.
Dr. Gerald Batist, director of the Segal Cancer Centre at Montreal's Jewish General Hospital, is involved in multiple clinical trials assessing targeted alpha therapy for various cancers. One trial is testing a method of treating prostate cancer by embedding beads laden with alpha particles at the site of pancreatic cancer.
One clinical trial, also taking place at Sunnybrook Health Sciences Centre in Toronto and London Health Sciences Centre in London, Ontario, explores the use of the alpha-emitting radioactive isotope actinium-225 on neuroendocrine cancer.
Dr. David Laidley, a nuclear oncologist at London Health Sciences Centre, noted the potency of actinium particles, stating, "Because these actinium particles are extremely powerful and emit a lot of radiation in a very short distance, we're really able to cause a significant amount of damage to those tumours."
Challenges and Future Prospects
Despite its promise, challenges remain in making targeted alpha therapy widely accessible. Only a few locations worldwide can produce the rare radioactive isotopes needed for these treatments. One such facility is TRIUMF, a particle accelerator in Vancouver.
Cost is another significant factor, with treatments expected to cost tens of thousands of dollars per dose. For instance, Lutathera, a radiopharmaceutical treatment for neuroendocrine cancer, costs $35,000 per dose, while Pluvicto, for prostate cancer, costs $27,000 per dose, with a typical course involving four to five doses.
Pharmaceutical Industry Investment
The pharmaceutical industry's belief in targeted alpha therapy is evident in recent investments. Major players like Eli Lilly, AstraZeneca, and Bristol Myers Squibb have spent around $10 billion in deals to acquire or partner with companies developing radiopharmaceuticals.
Novartis, a Swiss drugmaker, spent approximately $6 billion acquiring radiopharmaceutical startups that developed Lutathera and Pluvicto.
Dr. Bénard describes targeted alpha therapy as an evolution in cancer treatment, building on advances in creating molecules that can carry radioactive isotopes to cancer cells. He notes the excitement surrounding multiple companies advancing these compounds through late-stage clinical trials, bringing them closer to approval.
