“The Next Big Wave”: Radiation Therapy Drugs Track and Kill Cancer Cells

Doctors report that drugs that directly irradiate tumor cells improved the survival rate of men with advanced prostate cancer.

Although few such drugs are currently approved, this approach may be a new way to treat other cancer patients who are difficult to reach or inoperable.

The study tested a new class of medicines called radiopharmaceuticals that deliver radiation directly to cancer cells. The drug in this case is a molecule that contains two parts, a tracker and a payload that kills the cancer.

Trillions of these molecules hunt down cancer cells and get caught in protein receptors on the cell membrane. The payload emits radiation that hits tumor cells within range.

“You can treat invisible tumors. Wherever the drug reaches, the drug reaches the tumor cells,” he said, although not involved in the study, but supporting the development of such drugs. Dr. Frank Lin, who heads the Department of the National Cancer Institute, said.

The results were announced Thursday by the American Society of Clinical Oncology prior to this weekend’s annual meeting. The study was funded by Novartis, a pharmaceutical company that will seek approval in the United States and Europe later this year.

If the cancer is localized to the prostate, the body is irradiated or transplanted into pellets.

However, these methods do not work well for more advanced prostate cancer. Each year, about 43,000 men in the United States are diagnosed with prostate cancer metastases and hormone blockade treatments are no longer effective.

This study tested new ways to receive radiation therapy for such patients.

It was attended by 831 men with advanced prostate cancer. Two-thirds received radiation therapy and the rest were used as a comparison group. Patients received up to 6 IV medications every 6 weeks.

Approximately two years later, the performance of patients receiving the drug improved on average. The cancer was stopped for almost nine months, compared to about three months for others. The survival rate was also good, about 15 months compared to 11 months.

The benefits may not seem that great, but “there aren’t many options for these patients,” said Dr. Lori Pierce, chairman of ASCO, a cancer radiation expert at the University of Michigan. ..

Radioactivity can reduce the production of blood cells, which can cause anemia and coagulation problems in patients. In this study, 53% of patients had serious side effects, compared with 38% of patients in the comparison group. Both groups were allowed to receive other treatments.

The results will pave the way for government approval and raise interest in radiation therapy drugs, Hayashi said.

Others already in use include Novartis Lutasera for rare types of cancer of the stomach and intestines.

Bayer’s Xofigo is also approved for men whose prostate cancer has spread to the bone but not elsewhere. Xofigo targets areas where the body is trying to repair bone loss due to tumor damage, but it does not directly target where the prostate cancer cells are located in the body.

“This is the first time for prostate cancer,” Lin said, because the study drug targets tumor cells.

Dr. Charles Knos, who worked on the standards for radiopharmaceutical research at the National Cancer Institute before leaving the University of Kentucky’s Marquee Cancer Center, said, “It will be a major driver of cancer research over the next decade. Let’s do it. ” It will be the next big wave of treatment development. “

Drugs being tested for melanoma, breast cancer, pancreatic cancer, and other cancers have “great potential,” said Dr. Mary Ellen Taprin of the Dana-Farber Cancer Institute in Boston, enrolling patients in the study. , Review the data.

For prostate cancer, “the range of future strategies will expand,” including early-stage diseases and other treatments, said Dr. Michael Morris, research leader at the Memorial Sloan-Kettering Cancer Center in New York. T.

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The Associated Press’s Department of Health Sciences is supported by the Department of Science Education at the Howard Hughes Medical Institute. AP is solely responsible for all content.