A radioactive drug that treats the pain of metastatic bone cancer has been approved for marketing by the Food and Drug Administration.
The drug -- called Metastron -- is a strontium-89 chloride injection. It was approved by the FDA on Friday based on studies led by the Kansas University Medical Center.
"This is good news for people whose cancer has spread to the bones, particularly prostate or breast cancer patients," said Dr. Ralph G. Robinson, professor of diagnostic radiology at the medical center, in a press release.
Robinson spearheaded the development of Metastron in the United States. In 1977, he filed the first investigational new drug application to study the drug in this country. In the intervening 16 years, the KU Medical Center has treated more than 550 patients with Metastron.
Robinson's studies showed that Metastron relieved pain in 80 percent of patients with prostate or breast cancer that had spread to their bones. His recent studies have revealed that the drug also may slow the growth of metastatic bone tumors.
The drug works by delivering radiation directly to the bone tumors, Robinson said. The strontium component acts as the delivery system, and the 89 represents a radioactive isotope of strontium. Strontium is chemically like calcium, which is readily absorbed by bone.
Although Metastron does not cure bone cancer, it can help make patients' live more comfortable. Once the drug is injected, it is effective for three months or more. Another injection can be given after the first wears off.
Patients in which conventional treatment for cancer has not worked would be considered candidates for Metastron therapy.
The drug was approved for use in Canada almost seven years ago and has been on the market in Europe for 18 months.