#95-54
Contact: Mona S.Rowe,(516) 282-2345
or
Diane Greenberg, (516)
282-2347
Mailed 9/21/95
Brookhaven's collaborators on the project are the University Medical Center at Stony Brook, in New York, and the Veterans Affairs Medical Center, in Tucson, Arizona.
In clinical trials sanctioned by the U.S. Food & Drug Administration, about 80 percent of the 40 patients treated with a single dose of the tin compound experienced substantial relief from their pain. Some patients became completely pain free for as long as 12 months.
The new compound is tin-117m DTPA, a radioisotope-labeled compound developed by Brookhaven medical researchers. It has no sedative effect.
The radioisotope tin-117m is produced at either a research reactor at Brookhaven or one at Oak Ridge National Laboratory in Tennessee. It is then attached to a pharmaceutical known as DTPA. When given to patients intravenously, tin-117m DTPA localizes preferentially in bone rather than in normal soft tissue or bone marrow.
In addition, tin-117m emits electrons that have a very short range in tissue. Because of this, tumors on the bone receive up to 50 times more dose than radiation-sensitive bone marrow. Thus, tin-117m does not suppress the bone marrow's production of white blood cells or platelets, retaining the body's ability to fight infection and clot blood. This eliminates another major side effect of other radiopharmaceuticals also devised to deal with bone pain.
Developmental work on tin-117m began at Brookhaven Lab in the late 1980s. The first clinical trials started in 1992, with a group of 10 patients. This study led to a 50-patient trial to determine the minimum dose needed to relieve bone pain and the maximum tolerated by bone marrow. The current trial is an extension of the previous one, but also concentrates on the compound's safety, efficacy and lack of toxicity.
Diatech will also be sponsoring large-scale clinical trials involving major medical centers worldwide. In these trials, patients will be given either a single therapeutic dose of the tin compound or one of the other radiopharmaceutical products already on the market to relieve bone cancer pain. Neither the patient nor the doctor will know which product is being administered.
A separate future trial, conducted jointly by Brookhaven Lab and Stony Brook, will use higher doses of the tin compound, since increasing doses may also increase the rate at which patients respond to the treatment. Additionally, the researchers will be evaluating how much time it takes for the onset of relief and how long the pain-free intervals last.
Research and development of the tin compound at Brookhaven is funded by the Office of Health and Environmental Research, within the U.S. Department of Energy's Office of Energy Research.
Brookhaven National Laboratory carries out basic and applied research in physical, biomedical and environmental sciences and in selected energy technologies. Associated Universities, Inc., a non-profit research management organization, operates the Laboratory under contract with the Department of Energy.