Jun 20 2007
Investigators at St. Jude Children's Research Hospital have shown that when the cancer drug irinotecan is given in low doses for multiple days, it eliminates the need to delay treatment to perform costly genetic testing that determines if the patient is at risk for serious treatment side effects, such as neutropenia.
Neutropenia is an abnormal reduction in the numbers of immune cells, called neutrophils; the disorder leaves individuals more vulnerable to infections.
The finding means that clinicians can begin treatment sooner and eliminate the cost of this specialized test, which determines if the child carries a variation in the gene UGT1A1 that is linked to this side effect of neutropenia, said Clinton Stewart, Pharm.D., associate member of the St. Jude Department of Pharmaceutical Sciences.
"By giving the drug in small doses for two weeks instead of the standard single large dose once a month, children can begin treatment with irinotecan immediately," said Stewart, first author of a report on this study that appears in the June 20 issue of the "Journal of Clinical Oncology." Irinotecan is used to treat childhood solid tumors such as neuroblastoma, sarcomas and kidney tumors.
"This finding should help clinicians design effective and safe irinotecan treatments for individual children," said Lisa McGregor, M.D., Ph.D., assistant member of the St. Jude Department of Oncology and the report's senior author.
Other authors of this study include John Panetta, Melinda O'Shaughnessy, Stacy Throm, Charles Fraga, Thandranese Owens, Tiebin Liu, Catherine Billups, Carlos Rodriguez-Galindo, Amar Gajjar and Wayne Furman (St. Jude).
This work was supported in part by the National Institutes of Health, a Cancer Center Support Grant and ALSAC.
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