Finding donors for transplants ‘easier now’
Baltimore, July 7, 2011
Identifying a suitable donor for leukemia and lymphoma patients who need bone marrow transplants may be far easier now, according to scientists at the John Hopkins Kimmel Cancer Center.
Two clinical trials showed transplant results with half-matched bone marrow or umbilical cord blood are comparable to fully matched tissue, thanks in large part to the availability of effective antirejection drugs and special post-transplant chemotherapy, they added.
Plans are under way for a four-year randomized trial for so-called haploidentical marrow or cord blood transplants in 380 patients to begin late this year or early next year. Many large medical centers, including Johns Hopkins, are expected to participate.
The results of the two studies are good news, Hopkins researchers say, because they address the problem faced by patients when no family members are a complete match for the patient’s tissue type.
Although patients and physicians may then seek donors through national registries, as many as half or more of patients looking for matches in these registries don’t find one, and the search can take weeks to months.
During this time, a patient’s disease can progress, noted bone marrow transplant expert Ephraim Fuchs, MD, who added that it is especially difficult for minorities to find matches because of their underrepresentation in national registries.
“People are dying waiting for matched donors from a registry,” said Fuchs, associate professor of oncology at the Johns Hopkins Kimmel Cancer Center.
In the clinical trials, investigators from the Blood and Marrow Transplant Clinical Trials Network at 27 medical centers tested two types of transplants, those from half-matched (or haploidentical) bone marrow or cord blood, and published their results in the July 14 issue of Blood.
Results of the two trials show one-year survival rates of 54 percent for cord blood transplant and 62 percent for haploidentical marrow. Survival without disease progression at one year was 46 percent for cord blood and 48 percent for haploidentical marrow.
The investigators say this is comparable to survival achieved by similar patients undergoing transplants from fully matched siblings or unrelated adult donors.
“Ten years ago, it was unthinkable to do a haploidentical transplant,” said Fuchs, who led the haploidentical transplant clinical trial. – TradeArabia News Service