National Study: New Ways To Prevent Stroke And Reduce Excess Iron In Sickle Cell Anemia

The five-year study, called Stroke With Transfusions Changing toHydroxyurea (SWiTCH), is supported by a grant of more than $18 millionfrom the National Institutes of Health (National Heart, Lung, and BloodInstitute) and includes 20 major pediatric sickle cell centers inaddition to St. Jude. The study is now being organized and will enrollthe first children in spring 2006. SCA is an inherited disease in whichthe oxygen-carrying protein in the red blood cells is abnormal, givingthe red cells a twisted (sickled) shape that can disrupt circulation,leading to pain, stroke, and other disabling and sometimes fatalcomplications.

SWiTCH holds promise for greatly simplifying and improving thelong-term care of children with the disease who have suffered strokes,according to Russell E. Ware, M.D., Ph.D., chief of the HematologyDivision at St. Jude and principal investigator of the clinical trial."Sickle cell anemia is a relentless disease that increasingly disableschildren as they grow," Ware said. "In fact, children with strokereceive difficult treatments with their own complications that must betreated. There is reason to hope that SWiTCH could finally give us abetter way to enhance the lives of these children, who suffer dailyfrom their disease and face the threat of stroke and early death."

The current treatment for children with SCA who have suffered strokesincludes monthly blood transfusions to provide red cells that are notsickled. This ongoing treatment must later be combined with nightlyinjections of a drug (Desferal ®)that eliminates excessive iron buildup caused by regular bloodtransfusions. Excessive iron damages internal organs--a conditioncalled hemochromatosis. The nightly injections of Desferal, an ironchelator, are painful and inconvenient, often prompting children toforego the injection, since iron buildup does not initially cause thechild discomfort, but the injections always do. Chelators are moleculesthat bind to metals so they can be eliminated from the body.

The goal of SWiTCH is to compare patient outcomes using bloodtransfusions with outcomes using hydroxyurea. Hydroxyurea will notcompletely eliminate the sickled red cells, but it is expected tostimulate production of enough red cells carrying fetal hemoglobin toreduce SCA symptoms. The study will also compare the efficacy of dailyat-home injections of Desferal with the less painful and moreconvenient monthly removal of blood (phlebotomy) at a medical facility.Half of the children in SWiTCH will remain on the standard treatment(transfusions and chelator) while the other half will be treated withthe alternative treatment (hydroxyurea and phlebotomy).

cludechildren who have already suffered one stroke and are at risk foradditional strokes because of blood vessel damage in their brains."This is the first study to directly compare transfusions withhydroxyurea for the treatment of SCA," Ware said. "If hydroxyurea cansuccessfully substitute for transfusions in children who already havecerebrovascular disease and damage to their brains, we will be veryinterested in also seeing if the drug can prevent this process as well.That would spare children with SCA from suffering first strokes andgreatly improve their lives."

The 20 other collaborating sites and the principal investigatorsinclude: Baylor College of Medicine (Houston, TX; Brigitta Mueller,M.D.), Children's Hospital-Boston (Boston, MA; Matthew Heeney, M.D.),Cincinnati Children's Hospital (Cincinnati, OH; Patrick Kelly, M.D.,Ph.D.), Children's Hospital of Philadelphia (Philadelphia, PA; JanetKwiatkowski, M.D.), Children's Mercy Hospital-Missouri (Kansas City,MO; Gerald Woods, M.D.), Children's Hospital at Montefiore (New York,NY; Catherine Driscoll, M.D.), National Medical Center (Washington, DC;Caterina Minniti, M.D.), Columbia University (New York, NY; MargaretLee, M.D.), Children's Healthcare of Atlanta at Scottish Rite (Atlanta,GA; Beatrice Files, M.D.), East Carolina University (Greenville, NC;Charles Daeschner, M.D.), Emory University (Atlanta, GA; Peter A. Lane,M.D.), Medical College of Wisconsin (Milwaukee, WI; Paul Scott, M.D.),Medical University of South Carolina (Charleston, SC; Julio Barredo,M.D.), North Shore-Long Island Hospital; Banu Aygun, M.D.),SUNY-Downstate Medical Center (New York, NY; Scott Miller, M.D.),University of Alabama at Birmingham (Birmingham, AL; Lee Hilliard,M.D.), University of Miami (Miami, FL; Ofelia Alvarez, M.D.),University of Mississippi Medical Center (Jackson, MS; Rathi Iyer,M.D.), University of Texas Southwestern (Dallas, TX; Zora Rogers,M.D.), Wayne State University (Detroit, MI; Sharada Sarnaik, M.D.).

St. Jude Children's Research Hospital
St. Jude Children's Research Hospital is internationally recognized forits pioneering work in finding cures and saving children with cancerand other catastrophic diseases. Founded by late entertainer DannyThomas and based in Memphis, Tenn., St. Jude freely shares itsdiscoveries with scientific and medical communities around the world.No family ever pays for treatments not covered by insurance, andfamilies without insurance are never asked to pay. St. Jude isfinancially supported by ALSAC, its fund-raising organization. For moreinformation, please visit www.stjude.org.