May 17, 2002 -- People who suffer from sickle cell disease may find relief from an experimental drug used to treat cancer patients. A clinical trial shows that decitabine works in sickle cell patients -- even those who don't respond to standard sickle cell treatments -- and produces fewer side effects.
The study is published in the June 1 issue of the journal Blood.
Although it can affect anyone, sickle cell anemia is most common in people of African descent -- about one in 500 black people suffers from the disease. It is caused by an inherited genetic mutation of the red blood cells that affects how the body creates hemoglobin -- the substance in the cells that supplies oxygen to cells throughout the body. The defective hemoglobin (called hemoglobin S) causes the red blood cells to take on a crescent or sickle shape and reduces their ability to carry oxygen where it's needed.
These abnormal red blood cells multiply faster than normal red blood cells. But a type of hemoglobin produced in the fetus, which normally disappears by age 1, can slow down the changes in hemoglobin S that cause the red blood cells to become deformed. Standard therapies for sickle cell disease strive to increase the body's production of this fetal hemoglobin to reduce these effects, which also combats the painful symptoms of the disease.
In the study, eight patients who had not responded to the standard drug for sickle cell treatment, hydroxyurea, received the cancer drug. Decitabine was delivered directly into the patients' veins five days a week for two weeks, followed by a four-week observation period. The same cycle was repeated, with adjusted doses, over a nine-month period.
Decitabine is still experimental and not yet available to the public.
At the end of the study, the therapy had succeeded in maintaining fetal hemoglobin levels at close to 20% of all hemoglobin in the patient's blood -- a level considered optimal for sickle cell treatment and reduction of symptoms.
And unlike hydroxyurea, which causes a decline in the production of all types of blood cells, the study showed decitabine only caused a slight drop in infection-fighting blood cells. No decreases were found for other types of blood cells.
"The results of our study are compelling," says study author Joseph DeSimone, PhD, professor of hematology and oncology at the University of Illinois at Chicago, in a news release. "Clearly, decitabine is an effective therapy for patients who do not benefit from the traditional treatment. It is possibly even an improvement, although more studies will have to be done."
Decitabine manufacturer SuperGen Inc. partially funded this study.