Growing cord blood stem cells in a laboratory before transplanting them into patients with leukemia, lymphoma, and other blood cancers significantly improves survival, according to a new study. It was presented at the American Society of Hematology (ASH) meeting, held December 7-10, 2013, in New Orleans, Louisiana.
A cord blood donation contains only about one ounce of blood, which usually is enough for only a child or very small adult. Many adults, therefore, receive a double dose of cord blood stem cells donated by two newborns.
The study examined a new technology called StemEx (Gamida Cell Ltd., Jerusalem, Israel), which grows cord blood stem cells in an outside laboratory. After 21 days, there’s a roughly 14-fold increase in the number of stem cells available for transplant.
The study included 25 centers in the United States, Europe, and Israel. Researchers used the StemEx technology for cord blood transplants in 101 leukemia and lymphoma patients. These patients were compared with a historical control group of 295 patients who each received a double dose of cord blood stem cells.
After 100 days, the overall survival was significantly higher in the StemEx group (84.2%) than in the control group (74.6%). The StemEx transplants also were quicker to engraft (ie, develop into a sufficient number of blood cells). In the StemEx group, engraftment of neutrophil blood cells took a median of 21 days, compared with 28 days in the control group. Engraftment of platelets took a median of 54 days in the StemEx group and 105 days in the control group. (Neutrophils are infection-fighting white blood cells; platelets are small blood components that help the clotting process.) The faster the neutrophils and platelets are engrafted, the less time patients are vulnerable to infections and bleeding.
Kathy Boltz, PhD