New research may yield more effective treatment for childhood leukemia

Jan 6 2010

A team of Israeli scientists at the Sheba Medical Center's Research Center for Leukemia and Childhood Malignancies has discovered a method for developing a more effective and less perilous treatment for those suffering from childhood leukemia, the most common cancer in children. New treatments associated with the research have the potential to impact upwards of 20 percent of those suffering from Acute Lymphoblastic Leukemia (ALL).

The team, led by Dr. Shai Izraeli, who worked in partnership with scientists at Tel Aviv University and the International BFM Study Group, has published a series of papers examining certain gene abnormalities in children with Down syndrome, which are 20-30 times more likely to develop ALL.

"Our research gives hope to a substantial portion of the children who might be taken by this horrible disease," Izraeli said.

In the most recent paper, published in the leading hematology journal Blood, the researchers found that a gene abnormality called CLRF2 is common in more than 60% of ALL patients with Down syndrome. What makes this finding so significant is that the abnormality is directly connected to an anomalous protein, JAK2, which stimulates the kind of disruptive cell behavior typical of leukemia. Importantly, these abnormalities, which have now also been examined and reported by several research groups in the US and Europe, also appear in the leukemia cells of some children and adults without Down syndrome as well.

The findings indicate that using drugs to block the activity of anomalous JAK2 can effectively treat blood cells transformed by the abnormality. This targeted approach is likely to be more precise and less toxic than chemotherapy.

Currently, children with leukemia, receive intensive chemotherapy over two to three years, and about eight out of 10 recover. But chemotherapy is highly toxic, and does not target the specific abnormality underlying the disease. Treatments associated with this research would be able to address these issues, and importantly the drugs already exist.

Drugs targeting the JAK2 protein are currently in clinical trials - but for a different blood disorder (polycythemia vera). Thus, if preclinical and then clinical trials in those suffering from ALL confirm Izraeli's findings, no new drug need be developed - often a task that can take more than a decade to complete.

Using these existing drugs as a basis, Izraeli and his team are confident that more powerful and safer leukemia drugs for children are only a few years away. "We will know in just a few years specifically what these drugs are capable of, but the research conducted thus far gives me great hope," Izraeli said.

"The breakthroughs we've achieved were made possible by the advantages of our location within the Sheba Medical Center; specifically its proximity to the patients and to the most advanced state-of-the-art research infrastructure which together allow us to quickly translate questions arising from observations in patients to laboratory research," Izraeli said..

SOURCE Sheba Medical Center