It’s not very often that a researcher is involved in the discovery of a new medical treatment that dramatically improves patient survival rates and attracts worldwide attention.
In fact, BC Children's Hospital pediatric haematologist and oncologist Dr. Kirk Schultz calls the discovery of a new treatment for childhood leukemia the “home run” of his career as a clinical researcher.
Schultz was the leader of a North America-wide clinical trial to explore the effectiveness of imatinib, a new generation “targeted” drug, in treating Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ALL), a particularly difficult type of leukemia that affects about one child in BC every year. Targeted drugs attack specific molecules on cancer cells, unlike chemotherapy which kills all rapidly dividing cells in the patient’s body.
The five-year survival rate for children with Ph+ALL treated with conventional chemotherapy is less than 30 percent, while bone marrow transplantation achieves a 60 percent rate of success, but is associated with toxic side effects. In the clinical trial however, combining intensive chemotherapy with imatinib was shown to provide a cure for 87 percent of children with this leukemia.
“I have to say I was very surprised by the results,” says Schultz. “It’s what every research doctor wants to see, and it’s likely the only time in my career that this will happen.”
- A difficult-to-treat type of leukemia that occurs among 3% of children with leukemia
- Affects about one child a year in BC
- Previously the best treatment option was bone marrow transplant, with much higher toxic side effects
Because PH+ALL only occurs in three percent of children with leukemia, to ensure statistical significance the imatinib clinical trial involved patients from 20 different cancer centres across the continent, including a young boy from Chilliwack.
Schultz says studies are now underway to test the effectiveness of other next-generation targeted drugs similar to imatinib, and to explore treatment for adults, among whom PH+ALL occurs much more frequently than for children.
Dr. Kirk Schultz is Director of the Michael Cuccione Childhood Cancer Research Program at BC Children's Hospital, Head of the Childhood Cancer & Blood Research Group and Professor in the Division of Hematology and Oncology in the Department of Pediatrics at UBC.
National Cancer Institute / National Institutes of Health