To mark International Childhood Cancer Day, the Centre de recherche Azrieli du CHU Sainte-Justine is proud to announce the launch of a randomized clinical trial to demonstrate the efficacy of a combination therapy for children with acute lymphoblastic leukemia (ALL). Led by Dr. Thai Hoa Tran, pediatric hematologist/oncologist and clinician-researcher at CHU Sainte-Justine, as part of the Children’s Oncology Group (COG), the Phase 3 trial will investigate a new combination of immunotherapy with targeted therapy and chemotherapy for Philadelphia chromosome-positive or Philadelphia-like ALL. It will begin in April 2024 in the United States, followed by Canada, Australia, New Zealand and 17 European countries. 

Targeted treatment: more effective and less toxic

ALL is the most common cancer in children. New advances in genomics have led to the discovery of new subtypes of ALL, including one involving the Philadelphia chromosome (LAL Phi+) and another very similar subtype known as “Philadelphia-like” (Phi-like ALL), discovered in 2009. These are rare forms of leukemia, accounting for 5–10% of pediatric ALL cases, but are often very aggressive.

According to Dr. Tran, “The cells in these types of leukemia are often more resistant to conventional chemotherapy, and relapses occur earlier and more frequently. They used to be treated with the most intensive chemotherapy regimens, often with bone marrow transplants. But these aggressive treatments are associated with many unwanted short- and long-term side effects.” 

Dr. Tran’s new clinical trial proposes to combine immunotherapy (blinatumomab) with targeted therapy (dasatinib) to replace some of the more toxic chemotherapy blocks. This new approach aims to reduce the side effects associated with conventional chemotherapy while maintaining sustained remission rates with the introduction of immunotherapy and targeted therapy earlier in the course of treatment. Already shown to be effective for adults, this strategy is designed to reduce relapse rates and treatment toxicities and to improve quality of life for patients.

International collaboration – A new paradigm for rare leukemias

After more than five years of hard work, this clinical trial led by Dr. Tran and funded by the U.S. National Cancer Institute is the result of an international partnership between the three largest pediatric oncology consortia in the world. “International collaborations are now vital to improving the treatment of ‘orphan’ diseases. They make it possible to quickly recruit enough patients for randomized trials that will set new standards of treatment for these rare types of ALL, which still have suboptimal prognoses.” This study will involve 680 patients over four years and will be available in over 20 countries worldwide, including around 200 institutions in North America and over 150 centres in Europe.

Together, these collaborative efforts are providing faster access to innovative treatments and a brighter future for children with leukemia and their families.

From left to right: Mélanie Sagniez, Marieke Rozendaal, Dr Thai Hoa Tran and Louise Laramée © CHU Sainte-Justine (Véronique Lavoie)