Updates on Pediatric Leukemia Research

Jennifer Gershman, PharmD, CPh

Researchers are making progress in identifying drugs that target certain mutations.

Leukemia is the most common type of pediatric cancer, accounting for almost 1 out of 3 cancers diagnosed in children. Most pediatric leukemias are acute lymphoblastic leukemia (ALL), which sis sometimes called acute lymphocytic leukemia. Most of remaining cases are acute myeloid leukemia (AML). Both ALL and AML are forms of cancer that progress rapidly and require immediate treatment. Standard pediatric leukemia treatments generally involve chemotherapy, radiation therapy, and stem-cell transplant.Research is now focusing on targeted drugs, immunotherapies and newer chemotherapy drugs.

Targeted drugs

Approximately 10% of children with AML have changes in the gene called FLT3, and a phase 3 randomized trial is currently underway to evaluate Nexavar (sorafenib), which targets FLT3, in addition to standard chemotherapy in patients with newly diagnosed AML. Some pediatric leukemias also have gene fusions that can increase cancer cell growth.Vitrakvi (larotrectinib) is currently approved for adult and pediatric patients with solid tumors that have a NTRK gene fusion. Another drug, larotrectinib, is currently being studied in children with leukemia that have a NTRK gene fusion. The Pediatric Preclinical Testing Consortium is also addressing challenges associated with developing new targeted therapies for children by providing reliable preclinical data to lay the foundation for robust clinical trials.

Immunotherapies

Researchers recently identified a new immunotherapy treatment target known as mesothelin (MSLN) for AML in pediatric patients. A study of mesothelin that was recently published in Blood Advances involved genomic data obtained from over 2,000 children and young adults with AML. The researchers compared that data to similar data from individuals with normal bone marrow. The study found that MSLN was expressed in 36% of study participants with AML. Next, the researchers selected new immunotherapy drugs that would target MSLN to test in cell-lines and animal models to estimate pre-clinical efficacy of leukemia treatments. Two investigational immunotherapies, anetumab ravtansine and a new compound, anti-MSLN-DGN462, produced potent destruction of leukemia cells in both lab testing and mouse models. "

"Using genomic sequencing data, we identified novel targets for children’s cancer and worked with collaborators to engineer new therapies for children with AML, rather than repurpose drugs from the adult cancer realm that don’t work well in children,” said E. Anders Kolb, M.D., director of Nemours Center for Childhood Cancer Research and a study author, in a press release.Further research is needed for this promising new immunotherapy treatment target.

Chemotherapies

Researchers are working to develop new chemotherapy drugs for leukemia and are evaluating current medications to find better ways to utilize existing drugs. Venclexta (venetoclax) is FDA approved in adults with certain leukemias, and it is now being studied in children with AML that did not respond to previous treatments or have relapsed.