In a phase I study, tumors shrank or disappeared and disease progression was temporarily halted in 15 children with advanced neuroblastoma enrolled in a safety study of an experimental antibody produced at St. Jude Children’s Research Hospital.
Four patients are still alive after more than two-and-a-half years and without additional treatment. Findings from the phase I study were published in the Journal of Clinical Oncology.
The results prompted St. Jude to expand clinical trials of the monoclonal antibody hu14.18K322A to include patients newly diagnosed with neuroblastoma. Monoclonal antibodies are engineered in the laboratory to recognize and attach to specific markers carried on the cell surface.
In the study, 38 patients received one of nine different doses of hu14.18K322A. The immunotherapy is designed to activate the immune system to attack and kill tumor cells. Every 28 days, patients received an infusion of hu14.18K322A once daily for four days.
Of the 31 patients evaluated after two or more rounds of treatment, the disease stabilized in nine patients, tumors shrank in two patients and were undetectable in four more, researchers reported.
Hu14.18K322A is engineered to attach to the GD2 antigen, found on the surface of almost all neuroblastoma cells as well as other tumors, including the skin cancer melanoma, the bone cancer osteosarcoma and soft-tissue sarcomas. The antigen is found on the normal cells of just a few tissues.
The monoclonal antibody in this study is one of several antibodies targeting GD2 that are in clinical development for treatment of neuroblastoma.
In this study, pain remained the most common side effect associated with hu14.18K322A treatment. While 68 percent of patients reported severe pain during the first round of treatment, Navid said the pain was manageable with medication and resolved within 24 hours of receiving the experimental antibody. The pain also lessened with each round of therapy.
Clinical trials involving hu14.18K322A continue at St. Jude. Researchers are testing the impact of giving the monoclonal antibody weekly rather than every 28 days and in combination with other therapies.
