Boston Children's Hospital has announced a $1.5 million grant from the Bill & Melinda Gates Foundation to develop more efficient gene therapy treatments for sickle cell disease and introduce those therapies in regions of the world with high rates of sickle cell disease.

Gene therapy delivers genetic material into a patient's cells to replace faulty or missing genes — or add new genes — in an attempt to cure disease or make changes so the body is better able to fight off disease. The collaboration between Boston Children's, the Koch Institute, Dana-Farber Cancer Institute, the Whitehead Institute, and Massachusetts General Hospital will focus on adapting methods used in Dana-Farber/Boston Children's current gene therapy trial for sickle cell disease, which suppresses a gene called BCL11A, enabling patients to make a fetal, non-sickling form of hemoglobin.

Like several other gene therapies for sickle cell, the therapy in trials at Boston Children's/Dana Farber is ex vivo — meaning it involves removing blood stem cells from the body, treating them with a gene therapy vector, and then infusing the cells back into the patient. It is an approach, however, that involves multiple complicated manufacturing steps, takes weeks to complete, and requires significant hospitalization. In vivo gene therapy, in contrast, involves direct injection of the gene therapy vector, carrying the desired gene into the bloodstream or target organ. The goal going forward is to develop methods that allow in vivo gene therapy applications for sickle cell disease in areas of the world where health care is less developed than in the United States or Europe.

"Ultimately, an in vivo approach, in which a gene or inhibitory RNA is delivered directly to the body, is likely to be optimal for broadening gene access," said David A. Williams, chief scientific officer and senior vice president of Boston Children's Hospital and president of Dana-Farber/Boston Children's Cancer and Blood Disorders Center. "Our vision is to apply our expertise in bioengineering and vector technology, hematology, and stem cell engraftment with minimal marrow conditioning and closed and simplified manufacturing to 'commoditize' gene therapy."