Doubling the dose of total-body irradiation (TBI) led to a near-doubling of the engraftment rate for patients with severe hemoglobinopathies undergoing haploidentical transplants, a small clinical trial showed.
All but one of 17 patients had successful engraftment after receiving 400 cGy TBI as part of a nonmyeloablative conditioning regimen. Following successful engraftment, 15 of 16 patients remained transfusion independent, and 14 of 16 discontinued immunosuppression.
Four patients developed grade 2 acute graft-versus-host disease (GVHD) and one developed grade 3, but GVHD had resolved in all cases at the most recent follow-up, Javier Bolaños-Meade, MD, of Johns Hopkins Sidney Kimmel Comprehensive Cancer Center in Baltimore, and co-authors reported online in The Lancet Haematology.