Minihaplo-BMT can cure severe hemoglobinopathies

Four of the 5 beta-thalassemia patients achieved full donor chimerism, and 1 had mixed chimerism. All 5 patients became transfusion-independent.

Eleven of the 12 SCD patients engrafted, and 9 achieved full donor chimerism.

All but one of the engrafted SCD patients became transfusion-independent. The exception was a mixed chimeric patient who had a major ABO mismatched donor. The patient remains transfusion-dependent more than 30 months after BMT.

“This is the main problem we have seen in all our sickle cell and hemoglobinopathy experiences,” Dr Bolaños-Meade said. “If you have a major ABO incompatibility, and there’s mixed chimerism, you’re asking for trouble.”

Toxicity

All SCD patients had sickle cell crises after antithymocyte globulin. Other toxicities included sirolimus-induced diabetes in 1 patient, worsening of Meniere’s disease in 1 patient, and BK cystitis in 1 patient.

Two patients developed grade 2 acute GVHD, and 1 developed grade 3 acute GVHD. Three patients had chronic GVHD, 2 mild and 1 moderate.

However, all cases of GVHD resolved. And, of the 8 engrafted patients with more than 1 year of follow-up, 6 are off systemic immunosuppression.