Novel conditioning and familial haploidentical SCT well tolerated, cured 90% of patients



– A novel myeloablative regimen along with familial haploidentical stem cell transplantation was well tolerated and cured 90% of 19 young patients with high-risk sickle cell disease who underwent the procedure, according to Mitchell S. Cairo, MD.

The approach involved parental donors who were partial matches (as opposed to human leukocyte antigen [HLA]–matched sibling donors), CD34 enrichment, and mononuclear cell add-back (2 x 105 CD3/kg). The treatment resulted in a low cumulative incidence of acute and chronic graft-versus-host disease (6.2% and 6.7%, respectively) and stable to improved pulmonary and cardiac function. Patients also experienced significantly improved neurocognition and health-related quality of life at 2-year follow-up, Dr. Cairo of New York Medical College, Valhalla, reported at the annual meeting of the American Society of Hematology.

In a video interview, Dr. Cairo described the study, the potential benefits of familial haploidentical transplantation, and future directions.

“We have a 1-year 90% survival rate, and ... with a median follow-up now of 3 years with this approach, no patient has signs or symptoms of sickle cell disease,” he said. While the standard of care is “still to use an HLA-matched sibling donor that doesn’t have sickle cell disease,” this novel approach could benefit the five of six patients who don’t have such a donor.

The risks appear similar with the two approaches, but “more numbers will be needed to confirm this preliminary finding,” he said.

A second Food and Drug Administration–supported study with patients aged up to age 35 years (vs. 21 years in the current study) and with lower doses of the conditioning regimen to potentially reduce the risk of late adverse effects is underway, he said.

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