Bone Marrow Transplant May Be Safe, Cost-Effective Treatment for Sickle Cell Disease

March 05, 2025

A novel bone marrow transplant (BMT) approach offers a safe and curative treatment for adults with sickle cell disease (SCD) and may provide a more affordable alternative to gene therapy, according to research published Feb. 25 in NEJM Evidence.

The phase 2 trial evaluated a reduced intensity haploidentical BMT protocol co-developed by researchers at the Johns Hopkins Kimmel Cancer Center, the University of California San Francisco and Vanderbilt University Medical Center. The study builds on prior research from Vanderbilt-led Global Haploidentical BMT Learning Collaborative, which published findings on the feasibility of reduced-intensity haploidentical BMT for SCD in Blood last year.

The approach uses a “half-matched” donor related to the patient and a conditioning regimen of low-dose chemotherapy and total body irradiation. After transplantation, patients receive cyclophosphamide and other immunosuppressive drugs to prevent graft-versus-host disease (GVHD).

In this study, 95% of the 42 trial participants were alive at two years post-transplant, and 88% were considered cured, living without disease-related events. The incidence of severe acute GVHD was 4.8%, while 22.4% of patients developed chronic GVHD. Three patients experienced primary or secondary graft failure, and four died during the study period, including two from infectious complications.

A More Affordable Path to a Cure

The findings suggest that reduced-intensity haploidentical BMT could be a significantly less expensive and more accessible SCD cure than gene therapy. Richard Jones, MD, a study co-author, noted that transplant outcomes were comparable to or better than those reported for gene therapy.

“Our results with allogeneic transplant are every bit as good as or better than what you see with gene therapy,” Jones said.

In a separate analysis published in Blood Advances, Jones and co-authors Adetola A. Kassim, MD, MS; Robert A. Brodsky, MD; and Michael R. DeBaun, MD, MPH, examined the financial and logistical burden of gene therapy. They noted that gene therapy for SCD typically requires prolonged hospitalization and numerous transfusions, with an estimated cost of $2 million to $3 million per patient. In contrast, the median number of transfusions following haploidentical BMT was six, and most of the procedure was managed on an outpatient basis at a cost of approximately $467,747.

According to the investigators, in addition to confirming BMT as a lower-cost treatment for SCD, the findings also challenge the perception that successful transplantation for SCD requires a fully matched donor and carries excessive risk. They anticipate publishing results from a similar study in a pediatric population later this year.