Ruxolitinib Reduces Posttransplant GVHD Risk in Pediatric β-Thalassemia Major

Ruxolitinib (Jakafi) may be a meaningful prophylactic against graft-versus-host disease (GVHD) in children with β-thalassemia major who undergo allogeneic hematopoietic stem cell transplantation (allo-HSCT), according to a new report.

The study was published in Pediatric Transplantation.

Allo-HSCT is the only curative treatment for people with β-thalassemia major, noted the study authors. In cases where a human leukocyte antigen (HLA)-matched sibling donor is available, posttransplant survival is above 90% and transplant-related mortality is less than 10%, they noted.

However, roughly half of patients do not have an available HLA-matched donor. In those cases, the 3-year survival rate is 85% to 90%, and the risk of GVHD is notably higher, the authors said.

“Up to 50% of pediatric patients suffer from GVHD after allo-HSCT, and 10% to 20% develop severe GVHD,” they wrote.

The Janus kinase (JAK) inhibitor ruxolitinib is a known effective treatment for GVHD, but emerging evidence suggests it might also be an effective prophylactic to prevent the complication. To date, however, the authors said the few studies looking at ruxolitinib in patients with pediatric thalassemia have focused on treating rather than preventing GVHD.

They decided to retrospectively analyze 49 cases of pediatric β-thalassemia major in which patients underwent HSCT from unrelated or haploidentical donors to see whether the addition of ruxolitinib to patients’ prophylaxis regimens improved outcomes. All transplants occurred between February 2018 and October 2022.

All of the patients in the study received cyclosporine A, mycophenolate mofetil, and short-term methotrexate as prophylaxis; 27 patients also received 2.5 mg of ruxolitinib twice daily.

The investigators found that ruxolitinib made a significant difference in the rates of GVHD. The incidence of acute GVHD was 22.2% in the ruxolitinib group compared with 40.9% in the control group (P = .153). Chronic GVHD incidence was 18.5% in the ruxolitinib group vs 40.9% in the control group (P = .072). There were no cases of grade 3/4 acute GVHD in the ruxolitinib group, but 27.3% of patients in the control group experienced the complication (P = 0.005).

The authors also found a survival advantage for patients receiving ruxolitinib. These patients had 2-year overall survival (OS) and thalassemia-free survival rates of 96.3% compared with 90.1% OF and thalassemia-free survival rates. Two patients in the control group died from acute intestinal GVHD. The investigators found that rates of Epstein-Barr/cytomegalovirus reactivation and BK virus infection were similar between the groups.

They said their findings were limited by the study’s retrospective nature, its small sample size, and the fact that it was a single-center study. They also said it is not clear what the optimal dose of prophylactic ruxolitinib should be for pediatric patients. The investigators chose their dosing based on previous studies that found doses of 5 mg/day or higher were safe and effective in pediatric patients. In the new study, no adverse events or hematological toxicities were reported.

Although the authors said their findings had significant limitations, they said the results offer positive indications that ruxolitinib might be a helpful part of GVHD prophylaxis.

“This study provides a basis for the analysis of JAK inhibitors in the prevention and treatment of GVHD and contributes toward alternative transplantation strategies for β-thalassemia major pediatric patients,” they concluded.

Reference

Hong X, Chen Y, Lu J, Lu Q. Addition of ruxolitinib in graft-versus-host disease prophylaxis for pediatric β-thalassemia major patients after allogeneic stem cell transplantation: a retrospective cohort study. Pediatr Transplant. 2023;27(2):e14466. doi:10.1111/petr.14466