Ruxolitinib in children with steroid-refractory acute graft-versus-host disease: A retrospective multicenter study of the pediatric group of SFGM-TC

BACKGROUND

We conducted a national multicenter retrospective study in France to evaluate the efficacy and tolerance of ruxolitinib in children with steroid-refractory acute graft-versus-host disease (aGVHD) after allogeneic hematopoietic stem cell transplant.

PROCEDURE

Patients were recruited from the 15 pediatric transplantation centers. Transplanted patients were eligible if they met the following criteria: aged ≤ 18 years at transplantation, receiving a myeloablative allogeneic hematopoietic stem cell transplant, having an aGVHD of grade ≥2, and treated with ruxolitinib for steroid-refractory aGVHD.

RESULTS

Twenty-nine patients received ruxolitinib for steroid-refractory aGVHD. Six patients achieved a complete response at day 28 after the start of treatment but finally 19 patients (65.5%) achieved a complete response (CR) with a median delay of 41 days (5-93 days). Two patients had a partial response. All patients who achieved CR or partial response discontinued corticosteroid treatment. Eight patients showed treatment failure. The overall response rate was 72.4%. Twenty-three of 29 patients were alive at a median follow-up of 685 days (177-1042 days) after the hematopoietic stem cell transplantation. Viral replication was observed in 41.4% of cases. We did not observe severe hematological adverse events and cytopenia requiring a modification of ruxolitinib doses always resolved. The median initial dose of ruxolitinib was 12.6 mg/m² /day with an important range. We could not demonstrate any relationship between initial dose and effectiveness.

CONCLUSION

Ruxolitinib may constitute a promising second-line treatment for children with steroid-refractory aGVHD that should be validated in a prospective large-scale pharmacokinetic and efficacy trial.

Immunological effects in patients with steroid-refractory graft-versus-host disease following treatment with basiliximab, a CD25 monoclonal antibody

Steroid-refractory graft-versus-host disease (GvHD) is a complication following an allogeneic stem cell transplantation with limited therapeutic options. Studies have shown a response in up to 80% of patients with this condition after treatment with the CD25 monoclonal antibody, basiliximab. Despite the good responses to treatment, around 50% of the patients experience recurrence of their GvHD symptoms 4-6 wk following cessation of therapy. The in vivo changes in the following treatment with this antibody have not been elucidated so far. We treated 14 patients with severe steroid-refractory GvHD with basiliximab weekly for 4 wk and monitored the changes in the T-, B-, NK- and dendritic cell subsets over this time period. The overall response to treatment was 92% (13/14) with 50% (7/14) achieving a complete response. Fifty four percentage (7/13) of the patients who responded showed recurrence of their GvHD symptoms. Contrary to expectations, our observations showed a significant depletion of the regulatory T-cell subset following treatment. Our findings suggest that the undesirable depletion of the regulatory T cells along with the CD25(+) acute inflammatory cells might be responsible for the high incidence of GvHD recurrence in this cohort of patients.