L-DEP regimen salvage therapy for paediatric patients with refractory Epstein-Barr virus-associated haemophagocytic lymphohistiocytosis.

Epstein-Barr virus-associated haemophagocytic lymphohistiocytosis (EBV-HLH) is one of the most common subtypes of secondary HLH. However, more than 30% of patients do not respond to traditional treatment. Here, we investigated the efficacy and safety of the L-DEP regimen as a salvage therapy for paediatric refractory EBV-HLH. We retrospectively analysed 26 paediatric patients with refractory EBV-HLH who received the L-DEP regimen at Beijing Children's Hospital from 1 January 2016 to 31 March 2019. Five of the patients achieved complete response (CR) and 11 achieved partial response (PR), indicating an overall response rate of 61·5% (CR + PR). Ten of the 16 patients who achieved CR or PR received allogenic haematopoietic stem cell transplantation (allo-HSCT), and seven were still alive at the last follow-up on 30 April 2020. Two of the 10 patients who did not respond were alive after allo-HSCT. Major side effects included increased amylase, bone marrow suppression and coagulation disorders, though these could be controlled by supportive therapy in most cases. Thus, we conclude that the L-DEP regimen is an effective and relatively safe salvage therapy for children with refractory EBV-HLH. This regimen also provides a bridge to allo-HSCT.