2-Chlorodeoxyadenosine for Children with Recurrent or Refractory Langerhans Cell Histiocytosis

Yoon, Hoi Kyung; Kook, Hoon; Kim, So Youn; Choi, Ik Sun; Kim, Seok Joo; Sohn, Kyoung Ran; Han, Dong Kyun; Noh, Ha Young; Choi, Jin Soo; Hwang, Tai Ju

Abstract

PURPOSE
Langerhans cell histiocytosis (LCH) is a disorder characterized by the proliferation of activated Langerhans cells. Although current therapies are very effective at inducing remission, multiple recurrences and long-term sequelae are common for young patients. For this reason, more effective therapies based on the pathogenesis of LCH are needed. We investigated the use of 2-chlorodeoxyadenosine (2-CdA), a purine analogue with an antiproliferative effect on histiocytes and lymphocytes, in patients with recurrent or refractory LCH. METHODS: Four children with recurrent or refractory LCH received 2-CdA (5~7 mg/m2/day for 5 days, given as a 24-hr continuous infusion and repeated every 21~28 days for 5~7 courses). RESULTS: All four patients had multiorgan involvement, and were heavily pretreated. Of the two children with recurrent diseases, one had complete response and the other showed no active disease except for the remaining diabetes insipidus. Two infants who showed poor early response to previous combination chemotherapy also responded poorly: partial response in one, and progressive disease resulting in death in the other. Toxicity consisted mainly of myelosuppression, but significant infections did not occur. The peripheral neuropathy was not seen. CONCLUSION: 2-CdA, tolerable in children without significant side effects, might be effective for the treatment of recurrent LCH in children. However, the efficacy in infants with multi-system, refractory diseases needs further study. The feasibility of 2-CdA treatment as the first-line therapy for high-risk diseases, and the possibility of combination with other agents needs to be addressed in the future.