Patients with Langerhans cell histiocytosis (LCH) may behave differently depending on what sites are involved and the response or lack of response to earlier therapies. Therapy for high-risk patients or those with multiple reactivations continues to be challenging because of variable response rates and frequent toxicities. The goals of this study were to determine the long-term disease free survival in children with high-risk or multiply reactivated LCH treated with 2-CDA, and the toxicity of low dose continuous infusion (CI). Ten children with multiple reactivations or high-risk disease as defined by the Histiocyte Society were treated with CI 2-CDA and were evaluable for response and toxicity assessment. The starting dose of 2-CDA was 5 mg/M(2)/day for 3 days and escalated to 6.5 mg/M(2)/day for 3 days if tolerated. The maximum number of courses of 2-CDA per patient was limited to six. Fifty-two courses of 2-CDA were administered without difficulty. After the patient demonstrated no acute toxicity with the first administration of 2-CDA, the subsequent doses were given at home to all but one patient. All 10 patients had a clinical response, 9 documented by radiographic, or changes in physical exam or review of systems. Toxicity was limited to myelosuppression. Seven of the 10 patients required no additional therapy and remain disease free a median of 50 months from completing therapy. The three remaining patients are currently disease free after receiving other therapy. Further studies are needed to determine the role of 2-CDA in this patient population. 2-CDA can be given safely using home therapy, and may effective even in high-risk patients.
Copyright 2004 Wiley-Liss, Inc.