Treatment Protocol of the Third International Study For Langerhans Cell Histiocytosis

OBJECTIVES:

Primary

• Compare the efficacy, in terms of response to initial therapy, of prednisolone, vinblastine, and mercaptopurine with vs without methotrexate and leucovorin calcium in young patients with Langerhans cell histiocytosis.
• Compare the progression-free survival of patients with low-risk Langerhans cell histiocytosis who responded to initial therapy who are then treated with 6-month vs 12-month continuation therapy comprising prednisolone and vinblastine.

Secondary

• Compare the acute and long-term toxicity and the incidence of permanent effects.
• Compare the overall and progression-free survival, response rate, and time until response.