Sustaining integrating imatinib and interferon-α into maintenance therapy improves survival of patients with Philadelphia positive acute lymphoblastic leukemia ineligible for allogeneic stem cell transplantation

We report the clinical results of sustainedly integrating imatinib and interferon-alpha into maintenance therapy in the patients ineligible for allogeneic hematopoietic stem cell transplantation (allo-HSCT). Maintenance therapy lasted for 5 years with imatinib 400mg daily, interferon-alpha 3 million units, 2 similar to 3 doses per week, and chemotherapy including vindesine and dexamethasone scheduled monthly in first year, once every 2 months in second year, and once every 3 months in third year. The chemotherapy was discontinued after 3 years and the imatinib and interferon-alpha continued for another 2 years. For 41 patients without allo-HSCT with a median follow-up of 32 months, the 3-year DFS and OS were 42.7 +/- 8.6% and 57.9 +/- 8.4%, respectively. Our study suggests that sustaining maintenance with low-dose chemotherapy, imatinib and interferon-alpha improved survival of adult Philadelphia-positive acute lymphoblastic leukemia (Ph + ALL) patients ineligible for allo-HSCT, and even provided an opportunity for cure. BCR/ABL persistent negativity at 6 and 9 months may have benefit to choose suitable patients for the imatinib/interferon-alpha maintenance strategy.