Activity and safety of combination chemotherapy with methotrexate, ifosfamide, l-asparaginase and dexamethasone (MILD) for refractory lymphoid malignancies: a pilot study.

Optimal salvage chemotherapy has not been established for lymphoid malignancy, which is refractory to the conventional cyclophosphamide, doxorubicin, vincristine, and prednisone regimen. To explore an effective regimen, we conducted a phase I pilot study of combination chemotherapy with methotrexate, ifosfamide, l-asparaginase and dexamethasone (MILD), which are unaffected by MDR1-encoded P-glycoprotein. A total of 18 patients with lethal lymphoid malignancy were enrolled over a 2-yr period. The median age was 63 yr. Eleven patients had T/NK-cell malignancies, six had B-cell malignancies, and one was diagnosed with a blastic plasmacytoid dendritic cell neoplasm. Patients aged >/=60 and <60 yr were planned to receive a set of starting doses of methotrexate and ifosfamide, which should induce myelosuppression. Eleven patients completed two courses of MILD therapy. Treatment-related death because of systemic mucormycosis was observed in one patient. Major treatment-related adverse events were grade 3 or more hematologic toxicities, which included lymphopenia corresponding to dose-limiting toxicity. The most common grade 3 non-hematologic toxicity was febrile neutropenia. Of the 14 evaluated patients, three achieved a complete response, and four showed a partial response. The overall response rate was 57%. It was very interesting that all of seven responders had T/NK-cell malignancies. MILD therapy was feasible and presented acceptable toxicity in patients with refractory or lethal lymphoid malignancies. The efficacy for T/NK-cell malignancies should be further evaluated.