Purpose: The Southwest Oncology Group performed a Phase II study to investigate the effectiveness of an induction regimen of high dose cytosine arabinoside (ara-C) with high dose mitoxantrone for treatment of relapsed or refractory adult acute lymphoblastic leukemia (ALL).
Patients and methods: Patients at least 16-years-old with ALL that was in relapse after, or was refractory to, standard induction therapy including at least vincristine and prednisone were eligible, as long as they had no prior treatment with high dose ara-C. The induction regimen included high dose ara-C (3 g/m2 by 3-h i.v. days 1-5) and mitoxantrone (80 mg/m2 by 15-30 min i.v. 12-20 h after the first dose of ara-C). The study design called for a maximum of 55 patients, with early termination if less than nine of the first 30 achieved complete remission.
Results: Thirty-three patients entered the study, and 31 were included in the analysis. All 31 completed one course of induction therapy. Four patients died of infection and a fifth of cardiomyopathy with possible sepsis. Seven patients achieved complete remission (23%; 95% confidence interval 10-41%). One of the seven received syngeneic bone marrow transplantation while in remission, and the other six all relapsed within 10 months. All 31 patients died within 25 months after entering the study.
Conclusions: The regimen of high dose ara-C and mitoxantrone was found to be insufficiently effective to warrant further investigation.