Alpha-interferon improves survival and remission duration in P-190(BCR-ABL) positive adult acute lymphoblastic leukemia

Treatment of P190(BCR-ABL+) acute lymphoblastic leukemia (ALL) patients rem ains problematic: one possibility is to use biologic response modifiers suc h as alpha-interferon (alpha-IFN), which is known to be active in chronic m yeloid leukemia (CML), We used alpha-IFN to treat 10 adult p190(BCR-ABL+) A LL patients (eight newly diagnosed; two in first relapse). All received a r emission induction chemotherapy (modified L-20 protocol), Patients achievin g morphological, immunological and cytogenetic complete remission (CR) were then submitted to a rotational consolidation regimen lasting 6 months. Whe n no HLA-identical donor was available, patients aged <55 years underwent s tem cell harvest followed by autologous transplantation; patients aged grea ter than or equal to 55 years received standard maintenance treatment for 6 months. In the second year, maintenance treatment (all ages) was based on cycles of alpha-IFN (3 MU three times a week for 6 weeks) alternated with m ethotrexate/6-mercaptopurine continuously for up to 2 years from first demo nstration of CR. Thereafter, patients maintaining CR had the same schedule of alpha-IFN (6 weeks on, 6 off). Eight patients (6/8 first diagnosis, 2/2 relapsed) obtained morphological, immunological and cytogenetic CR with per sistent molecular positivity. Two with an HLA-identical donor had allogenei c bone marrow transplantation. Six proceeded with chemotherapy: one experie nced early relapse, three were autotransplanted, and two received maintenan ce. Five patients then received alpha-IFN as scheduled. All five are in con tinuous morphological and cytogenetic CR, with a longer mean duration of ma intained morphological CR (mean 46 months; range: 20-88) than in previous r eports of Ph+ ALL patients treated with chemotherapy regimens (excluding al logeneic BMT), alpha-IFN thus appears effective in this poor-risk subset of patients. This well-tolerated IFN-containing maintenance treatment could b e considered to reinforce intensified programs based on autologous stem cel l transplantation as an alternative to allogeneic transplantation in p190(B CR-ABL+) ALL patients (and by extension for Ph+ ALL patients) lacking an HL A-matched donor.