Pediatric-Based Therapy for Young Adults with Newly Diagnosed Lymphoblastic Leukemia.

Abstract 2037

Poster Board II-14

Adolescents 14 to 21 years of age with de novo acute lymphoblastic leukemia (ALL) have improved outcomes if treated on pediatric chemotherapy regimens as opposed to adult regimens. Young adults with ALL may also benefit from chemotherapy modeled after pediatric regimens, though toxicities may be limiting. We report on 48 young adult patients between the ages of 12 to 40 years with de novo Philadelphia chromosome negative ALL treated with the augmented Berlin-Frankfurt-Munster (BFM) chemotherapy regimen. All patients have completed at least the initial 28 days of therapy (induction) consisting of high dose prednisone, pegylated asparaginase (PEG-asp), vincristine, daunorubicin and intrathecal treatments. The median age of the group was 20 yrs (14-36); 40 patients had pre-B ALL and 8 T-ALL, No infectious deaths were observed during induction. 45 (95%) patients achieved a remission by 29 days and 2 achieved remission after a 2 week extension of induction. One patient was refractory to therapy. 39 (81%) patients achieved a morphological marrow remission (<5% blasts) by day 15 of treatment (rapid early responders). Minimal residual disease (MRD) assessed by flow cytometry was negative at the end of induction for 30 (62%), positive in 10 (21%), suspicious in 6 (12%) and not available for 2 patients. In the 41 patients who completed 12 weeks of therapy, MRD was negative in 35 (85%) and positive in 6 (15%). 7 (15%) patients have relapsed or have refractory disease; 1 patient died in CR. Admission for fever of unknown origin with neutropenia occurred in 10 (21%) patients, an additional 10 (21%) patients had documented infections. Grade III-IV hepatic toxicity has been prominent: 22 (45%) increased transaminase, 14 (29%) hyperbilirubinemia. 9 (19%) patients had allergic reactions to PEG-asp, and 10 (21%) had thrombotic events. The majority of grade III-IV adverse events have been reversible. The median complete remission duration is 57 weeks (range 5-143). The overall survival at two years is 82%. In summary, this pediatric-based regimen for young adults with ALL effectively induces remission, both by morphology and by flow cytometry. Toxicity has been significant, but mostly transient and tolerable. Longer follow-up is needed to determine the long-term efficacy of this regimen in young adults with ALL.