Fourteen adult patients with newly-diagnosed acute lymphoblastic, leuk
emia (ALL), and lymphoblastic lymphoma, were treated with a dose-inten
se induction regimen. This regimen was designed to increase the fracti
on of patients achieving an early complete remission, in an attempt to
increase the fraction of patients who are long-term disease-free surv
ivors. The induction regimen included vincristine, prednisone, interme
diate-dose cytarabine (Ara-C), and idarubicin, all given during the fi
rst week of therapy. This combination led to significant hepatic, gast
rointestinal, infectious, and neurologic toxicity. There was unaccepta
ble treatment-related mortality (29%). After the first eight patients,
the study was modified, omitting the Ara-C from the induction phase.
Gastrointestinal morbidity was less in the cohort treated without Ara-
C; however, infectious morbidity persisted at unacceptable levels and
this program was terminated as too toxic to administer. There were nin
e complete remissions, three early deaths, and two patients with resis
tant disease. There have been six relapses, three of which occurred in
patients who, because of protracted grade III/IV toxicity, were no lo
nger receiving chemotherapy. With a minimum follow-up of 20 months, on
ly three patients are still alive. We conclude that this combination o
f vincristine, prednisone, Ara-C, and idarubicin, is too toxic to be u
sed as induction therapy for adult patients with ALL and lymphoblastic
lymphoma.