Interferon maintenance therapy for patients with chronic lymphocytic
leukemia in remission after fludarabine therapy
S O'Brien, H Kantarjian, M Beran, LE Robertson, C Koller, S Lerner and MJ Keating
Department of Hematology, University of Texas M.D. Anderson Cancer Center,
Houston 77030, USA.
Many patients with chronic lymphocytic leukemia (CLL) achieve remission
after treatment with fludarabine chemotherapy. Most of these patients,
however, later experience relapse. In addition, immunologic deficits may
persist even in patients in complete remission; lymphopenia, predominantly
involving the CD4 population, is universal after fludarabine therapy. We
used recombinant alpha interferon (IFN-alpha) maintenance therapy in
patients with CLL who achieved remission in response to fludarabine therapy
to determine its effect on residual disease, assessed by either bone marrow
biopsy or flow cytometry, and on immune restoration. Thirty-one patients
were treated with IFN-alpha (3 x 10(6) U by subcutaneous injection three
times weekly). Twenty-two patients (71%) were in complete remission (CR)
and nine (29%) were in partial remission (PR). Of the 22 patients in CR, 21
(95%) had evidence of residual disease at the start of IFN-alpha therapy.
Low CD4 levels were noted in 93% of patients, low IgG levels in 45%, and
anergy or hypoergy in 52%. Only one patient in PR achieved a CR on
IFN-alpha therapy: the only patient who had had no prior fludarabine but
had been treated with chlorambucil and prednisone. All patients in CR with
minimal residual disease had persistent disease after IFN-alpha treatment.
There were no increases in CD4 counts or IgG levels; three patients with
borderline responses to skin testing had an increase in the number of
positive tests while on IFN-alpha. The time to progression was no different
in patients treated with IFN-alpha than in a historical control group of
patients who had received no further therapy after fludarabine. In summary,
the use of IFN-alpha maintenance did not eradicate residual disease,
restore immune function, or prolong remissions in patients with CLL
responsive to fludarabine.
Volume 86,
Issue 4,
pp. 1298-1300,
08/15/1995
Copyright © 1995 by The American Society of Hematology
