Durability of responses to interferon alfa-2b in advanced hairy cell
leukemia
MJ Ratain, HM Golomb, RG Bardawil, JW Vardiman, CA Westbrook, LS Kaminer, BC Lembersky, MA Bitter and K Daly
Previous studies have demonstrated that significant hematologic improvement
occurs in the majority of patients with hairy cell leukemia (HCL) treated
with partially purified or recombinant interferon (IFN). Fifty-three
patients received IFN alfa-2b for at least 3 months in a dose of 2 X 10(6)
U/m2 subcutaneously thrice weekly. Of the 49 patients evaluable for
response (at least 6 months of IFN therapy), there were ten complete
responses and 29 partial responses for a total response rate of 80%. The
peripheral blood counts and bone marrow continued to improve over the
course of a full year of therapy. IFN was well tolerated, with no patients
discontinuing therapy because of toxicity. Transient myelosuppression
occurred in most patients during the first 1 to 2 months of therapy,
occasionally precipitating a transfusion requirement. After IFN treatment
was discontinued, there was a marked decrease in normal marrow elements and
a relative increase in marrow hairy cells. This was associated with a
transient increase in normal elements in the peripheral blood. Only one of
24 patients followed after receiving IFN for a median of 8.5 months (range,
3 to 16 months) has required further therapy. We conclude that low-dose IFN
alfa-2b is highly effective in advanced HCL; responding patients should be
treated for at least 1 year. The decision to initiate a second course of
IFN therapy should be based primarily on peripheral blood counts and the
clinical status of the patient rather than on the bone marrow.
Volume 69,
Issue 3,
pp. 872-877,
03/01/1987
Copyright © 1987 by The American Society of Hematology
