Long-term therapeutic efficacy and toxicity of recombinant interferon-alpha 2a in polycythaemia vera.
We report on long-term therapeutic efficacy and toxicity of recombinant interferon-alpha 2a (rIFN-alpha) in a series of 38 patients with polycythaemia vera (PV). In all patients haematocrit was first brought into the normal range by venesection; rIFN-alpha was then begun at a starting weekly dose of 9,000,000 IU. Complete response (CR) was defined as persistence of normal haematocrit without venesection and partial response (PR) as >50% reduction of phlebotomy requirement. Eleven patients (28.9%) achieved CR and 8 (21.0%) PR. Median duration of treatment for all responsive patients was 40 months; 12 patients are still responsive and under treatment after 13, 15, 25, 35, 40, 41, 43, 49, 50, 51, 52 and 52 months of therapy with rIFN-alpha. In responsive patients, rIFN-alpha also normalized leucocyte counts, platelet counts and spleen enlargement; rIFN-alpha also relieved generalized pruritus in all 10 patients displaying this symptom. Early toxicity (flu-like syndrome) was observed in 23.6% and late toxicity (severe weakness) in 13.1% of patients, requiring rIFN-alpha treatment suspension in all cases. Progression to leukaemia was observed in none of the 10 patients treated only with rIFN-alpha and in one of the 12 who received alkylating agents before enrolment in this study. According to these data, rIFN-alpha seems to be an effective and safe treatment option for PV.
Foa
P
P
Institute of Medical Sciences, University of Milan, Ospedale Maggiore I.R.C.C.S., Italy.
Massaro
P
P
Caldiera
S
S
LaTargia
M L
ML
Iurlo
A
A
Clerici
C
C
Fornier
M
M
Bertoni
F
F
Maiolo
A T
AT
D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use*; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D010976:Platelet Count; D011087:Polycythemia Vera / Q000097:blood / Q000628:therapy*; D011994:Recombinant Proteins; D013163:Splenomegaly; D013997:Time Factors; D016896:Treatment Outcome
D000077190:Interferon alpha-2; D016898:Interferon-alpha; D011994:Recombinant Proteins