EFFICACY AND SAFETY OF HUMAN-LEUKOCYTE INTERFERON-ALPHA TREATMENT IN PATIENTS YOUNGER THAN 60 YEARS OF AGE WITH POLYCYTHEMIA-VERA

Objectives. To evaluate the therapeutic activity and toxicity of human leucocyte interferon-alpha (lIFN-alpha) in patients with polycythaemi a vera (PV) aged less than 60 years. Design. An open clinical study. S etting. Department of Medical Sciences, Regina Apostolorum Hospital, A lbano Laziale, and Chair of Haematology, University of Rome 'Tor Verga ta', S. Eugenio Hospital, Rome, Italy. Subjects. Fourteen patients wit h PV and aged < 60 years who had active disease as indicated by the ne ed for phlebotomy and/or cytoreductive therapy. Interventions. lIFN-al pha was administered subcutaneously at the starting dose of 3 MU thric e weekly. The interferon dose could be escalated to six MU thrice week ly if it was well tolerated and disease was not controlled after three months of treatment at the lower dose. Main outcome measures. Change in phlebotomy requirements, spleen size, pruritus score and haematolog ical parameters after 6 months of treatment. Evaluation of lIFN-alpha side effects. Results. Complete or partial disease control was achieve d in 13 patients. Six patients achieved a complete response (CR) and f our a partial response (PR) after 3 months of therapy. Dose escalation in partial or nonresponders resulted in two patients switching from a status of PR to CR, and three other patients achieving a partial resp onse after being unresponsive to the lower dosage. Human leucocyte int erferon-alpha therapy significantly improved (P < 01) phlebotomy requi rements, the degree of splenomegaly, pruritus scores, iron stores and MCV values, and platelet and leucocyte counts. A mild flu-like syndrom e (low-grade fever, nausea and myalgias) appeared during the early pha se of therapy in the majority of patients, but no patient had to disco ntinue lIFN-alpha because of intolerance. Conclusions. Subcutaneous hu man leucocyte interferon-alpha appears an effective and well tolerated therapy in the management of PV-associated myeloproliferation and pru ritus in patients aged less than 60 years.