Treatment with recombinant interferon-alpha-2C: multiple myeloma and thrombocythaemia in myeloproliferative diseases.

Forty-two patients with multiple myeloma were allocated to two groups to receive either polychemotherapy with vincristine, melphalan, cyclophosphamide and prednisolone, or recombinant interferon-alpha 2C monotherapy. The response rate of 43% in the interferon group was significantly lower than that in the chemotherapy group (89%). Patients with stage I disease showed better response rates than those with stage II or stage III disease. Eleven patients with thrombocythaemia due to polycythaemia vera, chronic myeloid leukaemia or essential thrombocythaemia were treated with recombinant interferon-alpha 2C and complete remissions were achieved in 7 of the 8 evaluable patients. Side-effects were common on interferon therapy, but could be reduced by dose reduction and were reversed by cessation of treatment.