Human leukocyte interferon and intermittent high-dose melphalan-prednisone administration in the treatment of multiple myeloma: a randomized clinical trial from the myeloma group of central Sweden

: In a randomized clinical trial intermittent high-dose melphalan/prednisone (MP) treatment has been compared with human leukocyte interferon (IFN) administration. Three to 6 X 10(6) IU of IFN was given im daily. Therapy was continued to progression of the disease. Fifty-five patients were randomized to receive MP and 75 were randomized to receive IFN. Forty-four percent of the patients receiving MP responded to therapy as opposed to only 14% of the patients receiving IFN (P less than 0.001). This difference was mainly due to a low response rate in IFN-treated IgG myelomas, while the response rate for IgA and Bence Jones myelomas did not differ significantly between the two treatment groups. Median duration of response was shorter for IFN-responding patients (23 months) as compared to patients in the MP group (35 months). During follow-up, second-line therapy was given more frequently in the IFN group (91%) than in the MP group (59%). Time on initial treatment was significantly shorter in the IFN group (3 months) than in the MP group (19 months). Since more patients responded to second-line therapy in the IFN group than in the MP group, total survival did not differ significantly between the two groups.