Velcade an Active Agent for Multiple Myeloma Patients. Experience of a Single Center.

Velcade (PS-341, Bortezemib), a proteasome inhibitor, has recently been approved for the treatment of relapsed and refractory multiple myeloma (MM). We hereby report the results obtained using this new drug at our center. Between April 2003 and December 2004 we treated 23 patients with MM. The patient population consists of 13 males and 10 females, with a median age of 53 years (range 32–72); 16 were IgG MM, 6 IgA, 1 light chain. All patients were in stage III of their disease, with a median time of observation (from diagnosis to Velcade therapy) of 59 months (range 11–120), were pretreated with at least two lines of therapies and were refractory or in relapse after the last treatment. Velcade 1.3 mg/m² was scheduled on days 1, 4, 8 and 11 of a 21-day treatment cycle for 8 cycles according to the tolerability and response. All cycles were delivered in day hospital. A median of 6 cycles (range 3–8) were administered to the overall population. Eleven patients concluded their program, while 12 discontinued the treatment: 1 because she received an allogeneic stem cell transplantation, 7 for adverse events and 4 due to disease progression. In this heavily pretreated population, our primary end point was to obtain a decline in the monoclonal component (MC) of at least 25%. All patients were considered evaluable for response because treated with at least 3 cycles of therapy. Thirteen patients responded to treatment: 1 (4%) obtained a disappearance of the MC, 4 (17%) achieved a reduction of the MC level >75% and 8 (34%) >50%. Six further patients (26%) obtained a decline in the MC <25%. The median number of cycles required to achieve a response was 3 (range 1–8) and the median duration of response was 6 months, with 8 patients presently still responsive. Among the responding patients, 5 relapsed and 4 of them have died due to disease progression. Among the 4 patients (17%) who did not respond to Velcade, 1 died. The majority of adverse events, which resolved with the discontinuation of treatment, were nausea, vomiting, diarrhea, fatigue, thrombocytopenia and peripheral neuropathy. Taking into consideration the very poor prognostic likelihood of our patients, this study adds further evidence con the efficacy of this new drug in MM. Velcade can be considered an effective anti-myeloma drug even though its toxicity must be taken into account in designing new clinical trials.