[Bortezomib in relapsed or refractory multiple myeloma: results in a cohort of 39 patients]

Bortezomib has presently become a significant rescue treatment in multiple myeloma (MM) due to its observed effectiveness and safety in multicenter trials. We have aimed to verify both aspects in a setting of non-selected patients.

This is an observational, prospective study of the cohort of relapsed or refractory MM patients treated with bortezomib in our Department. The variables analyzed were response, its duration, time to the treatment failure (TTF), overall survival (OS), response related conditions and toxicity. Statistical methods used were Fisher's exact test, log rank-test and Kaplan-Meier survival tables.

A total of 39 patients, 25 relapsed and 14 refractory to chemotherapy, started the treatment. The mean number of previous treatment was 2.3 and they received an average of 5.8 cycles of bortezomib. Complete response was achieved in 14 patients (36%), partial response in 12 (31%) and minor or no response in 13 ones (33%). Median duration of response was 8 months, median TTF was 10 months and median OS, from the onset of bortezomib was 16.5 months, with a median observation of live patients of 12.5 months. The response was more frequent in males (p = 0.019) and in patients with one previous treatment (p = 0.15). There were no significant differences regarding to TTF when we considered the cause of treatment (relapse or no response to chemotherapy) nor in the number of previous treatment regimes. The most frequent adverse events were reversible thrombocytopenia (31%), polyneuropathy (28%) and asthenia-anorexia (23%).

In our cohort of non-selected, relapsed or refractory MM patients, the observations found in the multicenter randomized trials results regarding response rate and duration, TTF OS and safety of bortezomib therapy were verified.