Escalation therapy with bortezomib, dexamethasone and bendamustine for patients with relapsed or refractory multiple myeloma.

In order to improve remission rates without causing undue toxicity, we treated 50 patients with relapsed/refractory multiple myeloma according to an institutional sequential treatment algorithm. Bortezomib was given as monotherapy (1.3 mg/m(2) on day 1 + 4 + 8 + 11) followed by the addition of dexamethasone in a first (40 mg on day 1 + 4 + 8 + 11) and bendamustine (50 - 100 mg/m(2) on day 1 + 8) in a second escalation step for patients with less than a minor response. Bortezomib monotherapy was sufficient in 23 (46%) patients, treatment escalation with dexamethasone was necessary in 20 (40%) patients and 7 (14%) patients needed triple combination therapy. Overall response rate was 84% while toxicity was manageable. Median time to progression and overall survival were 8 and 20 months, respectively. In conclusion, this treatment algorithm resulted in responses in the majority of heavily pre-treated patients while at the same time restricting the toxicity of triple combination therapy to only 14% of non-responding patients.