Retreatment and prolonged therapy with subcutaneous bortezomib in patients with relapsed multiple myeloma: A randomized, controlled, phase III study.

Abstract

This randomized, international, multicenter, open-label phase III study investigated the effects of experimental retreatment with subcutaneous bortezomib plus dexamethasone (VD) followed by prolonged bortezomib therapy vs standard VD retreatment in patients with relapsed/refractory multiple myeloma. Patients were randomized (2:1) to receive either experimental (n=53) or standard (n=27) retreatment, stratified by the number of prior therapy lines. The study was terminated prematurely with insufficient enrollment to adequately compare the retreatment therapies; results should be considered descriptive. After a median follow-up of 21.2 and 20.0months in the experimental and standard arms, respectively, the median progression-free survival (primary endpoint) was 7.2months (95% confidence interval 5.7-9.0) vs 7.8months (4.9-11.7). The overall response rate was 66% and 52% for experimental and standard retreatment regimens, respectively. Thrombocytopenia was the most common and most differentially observed grade ≥3 adverse event (experimental: 9% vs standard: 22%). Any-grade peripheral neuropathies (including peripheral sensory neuropathies) were reported in 23% vs 37% of patients. This study showed no significant benefit with experimental vs standard VD retreatment therapy. Further investigations are required to determine whether the experimental retreatment regimen is a suitable alternative to the current standard retreatment regimen.