Once-weekly subcutaneous administration of bortezomib in patients with multiple myeloma.

In patients with multiple myeloma (MM), once-weekly intravenous injection or twice-weekly subcutaneous injection (SC) of bortezomib has been proven to offer non-inferior efficacy to standard twice-weekly intravenous administration, with an improved safety profile. However, whether once-weekly SC bortezomib can further reduce the incidence rate of peripheral neuropathy (PN) and not compromise the efficacy remains to be investigated. 25 patients of MM treated with once-weekly SC bortezomib were reviewed in this study. The median treatment cycles were 4 (range, 2-9 cycles). Complete response (CR) rate was 52%, ≥very good partial response (VGPR) rate was 72%, and ≥partial response (PR) rate was 84%. 1-year and 2-year PFS rate was 63.0% and 34.3%, respectively, and 2-year OS rate was 100%. Any grade of PN was reported in 9 patients (36.0%), with 7 patients (28.0%) had grade 1 PN, and 2 patients (8.0%) had grade 2 PN. No patients reported grade 3/4 PN in this cohort. In conclusion, once-weekly subcutaneous administration of bortezomib offers excellent efficacy with a further improved safety profile, especially with regard to PN. It needs to be validated in future prospective randomized trials.