[Effects of bortezomib at different doses in combination with dexamethasone in treatment of relapsed or refractory multiple myeloma: a comparative study].

OBJECTIVE

To investigate the efficacy and toxicity of bortezomib of different doses in combination with dexamethasone for the treatment of relapsed or refractory multiple myeloma (MM).

METHODS

23 patients with relapsed or refractory MM, 10 males and 13 females, aged 65 (42-86), were randomized to 2 groups: low dose group receiving intravenous 1.0 mg/m2 bortezomib (n=10) on days 1, 4, 6, and 11 (twice weekly) combined with dexamethasone 20 mg/d on days 1-4, with 3 weeks as a course of treatment, and (20 standard dose group: receiving intravenous 1.3 mg/m2 bortezomib (n=13) combined with dexamethasone. The patients were followed up for 9.5 (3-15) months. The effect was determined using modified European Group for Blood and Marrow Transplantation (EBMT) criteria.

RESULTS

The complete response (CR) + partial response (PR) rate of the 1.0 mg/m2 bortezomib group was 70.0%, not significantly different from that of the 1.3 mg/m2 bortezomib group (61.5%, P > 0.05). The relief rate (CR + near CR rate) of the 1.0 mg/m2 bortezomib group was 20.0% not significantly different from that of the 1.3 mg/m2 bortezomib group (38.5%, P > 0.05). Only 1 case of adverse event over the grade 3 of National Cancer Institute Common Terminology Criteria for Adverse Events occurred in the 1.3 mg/m2 bortezomib group. Five cases of infectious fever and 2 cases of treatment-associated death occurred in the 1.3 mg/m2 bortezomib group.

CONCLUSION

Bortezomib at the dose of 1.3 mg/m2 is more effective in treatment of relapsed or refractory MM than that at the dose of 1.3 mg/m2 and has more side effects.