Objectives: To investigate the efficacy and toxicity of bortezomib based combination therapy for Chinese patients with relapsed or refractory multiple myeloma (MM), and to determine the combination regimen, dosage and cycles in application of bortezomib for MM therapy.
Methods: Forty-six patients with refractory or relapsed myeloma were treated with bortezomib (1.3 mg/m2) as an intravenous bolus twice weekly for 2 weeks on day 1, 4, 8, and 11 in a 3-4 week cycle, in combination with dexamethasone, dexamethasone plus thalidomide, CD (C-cytoxan, D-dexamethasone), MD (M-mitoxsnteone), DCEP (E-etoposide, P-platinol), and DT-PACE regimens (T-thalidomide, A-adriamycin). Response to bortezomib was evaluated according to the criteria of the International Myeloma Working Group (IMWG) before initiation of each cycle. Adverse events were graded according to the National Cancer Institute Common Toxicity Criteria, version 3.0. Forty-nine matched patients with relapsed and refractory MM who received thalidomide based combination therapy were used as a historical control group.
Results: Among 43 of the 46 patients whom could be evaluated, the overall response rate was 72.1% (the control group was 51.0%, P < 0. 05), including complete response in 5 patients (11.6%), very good partial response in 12 patients (27.9%), and partial response in 14 patients (32.6%). The overall response rate after one and two cycles was 30.2% and 58.1% (P < 0.05), respectively. The frequent adverse events were thrombocytopenia (62.8%), fatigue (55.8%), nausea (51.2%) and peripheral neuropathy (30.2%); all of the events could be tolerated. The most common adverse event in the control group was constipation( 69.4%), followed by fatigue (59.2%) and dizziness (46.9%).
Conclusions: Bortezomib based combination therapy is a new effective therapy in relapsed or refractory myeloma patients with a higher response rate and different toxicities as compared with thalidomide based combinations.