Objective: To compare the efficacy and safety of standard or reduced doses of bortezomib combined with adriamycin and dexamethasone (PAD) in patients with multiple myeloma (MM).
Methods: Eighty-two newly diagnosed or refractory/relapsed patients received bortezomib [either 1.2-1.3 mg/m(2) (standard dose) or 1.0-1.1 mg/m(2) (reduced dose) on day 1, 4, 8 and 11], and adriamycin (10 mg/m(2)) plus dexamethasone (40 mg/m(2)) on day 1-4 at 3-week intervals for 1 to 6 courses. The International Myeloma Working Group Criteria were used to evaluate the response. Adverse events were graded according to the National Cancer Institute Common Toxicity Criteria (Version 3.0).
Results: Two courses of standard dose of PAD resulted in a similar response rate of partial and very good partial complete remissions (PR) compared with reduced dose (80.0% vs 80.8%, P=0.728). Grade III- Ⅳ neutropenia and thrombocytopenia were higher with standard dose than that with reduced doses of PAD (21.1% vs11.1%, P=0.270; 10.5% vs 6.3%, P=0.619, respectively). Grade III-Ⅳ bortezomib-induced peripheral neuropathy, herpes zoster, fatigue or abdominal distention were significantly higher with standard dose than that with reduced dose of PAD (15.8% vs 1.6%, P=0.037; 26.3% vs 6.3%, P=0.028; 36.8% vs 14.3%, P=0.046; 15.8% vs 1.6%, P=0.037, respectively).
Conclusion: Reduced dose of PAD appears to result in a similar overall response rate, but a better tolerance and safety compared with standard dose.