OBJECTIVETo investigate the efficacy and safety of PAD [bortezomib (PS-341), doxorubicin and dexamethasone] regimen for relapsed or refractory multiple myeloma (MM).

METHODSSeventeen patients with relapsed or refractory MM received two to four 21-day cycles of PAD: an intravenous bolus of bortezomib (1.3 mg/m2) on days 1, 4, 8, and 11; doxorubicin 10 mg per day on days 1 to 4, and dexamethasone 40 mg on days 1-4. Response was evaluated according to International Myeloma Working Group Criteria (IMWG 2006), toxicity was graded according to NCI CTCAE (common terminology criteria for adverse events) v 3.0.

RESULTSAfter 2-4 courses of PAD, 14 patients (82.4%) response, including complete response (CR) in 4 (23.5%), very good partial response (VGPR) in 4 (23.5%), partial response (PR) in 6 (35.3%) and stable disease (SD) in 3 (17.6%). Median time to progression was 9.5 months. The median course to response was 1.6 (1-3). All of 5 patients with extramedullary plasmacytoma achieved at least PR after the first cycle therapy; the plasmacytoma disappeared after 1-2 cycles of PAD. The efficacy was independent of other prognostic factors such as beta2-MG. Adverse events included thrombocytopenia in 9 patients (52.9%), leukopenia in 4 (23.5%), peripheral neuropathy in 4 (23.5%), varicella herpes zoster in 3 (17.6%), fatigue in 6 (35.3%) and diarrhea in 2 (11.7%). All of these adverse reactions could be controlled with routine supportive treatment, only one patient died from respiratory failure during his fifth PAD cycle.

CONCLUSIONSPAD regimen should be considered as an appropriate treatment for relapsed or refractory MM, especially for MM with extramedullary plasmacytoma. Its efficacy is independent of traditional prognostic factors. The side effects are usually manageable.