Bortezomib, doxorubicin, and dexamethasone combination therapy followed by thalidomide and dexamethasone consolidation as a salvage treatment for relapsed or refractory multiple myeloma: analysis of efficacy and safety.

We conducted a phase 2 study with bortezomib, doxorubicin, and dexamethasone (PAD) followed by thalidomide and dexamethasone (TD) in patients with relapsed multiple myeloma (MM). Forty patients were enrolled between November 2005 and October 2007, with follow-up continuing until January 2009. Efficacy could be assessed in 37 patients. The overall response rate to PAD followed by TD was 83.6%: complete response 51.4%, near-complete response 13.4%, very good partial remission 5.4%, and partial response 13.4%. The median follow-up was 27 months (range 13-39). The median progression-free survival (PFS) from the start of treatment was 18 months (95% CI, 9.7-26.2 months), with a 1-year PFS rate of 56.9% and 3-year PFS rate of 25.7%. Median overall survival was 35.1 months (95% CI, 18.5-51.7), with a 1-year survival rate of 75% and 3-year survival rate of 27.3%. One hundred seventy-eight PAD cycles (median 6, range 1-6) in 38 patients were assessable for safety. The most common hematologic toxicity was thrombocytopenia, with grade 3-4 in 35.8%. Sensory neuropathy occurred at grade 2 in 26.3% and grade 3 in 10.3%. Two hundred TD treatment cycles (median 4, range 0-12 cycles) were administered. Most adverse events were of mild degree and manageable. PAD followed by TD in patients with relapsed MM is very effective and tolerable.