Salvage therapy with pegylated liposomal doxorubicin, bortezomib, cyclophosphamide, and dexamethasone in relapsed/refractory myeloma patients.

Objectives: In vitro studies have shown synergistic anti-myeloma effects of bortezomib combined with alkylating agents or anthracycline. We tested safety and efficacy of the combination of bortezomib, doxorubicin cyclophosphamide, and dexamethasone (ABCD) in the treatment of relapsed/refractory myeloma.

Methods: ABCD consisted of bortezomib given intravenous (IV) at dosage 1.3 mg/m(2) , dexamethasone 40 mg IV on days 1, 4, 8, and 15, pegylated liposomal doxorubicin (PLD) 20 mg IV on days 1 and 15, plus cyclophosphamide 100 mg/d per os for 15 d. Between January 2008 and February 2009, 24 patients received a median of four 28-d ABCD cycles (range 1-6). All patients had been already treated with a median of two previous lines of treatment (range 1-6): 38% were resistant to previous therapies and 62% were relapsed.

Results: Clinical response was observed in 12 patients (50%), including 29% of very good partial remissions or better. Side effects included hematological toxicity (31% any grade), grades 3-4 thrombocytopenia (9%), grades 3-4 anemia (17%). Non-hematological toxicity affected 32% of administered cycles and included gastrointestinal disturbances (54%), peripheral neuropathy (8%), and infections (8%). After a median follow-up of 21.5 months (range 2-44 months), median of progression-free survival (PFS) was 8.7 months and median overall survival was 22.5 months. Achieving at least partial response within the second cycle was associated with a better PFS (19.5 months vs. 3.5 months), P = 0.03, HR 0.35 (CI 95% 0.13-0.90).

Conclusion: ABCD is safe and effective for relapsed/refractory MM subjects previously treated with novel agents.