Objectives: Nearly all patients with multiple myeloma (MM) relapse or become refractory to front-line therapy. Several salvage therapies have been explored, but the optimal combination regimen has not been defined. We performed a case-matched study comparing patients with relapsed/refractory MM receiving thalidomide-dexamethasone alone or the combination thalidomide-dexamethasone-liposomal pegylated doxorubicin.
Methods: Forty-seven patients received thalidomide (100 mg/d), dexamethasone (40 mg p.o. on days 1-4 and 9-12), and pegylated liposomal doxorubicin (40 mg/m(2) on day 1 every 28 d) (ThaDD). Their clinical outcome was compared with that of 47 pair mates selected from patients treated at relapse with thalidomide (100 mg/d) and dexamethasone (40 mg p.o. on days 1-4) (Thal-Dex) and matched for age, beta2-microglobulin and previous therapy.
Results and conclusions: Overall response rate was significantly higher in ThaDD group (92% vs. 63.5%; P < 0.0001) as partial response rate (> or =PR) (75.5% vs. 59.5%; P = 0.077), very good partial response rate (> or =VGPR) (36% vs. 15%; P = 0.018) and near complete remission rate (> or =nCR) (30% vs. 10.5%; P = 0.002). Non-hematologic toxicity was similar in the two groups of patients whereas hematologic toxicity and infections were significantly higher in ThaDD patients. Median progression-free survival, event-free survival, and overall survival were significantly longer in patients receiving ThaDD than in those treated with Thal-Dex. ThaDD regimen significantly improved response rate and overall survival in comparison with Thal-Dex. Although the frequency of hematologic toxicity and infections resulted higher in ThaDD group compared with control group, they were not particularly frequent after adequate prophylaxis was added and were easily managed when occurred.