Improved response with post-ASCT consolidation by low dose thalidomide, cyclophosphamide and dexamethasone as first line treatment for multiple myeloma

The use of consolidation or maintenance to improve disease response, and hence clinical outcome, following autologous stem cell transplantation (ASCT) remains the subject of intense clinical research. We carried out a single-arm study to assess the toxicity and efficacy of a short block of consolidation therapy with cyclophosphamide, low dose thalidomide and dexamethasone (CTD) in patients within 6 months following ASCT, as part of frontline therapy for symptomatic multiple myeloma. Forty-five patients who had not progressed were enrolled on the study, and 43 completed treatment on protocol. This regimen was well tolerated soon after ASCT, with only grade 1/2 toxicity apart from neutropenia, and no long-term sequelae. Importantly, CTD consolidation improved the depth of response in treated patients, increasing the complete/very good partial response rate from 44% at 3 months, to 72% at 12 months, which was significantly higher compared with a historical group of control patients (P = 0.002). There was a trend to longer progression-free survival that favoured the study group. Consolidation therapy did not adversely affect subsequent disease response to salvage therapies at relapse. We conclude that CTD consolidation may be a useful, non-toxic and cost-effective strategy to deepen disease response following ASCT, and deserves further study in a randomized trial.