Maintenance treatment in multiple myeloma.

Maintenance chemotherapy has failed to demonstrate any benefit [1, 2]. Corticosteroid maintenance was found to prolong the duration of response; however, the effect on survival was controversial [3, 4]. Interferon-a represented a great hope in the 1980s but metaanalysis of randomized trials showed a modest increase in progression-free survival (PFS) and a minimal benefit in overall survival (OS) [5, 6]. Considering the cost and the side-effects of long-term treatment with interferon, this approach has been almost abandoned. Currently conventional chemotherapy is being replaced by combinations using novel agents (thalidomide, bortezomib or lenalidomide). These new combinations are superior to the classical chemotherapy regimens in terms of remission rate, PFS and OS. Interestingly they induce complete remission (CR) rates that are comparable to those achieved with autologous stem cell transplantation (ASCT). However, until now, the optimal treatment duration and the interest of maintenance therapy once maximal response is achieved are unknown. Randomized studies are addressing this question.