Maintenance therapy with bortezomib plus thalidomide or bortezomib plus prednisone in elderly multiple myeloma patients included in the GEM2005MAS65 trial

Maintenance therapy has become a hot field in myeloma, and it may be particularly relevant in elderly patients because the major benefit results from the initial therapy. We report the results of a randomized comparison of maintenance with bortezomib plus thalidomide (VT) or prednisone (VP) in 178 elderly untreated myeloma patients who had received 6 induction cycles with bortezomib plus either melphalan and prednisone or thalidomide and prednisone. The complete response (CR) rate increased from 24% after induction up to 42%, higher for VT versus VP (46% vs 39%). Median progression-free survival (PFS) was superior for VT (39 months) compared with VP (32 months) and overall survival (OS) was also longer in VT patients compared with VP (5-year OS of 69% and 50%, respectively) but the differences did not reach statistical significance. CR achievement was associated with a significantly longer PFS (P < .001) and 5-year OS (P < .001). The incidence of G3-4 peripheral neuropathy was 9% for VT and 3% for VP. Unfortunately, this approach was not able to overcome the adverse prognosis of cytogenetic abnormalities. In summary, these maintenance regimens result in a significant increase in CR rate, remarkably long PFS, and acceptable toxicity profile. The trial is registered at www.clinicaltrials.gov as NCT00443235.