Open Access

Marc-Andrea Bärtsch, Elias K. Mai, Thomas Hielscher, Uta Bertsch, Hans J. Salwender, Markus Munder, Stephan Fuhrmann, Ulrich Dührsen, Peter Brossart, Kai Neben, Jana Schlenzka, Christina Kunz, Marc-Steffen Raab, Jens Hillengaß, Anna Jauch, Anja Seckinger, Dirk Hose, Steffen Luntz, Pieter Sonneveld, Henk Lokhorst, Hans Martin, Martin Görner, Martin Hoffmann, Hans-Walter Lindemann, Helga Bernhard, Igor-Wolfgang Blau, Christof Scheid, Britta Besemer, Katja C. Weisel, Mathias Hänel, Jan Dürig, Hartmut Goldschmidt

• Lenalidomide (LEN) maintenance (MT) post autologous stem cell transplantation (ASCT) is standard of care in newly diagnosed multiple myeloma (MM) but has not been compared to other agents in clinical trials. We retrospectively compared bortezomib (BTZ; n = 138) or LEN (n = 183) MT from two subsequent GMMG phase III trials. All patients received three cycles of BTZ-based triplet induction and post-ASCT MT. BTZ MT (1.3 mg/m2 i.v.) was administered every 2 weeks for 2 years. LEN MT included two consolidation cycles (25 mg p.o., days 1–21 of 28 day cycles) followed by 10–15 mg/day for 2 years. The BTZ cohort more frequently received tandem ASCT (91% vs. 33%) due to different tandem ASCT strategies. In the LEN and BTZ cohort, 43% and 46% of patients completed 2 years of MT as intended (p = 0.57). Progression-free survival (PFS; HR = 0.83, p = 0.18) and overall survival (OS; HR = 0.70, p = 0.15) did not differ significantly with LEN vs. BTZ MT. Patients with <nCR after first ASCT were assigned tandem ASCT in both trials. In patients with <nCR and tandem ASCT (LEN: n = 54 vs. BTZ: n = 84), LEN MT significantly improved PFS (HR = 0.61, p = 0.04) but not OS (HR = 0.46, p = 0.09). In conclusion, the significant PFS benefit after eliminating the impact of different tandem ASCT rates supports the current standard of LEN MT after ASCT.