Impact of post-ASCT maintenance therapy on outcomes in patients with newly diagnosed multiple myeloma in Connect MM.

Autologous stem cell transplantation (ASCT) followed by lenalidomide maintenance therapy is the standard of care for transplant-eligible patients with newly diagnosed multiple myeloma (NDMM). Clinical trials show progression-free survival (PFS) benefits, with some studies (Cancer and Leukemia Group [CALGB] trial and meta-analysis) also showing overall survival (OS) benefits, but applicability to real-world clinical settings is unclear. Using data from Connect MM, the largest US-based observational registry of NDMM patients, we analyzed effects of maintenance therapy on long-term outcomes in 1450 treated patients enrolled from 2009 to 2011. Patients who received induction therapy and ASCT (n = 432) were analyzed from 100 days post-ASCT (data cut 7 January 2016): 267 received maintenance (80% lenalidomide-based [of whom 88% received lenalidomide monotherapy]); 165 did not. Lenalidomide maintenance improved median PFS and 3-year PFS rate vs no maintenance (50.3 vs 30.8 months [hazard ratio (HR), 0.62; 95% confidence interval (CI), 0.46-0.82; P < .001] and 56% vs 42%, respectively). Improvements in median OS and 3-year OS rate were associated with lenalidomide maintenance vs no maintenance (not reached in either group [HR, 0.54; 95% CI, 0.36-0.83; P = .005] and 85% vs 70%, respectively). Five hematologic serious adverse events were reported with lenalidomide maintenance (pancytopenia [n = 2], febrile neutropenia, anemia, and thrombocytopenia [n = 1 each]) and 1 with no maintenance (thrombocytopenia). Second primary malignancies occurred at rates of 1.38 and 2.19 events per patient-year in lenalidomide maintenance and no maintenance groups, respectively. Survival benefits associated with lenalidomide maintenance previously demonstrated in clinical trials were observed in this community-based Connect MM Registry.