Frailty impairs the feasibility of induction therapy but not of maintenance therapy in elderly myeloma patients: final results of the German Maintenance Study (GERMAIN)

The German Maintenance Study (GERMAIN) was designed to evaluate the impact of lenalidomide maintenance after induction therapy with bortezomib, melphalan and prednisolone (VMP) in transplant-ineligible newly diagnosed multiple myeloma (MM) patients. Due to poor accrual and high dropout rate, only 85 patients (planned 286) entered the trial and 40 (planned 200) were randomized to lenalidomide maintenance (n = 19) vs. observation (n = 21). The primary endpoint, improved progression-free survival, was not met (p = 0.3572). After a median follow-up of 12.9 months, median progression-free survival in the lenalidomide arm was 14.4 months and 11.4 months with placebo. The hazard ratio 0.621 (95% confidence interval: [0.224, 1.725]) was about the same as expected (0.625). However, with only 40 patients randomized, the actual power to detect a difference was 11%. Of patients receiving at least one dose of induction, 54% were frail according to a modified International Myeloma Working Group frailty score. Discontinuations were high during induction (47%), and affected mainly frail patients (54%). Despite a higher rate of adverse events in the lenalidomide arm (p = 0.0061), only 2 patients discontinued lenalidomide due to toxicity. A frailty assessment with appropriate dose modification for induction therapy should be mandatory for all elderly non-transplant-eligible myeloma patients.