Predictors of lenalidomide maintenance duration after autologous stem cell transplant in patients with multiple myeloma.

BACKGROUND:For patients with multiple myeloma (MM) who have undergone autologous stem cell transplant (auto-SCT), the immunomodulatory agent lenalidomide is a first-line option for maintenance therapy. Because longer durations of lenalidomide maintenance are associated with improved survival, identifying strategies to avoid premature cessation of maintenance is an important priority in the post-transplant setting. OBJECTIVES:The primary objective of this analysis was to identify specific clinical predictors of lenalidomide treatment duration that could guide optimal medication management. Key secondary objectives included predictors of intolerable toxicity, rationale for lenalidomide dose reduction/discontinuation, and characterization of dose adjustments. STUDY DESIGN:This retrospective, multi-center cohort study included adults with MM who underwent auto-SCT and initiated maintenance lenalidomide between 01/01/2012 and 02/28/2021. Variables assessed as potential predictors of maintenance duration or intolerable toxicity included age, body mass index (BMI), Eastern Cooperative Oncology Group (ECOG) performance status at time of auto-SCT, renal function, initial lenalidomide dose, use of combination maintenance therapy, and cytogenetic risk category. RESULTS:Among 299 patients included, the median age at time of auto-SCT was 62 years (range 30-77). The majority of patients had standard-risk cytogenetics (64%) and an ECOG performance status of 0 or 1 (72%). In the overall population, the median duration of maintenance was 1.3 years (range 0.3-8.6 years). The median initial dose of lenalidomide was 10 mg daily (range 2.5-25 mg). During the study period, 35% of patients had a dose reduction due to toxicity, 21% stopped lenalidomide due to disease progression, and 19% stopped due to toxicity. Multivariate linear regression analyses did not identify any significant predictors of lenalidomide duration or discontinuation due to intolerable toxicity. The most frequently reported toxicities leading to discontinuation were cytopenias, rash, and fatigue. CONCLUSION:This analysis did not identify any significant risk factors to predict the duration of lenalidomide maintenance or discontinuation for toxicity following auto-SCT in patients with MM. While limited by the retrospective design and relatively small sample size, our findings suggest that a priori