Favorable Prognosis in Patients With Multiple Myeloma and Lenalidomide‐Induced Skin Rash: A Multicenter Retrospective Study

Although lenalidomide is an essential treatment for multiple myeloma (MM), skin rashes are a common adverse event. This retrospective study aimed to examine the association between skin rash development during lenalidomide treatment and the prognosis of relapsed/refractory MM. All patients who received lenalidomide at 10 hospitals between July 2009 and December 2015 were included in the study. The relationship of skin rash development with disease progression and survival was evaluated. Multivariate analysis was performed to identify factors affecting disease progression or survival, including skin rash. Of the 245 patients analyzed, 70 developed skin rashes. The median progression-free survival (PFS) of patients with skin rashes was 22.4 months, whereas the median PFS for patients who did not develop skin rashes was 10.5 months (p = 0.003). The median overall survival for patients with and without skin rash was 42.6 and 24.6 months, respectively (p = 0.013). Multivariate regression analysis showed that skin rash was an independent prognostic factor for PFS (p = 0.009). In this study, patients with skin rashes during lenalidomide treatment had significantly better PFS than those without such symptoms, indicating that lenalidomide-associated skin rashes may be a predictor of clinical outcomes in patients with MM.