Most common treatment combinations in patients with lenalidomide-refractory RRMM after index date. Combinations with 1, 2, or 3 of the following were classified as doublet, triplet, or quadruplet therapy regimens, respectively: PI, immunomodulatory drug, anti-CD38 monoclonal antibodies, steroid, selinexor, belantamab mafodotin, and elotuzumab. Other treatment regimens included combinations that did not fall into any of the above categories.