Treatment of MM patients with first relapse. Choice of treatment of patients with first relapse is dependent on patient-, tumor-, and treatment-related features. Patients, who progress on lenalidomide, can be treated with proteasome inhibitor–based therapy or a pomalidomide-based regimen. Patients who are not lenalidomide-refractory can be treated with a lenalidomide-based regimen. Alternatively, these patients may also receive retreatment with proteasome inhibitors if there is a treatment-free interval of >6 months. Regimens with red contour were evaluated in phase 3 trials; regimens with green contour were evaluated in phase 1 or 2 trials. Bort, bortezomib; Carfil, carfilzomib; CRd, cyclophosphamide-lenalidomide-dexamethasone; dara-Kd, daratumumab-carfilzomib-dexamethasone; dara-Pd, daratumumab-pomalidomide-dexamethasone; dara-Rd, daratumumab-lenalidomide-dexamethasone; dara-Vd, daratumumab-bortezomib-dexamethasone; elo-Pd, elotuzumab-pomalidomide-dexamethasone; elo-Rd, elotuzumab-lenalidomide-dexamethasone; elo-Vd, elotuzumab-bortezomib-dexamethasone; IRd, ixazomib-lenalidomide-dexamethasone; isa-Kd, isatuximab-carfilzomib-dexamethasone; Isa-Pd, isatuximab-pomalidomide-dexamethasone; Kd, carfilzomib-dexamethasone; KPd, carfilzomib-pomalidomide-dexamethasone; Len, lenalidomide; Pano-Vd, panobinostat-bortezomib-dexamethasone; PCd, pomalidomide-cyclophosphamide-dexamethasone; Pom, pomalidomide; PVd, pomalidomide-bortezomib-dexamethasone; Rd, lenalidomide-dexamethasone; SVd, selinexor-bortezomib-dexamethasone; VCd, bortezomib-cyclophosphamide-dexamethasone; Vd, bortezomib-dexamethasone.