Maria-Victoria Mateos, MD, PhD, of the University of Salamanca, Salamanca, Spain, discusses the updated analysis of the CASTOR trial (NCT02136134) with us at the European School of Haematology (ESH) International Conference on Multiple Myeloma 2018, held in Mandelieu, France. This trial investigated daratumumab plus bortezomib/dexamethasone for relapsed/refractory multiple myeloma, and this follow-up showed excellent response rates and survival benefit, in addition to indicating the group that will receive the maximum benefit from this regimen.