Maria-Victoria Mateos, MD, PhD, from the University Hospital of Salamenca, Salamenca, Spain, discusses follow-up data from the CASTOR trial, a study assessing the effects of daratumumab in combination with bortezomib and dexamethasone compared with bortezomib and dexamethasone alone, for patients with relapsed or refractory multiple myeloma (MM). Here, she describes the positive results from the trial, namely the drugs’ sustained efficacy and their high safety profile in patients over 65 and 75 years old. This interview was filmed at the American Society of Oncology (ASCO) 2017 Annual Meeting in Chicago, IL.