Overall survival with daratumumab, bortezomib, and dexamethasone for RRMM in the phase 3 CASTOR trial

At the primary analysis of CASTOR (median follow-up 7.4 months) daratumumab plus bortezomib and dexamethasone (D-Vd) significantly prolonged PFS versus Vd alone among patients with relapsed or refractory multiple myeloma (RRMM). Final analysis of the trial, at median 72.6 months (range 0.0-79.8), showed significant OS benefit with D-Vd over Vd. The OS benefit was seen in most subgroups, with the greatest benefit seen in patients with one prior line of therapy. The D-Vd arm also had significantly longer PFS2. Addition of D to Vd was tolerated, without new safety concerns. The authors conclude that these results, together with the OS benefit observed with daratumumab-lenalidomide-dexamethasone in the POLLUX trial, demonstrate for the first time an OS benefit with a daratumumab-containing regimen for RRMM.