The survival benefit of carfilzomib, dexamethasone and daratumumab (KdD) in relapsed or refractory multiple myeloma is relatively consistent regardless of prior lines of therapy.

In the phase III CANDOR trial published last year, KdD was shown to significantly improve PFS (HR 0·63) compared to carfilzomib plus dexamethasone (Kd).

Now, a subgroup analysis of the CANDOR trial has found that neither the number of prior lines of therapy or the type of prior therapy substantially impacts that PFS improvement.

The sub-analysis, published in the British Journal of Haematology, found the PFS HR for a single prior line of therapy was 0.679 and 0.705 for two or more prior lines of therapy.

Similarly, the PFS HR was 0.529 for subgroups with exposure to lenalidomide and 0.708 for those without; 0.619 for prior bortezomib/ixazomib and 0.583 for those patients not previously exposed.

The PFS HR for the subgroup of patients refractory to lenalidomide was 0.474 and 0.738 for those not refractory; 0.840 for those refractory to bortezomib/ixazomib and 0.531 for those not refractory.

Rates of any grade adverse events (AEs), Grade ≥3 AEs, AEs leading to carfilzomib or daratumumab discontinuation, and deaths due to AEs were generally consistent across subgroups for KdD and Kd.

“In this subgroup analysis of CANDOR, efficacy and safety results were generally consistent with the benefit of KdD over Kd observed for the overall analyses in the intention-to-treat population,” the investigators said.

“At a median follow-up of ~17 months, PFS HRs for KdD versus Kd ranged from 0.47 to 0.84 across subgroups, comparable to the statistically significant PFS HR of 063 observed in the CANDOR primary analysis.”

“The MRD-negative CR rates were higher for the KdD group than the Kd group, regardless of previous drug exposure/refractory status.”

The investigators, led by Associate Professor Hang Quach from St Vincent’s Hospital Melbourne and the University of Melbourne, said their results confirm KdD as an important treatment option for patients with RRMM regardless of previous exposure or resistance to standard front-line treatments.