Real-World Use and Effectiveness of Carfilzomib Plus Dexamethasone in Relapsed/Refractory Multiple Myeloma in Europe

SIMPLE SUMMARY: Multiple treatment regimens are approved for relapsed/refractory multiple myeloma (RRMM), but evidence of their real-world use is limited. This study included 701 patients across 11 countries in Europe and Israel between March 2017 and March 2020, and examined the real-world use of carfilzomib in adults with RRMM who received at least one prior line of therapy. Here, we describe the results for 271 patients who received carfilzomib and dexamethasone (Kd). The overall response rates (ORR) with Kd treatment were high, both overall (68.8%) and by treatment line. In patients who are refractory to lenalidomide, the ORR of 59.9% is an encouraging outcome. In patients refractory to anti-CD38 treatment, the ORR was higher for those receiving Kd in earlier (66.7%) than later lines (fourth line or later, 49.1%). Our study demonstrates that Kd is used effectively, with an acceptable safety profile in routine clinical practice. ABSTRACT: This prospective, observational study examined the real-world use of carfilzomib across 11 European countries in adults with relapsed/refractory multiple myeloma (RRMM) who received at least one prior line of therapy. Carfilzomib and dexamethasone (Kd) use, effectiveness and safety were analyzed. In total, 271 patients received Kd among 701 adults enrolled. The median relative dose intensity of carfilzomib was 82.7% (20/56 mg/m(2), twice weekly). The overall response rate (ORR) to Kd was 68.8% (95% confidence interval [CI], 62.7–74.5): 79.2% in second line (2L), 71.6% in third line (3L) and 63.1% in fourth line or later (4L+). The ORR was 59.9% (95% CI, 51.1–68.1) in the lenalidomide-refractory subgroup and 67.7% (95% CI, 48.6–83.3) in the not lenalidomide-refractory subgroup. In the anti-CD38 refractory subgroup, the ORR was 51.6% (95% CI, 38.6–64.5); ORRs were higher when Kd was received at 2L/3L (66.7%) than at 4L+ (49.1%). Overall, patients were treated for a median time of 7.7 months. One-fifth of patients reported treatment-related treatment-emergent adverse events (≥grade 3), with a safety profile consistent with previous clinical trials. This study demonstrated the real-world use, effectiveness and safety of Kd in patients with RRMM. Despite the increasing number of new therapeutic strategies to treat RRMM, Kd remains a safe and effective option, even for older, frail and lenalidomide- or anti-CD38 mAb-refractory patients.