Lack of head-to-head trials highlights a need for comparative real-world evidence of proteasome inhibitors plus Rd.Methods: In this retrospective, US population-representative EHR study of RRMM patients initiating IRd, KRd, or VRd in line of therapy (LOT) ≥2 between 1/2014 and 9/30/2018, 664 patients were treated in LOT ≥2 with: IRd, n = 168; KRd, n = 208; VRd, n = 357. Median age was 71/65/71 years; 67%/70%/75% had a frailtymodified score of intermediate/frail; 20%/28%/13% had high cytogenetic risk in I-/K-/V-Rd groups. Risk of PI-triplet discontinuation was lower for I- vs. K-Rd (HR: 0.71) and I- vs. V-Rd (HR: 0.85); unadjusted, median TTNTs (months): 12.7/8.6/14.2 (LOT ≥2) and 16.8/9.5/14.6 (LOT 2-3) (I-/K-/V-Rd). Adjusted TTNT was comparable between I-/K-/V-Rd in LOT ≥2 with a TTNT benefit among intermediate/frail patients for I- (HR: 0.70; P=0.04) and V- (HR: 0.73; P<0.05) vs. K-Rd. I/K/V-Rd triplets were comparable in TTNT overall, but IRd and VRd were associated with longer TTNT in intermediate/frail patients than KRd. The results suggest a trial-efficacy/real-world-effectiveness gap, especially for KRd, underlining the limited generalizability of trial results where >50% of patients are excluded. Individualized treatment based on patient characteristics, such as frailty status, is especially pertinent in an elderly RRMM population.

Department of Hematology and Medical Oncology Icahn School of Medicine at Mount Sinai New York NY USA

Department of Hematology Erasmus MC Cancer Institute Rotterdam The Netherlands

Division of Hematology Oncology Department of Medicine Mayo Clinic Jacksonville FL United States

Global Outcomes Research Millennium Pharmaceuticals Inc A Wholly Owned Subsidiary of Takeda Pharmaceutical Company Limited Cambridge MA USA

Hematology and Medical Oncology Department of Clinical Therapeutics National and Kapodistrian University of Athens Athens Greece

Jerome Lipper Myeloma Center Department of Medical Oncology Dana Farber Cancer Institute Boston MA USA

Scientific Consulting Xcenda Palm Harbor FL USA

University Hospital Ostrava and Faculty of Medicine University of Ostrava Ostrava Czech Republic

References provided by Crossref.org

Lenalidomide based triplets in relapsed/refractory multiple myeloma: analysis of the Czech Myeloma Group

Ixazomib, Lenalidomide and Dexamethasone in Relapsed and Refractory Multiple Myeloma in Routine Clinical Practice: Extended Follow-Up Analysis and the Results of Subsequent Therapy

Real-world comparative effectiveness of triplets containing bortezomib (B), carfilzomib (C), daratumumab (D), or ixazomib (I) in relapsed/refractory multiple myeloma (RRMM) in the US

Management of patients with multiple myeloma beyond the clinical-trial setting: understanding the balance between efficacy, safety and tolerability, and quality of life