Comparative effectiveness of lenalidomide/dexamethasone-based triplet regimens for treatment of relapsed and/or refractory multiple myeloma in the United States: An analysis of real-world electronic health records data.

Background: This retrospective longitudinal study compared the effectiveness of dexamethasone+lenalidomide (Rd)-based triplet regimens containing proteasome inhibitors (PIs) ixazomib (IRd), carfilzomib (KRd), and bortezomib (VRd) or monoclonal antibodies (MABs) elotuzumab (ERd) and daratumumab (DRd) in patients with relapsed/refractory multiple myeloma (RRMM)-including those with high cytogenetic risk-primarily treated at community oncology clinics in the United States.

Methods: Electronic health records of adult RRMM patients in a deidentified real-world database (01/01/2014-09/30/2020) who initiated IRd, KRd, VRd, ERd, or DRd in the second or later line of therapy (LOT) were analyzed. The index date was the date of initiation of each LOT and baseline was the 6-month pre-index period. Duration of therapy (DOT), time to next therapy (TTNT), progression-free survival (PFS), and overall survival (OS) were compared across regimens with multivariable Cox proportional hazards models.

Results: Of the 1,185 patients contributing 1,332 LOTs, 985 had standard cytogenetic risk (median age, 71 years) and 180 had high risk (median age, 69 years). Compared with other regimens, DRd was associated with longer DOT overall (adjusted hazard ratio [95 % confidence interval]: 1.84 [1.42, 2.38] vs. KRd, 1.65 [1.20, 2.28] vs. ERd, 1.58 [1.23, 2.04] vs. IRd, and 1.54 [1.18, 2.00] vs. VRd), and longer TTNT and PFS. KRd was associated with shorter OS compared with DRd (1.45 [1.01, 2.08]) and VRd (1.32 [1.01, 1.73]). High-risk patients had similar outcomes with all triplet regimens.

Conclusion: Although DRd improved clinical outcomes overall, Rd-based triplet regimens containing a PI or MAB are similarly effective in high-risk RRMM.