ALTITUDE-1: Real-world Treatment Patterns Associated with elranatamab Among Patients with Multiple Myeloma
Introduction/Background/Significance: Elranatamab (ELRA) is a humanized bispecific antibody that targets both B-cell maturation antigen (BCMA)-expressing multiple myeloma (MM) cells and CD3-expressing T-cells. ELRA is currently approved for the treatment of relapsed/refractory MM (RRMM) in several countries. The primary objective of this analysis is to understand the treatment/dosing patterns of ELRA in a real world (RW) setting.
Materials and Methods/Case Presentation/Objective: ALTITUDE-1 (EUPAS1000000229) is an ongoing, non-interventional database study designed to capture real-world ELRA use among patients with MM. The data source is Komodo Health's Healthcare MapTM, which integrates both open- and closed-claims databases from ≥150 public and private payers/insurers as well as clearinghouses across the United States. Adult (≥18 years) patients with MM who had at least one claim for ELRA and had at least 180 days of continuous closed medical and pharmacy claims enrollment prior to their first ELRA claim (defined as the index date) were included in the analyses. Patients with a prior claim for a BCMA bispecific antibody were excluded. This interim analysis, based on the August 2024 data cut (representing a median of 49 days on therapy [range = 0-378]), descriptively reported the treatment patterns of ELRA separately for the following three periods: 1) Index to Day 7 (representing the step-up dosing [SUD] period), 2) Day 8 to Day 168 (representing maintenance period 1 [MP1], in which ELRA would be expected to be administered QW), and 3) Day 169+ (representing maintenance period 2 [MP2], in which ELRA could be administered Q2W, depending on individual patient response).
Results/Description/Main Outcome Measures: 59 patients were included with a median [interquartile range (IQR)] age of 74 [63.0-78.5] years. Patients were 47.5% female, 54.2% White, and 23.7% African American; 45.8% were penta-drug exposed, 25.4% had a prior BCMA-directed therapy, and 15.3% had a prior BCMA-directed CAR T-cell therapy. The 59 patients contributed 90 claims of ELRA during the SUD period (1.5 per patient), with administrations occurring a mean of 5.5 days apart (median = 7, IQR = 3.5-7). 52 patients contributed 321 claims of ELRA in MP1 (Days 8-168 post-index). The mean number of days between administrations was 10.3 (median = 7, IQR = 7-13), with nearly a quarter of administrations already occurring on a Q2W cadence during this period. Seven patients contributed 20 claims of ELRA in MP2 (Days 169+ post-index). The mean number of days between administrations was 21.6 (median = 28, IQR = 14-28), suggesting a monthly (Q4W) cadence in some patients. Among the post-SUD administrations with non-missing dose information (N=255), the 44mg vial was used in 12.5% of these claims. At any point during the post-index period, 72.9% received antivirals, 49.2% received antibiotics, 22.0% received antifungals, and 40.7% received intravenous immunoglobulin (IVIG).
Conclusions: This is the first RW analysis of ELRA using claims data of patients with heavily pretreated MM with nearly a third previously treated with a BCMA directed therapy. ELRA was administered less frequently with early Q2W, and even Q4W, dosing schedules observed. Continued analyses with larger sample sizes and longer follow-up are ongoing.
