Patwardhan, Pallavi

Introduction: Adverse events (AE), such as cytokine release syndrome (CRS) and neurological toxicity (NT), have been associated with chimeric antigen receptor (CAR) T cell therapies. Idecabtagene vicleucel (ide-cel, bb2121), a B-cell maturation antigen-directed CAR T cell therapy, demonstrated deep and durable responses in triple-class exposed (TCE) patients (pts) with RRMM in the pivotal, single-arm, open-label phase 2 KarMMa (3 prior lines of therapy [LOTs]; NCT03361748) (Munshi NC, et al. NEJM 2021;384:705-716) and superior progression-free survival with ide-cel vs standard regimens in the phase 3 KarMMa-3 trial (2-4 prior LOTS; NCT03651128) (Rodríguez-Otero P, et al. NEJM 2023;388:1002-1014). Healthcare resource utilization (HCRU) and costs associated with CRS/NT management were estimated previously for pts receiving ide-cel in the KarMMa trial (McGarvey N, et al. Value Health 2023;26:S89) and suggested low rates of severe (grade ≥ 3) CRS/NT following ide-cel infusion and higher HCRU and costs with increasing AE severity. To further assess resource and economic burden associated with care of treatment-emergent AEs, this analysis evaluated HCRU and estimated cost of CRS/NT management among pts treated with ide-cel in earlier-line settings in the KarMMa-3 study. Methods: In this retrospective study, case report forms from the KarMMa-3 clinical trial database among pts experiencing a CRS and/or NT event that initiated within 90 days post ide-cel infusion were assessed. Pt-level HCRU data, including hospitalizations and length of hospital stay (LOS) (standard inpatient [IP], intensive care unit [ICU] days), diagnostics (eg, lab work, imaging), procedures (eg, dialysis, intubation), and medications (eg, oncology supportive care, prophylactics, other AE management) were identified from CRS/NT onset through resolution. AE management costs were estimated using a micro-costing methodology in which unit costs sourced from public databases or literature (eg, United States Centers for Medicare and Medicaid Services, Healthcare Cost and Utilization Project, IBM ® Micromedex ® RED BOOK ®) were adjusted to 2022 US dollars (USD) using the Consumer Price Index and applied to each HCRU identified. Results: Of 225 pts treated with ide-cel in the KarMMa-3 trial, 203 (90.2%) experienced any grade CRS and/or NT event. Pts experiencing a CRS/NT event had a mean (standard deviation [SD]) age of 61.9 (8.9) years and most were male (123/203 [60.6%]), White (138/203 [68.0%]), and non-Hispanic or Latino (138/203 [68.0%]). The majority (187/203 [92.1%]) of pts experienced less severe CRS/NT events (grade ≤ 2), which resolved quicker and relatively few pts (16/203 [7.9%]) had a more severe (grade ≥ 3) event, which took longer to resolve. Among pts who received ide-cel, the estimated median cost of AE management ranged from USD 17,124 (CRS only grade 1) to USD 181,552 (nonconcurrent CRS or NT grade ≥ 3) (Figure 1). Additional median costs for a pt with a grade ≥ 3 CRS/NT event was USD 31,045 higher than a grade ≤ 2 CRS/NT event. Across AE categories, the main contributors to CRS/NT management were facility costs, namely standard IP hospitalizations and ICU stays. Almost all pts (202/203 [99.5%]) had a standard IP hospitalization; 3.9% (8/203) had an ICU stay (Table 1). The trial protocol required a stay of ≥ 15 days post infusion unless admitted to the ICU; some hospitalization days recorded during the AE overlapped with the protocol-required stay. ICU admissions were more common among pts with CRS/NT grade ≥ 3 (7/16 [43.8%]) than those with grade ≤ 2 (1/187 [0.5%]). Median (range) total LOS was 10 days longer among pts with grade ≥ 3 (14.5 [2-84] days) than those with grade ≤ 2 (4 [1-34] days) CRS/NT. Pts with grade ≥ 3 CRS/NT had higher rates of HCRU than those with grade ≤ 2 for several interventions, such as medications (eg, tocilizumab + corticosteroids: 13/16 [81.3%] vs 63/187 [33.7%]), diagnostics (eg, imaging: 14/16 [87.5%] vs 48/187 [25.7%]), and procedures (eg, dialysis:3/16 [18.8%] vs 0/187 [0%]). Conclusions: Most pts with RRMM treated with ide-cel in the KarMMa-3 trial experienced a CRS and/or NT event, however, few were of high severity (grade ≥ 3). HCRU and costs for CRS/NT increased with AE severity and management. CAR T cell therapies associated with lower-severity AEs and planned interventions to prevent higher-grade AEs may provide an opportunity to better manage HCRU and costs.

Introduction: With rapid treatment advances in multiple myeloma (MM), more patients receive the 3 main classes of MM treatments (immunomodulatory imide drug [IMiD] agents, proteasome inhibitors [PIs], and anti-CD38 monoclonal antibodies [mAbs]) in earlier lines of therapy and become TCE. This is a prerequisite for subsequent treatment with some novel therapies eg, anti-B-cell maturation antigen (BCMA) agents. Published evidence of RW clinical outcomes in patients with TCE MM is scarce in the evolving RRMM treatment landscape. The objective of this study was to assess RW clinical outcomes in patients with TCE RRMM who received treatment post-TCE. Methods: In this observational study, we analyzed de-identified patient data derived from electronic health records (EHRs) from 2 key United States (US) MM longitudinal databases (Flatiron Health MM [FHMM] and COTA Vantage MM [CVMM]). We identified patients who became TCE between November 2015 and March 2021 and received a subsequent treatment post-TCE; the earliest available end date of the 3rd treatment class was considered the date patients became TCE. The start date of the 1st treatment post-TCE (index treatment) was defined as the index date. We analyzed patient demographics, disease characteristics, prior treatment exposure, refractory status, and index treatments patterns/classes. Clinical endpoints assessed were response rates (overall and complete), overall survival (OS), progression-free survival (PFS), and time to progression (TTP). Results: The FHMM and CVMM databases included 1,319 and 1,118 TCE patients, respectively, of whom 897 and 795 received an index treatment post-TCE. Median (range) follow-up for patients who received an index treatment was 18.1 (0.1-82.0) and 15.5 (0.03-72.3) months for FHMM and CVMM cohorts, respectively. Median age for both RW cohorts was 68 years, more than half of patients were men and the majority were White. Patients received a median of 3 lines of prior treatment (range, 1-14 and 1-12 for FHMM and CVMM cohorts, respectively). In both RW cohorts, >75% of patients who received an index treatment were triple-class refractory and approximately 10% were penta-refractory, having received treatment with 2 IMiD agents, 2 PIs, and an anti-CD38 mAb. Approximately 67% and 79% of patients in the FHMM and CVMM cohorts, respectively, had ECOG performance status 0 or 1. Approximately 54% and 61% had received prior stem cell transplantation. IMiD agents either alone or in combination with a PI and/or anti-CD38 mAb constituted the main regimens for index-treated patients. In the CVMM cohort, the overall and complete response rates were 15.2% and 1.7%, respectively; response data were not available in the FHMM cohort. Median OS (22.3 and 20.4 months), median PFS (4.8 and 4.9 months), and median TTP (5.9 and 5.9 months) were comparable for both FHMM and CVMM cohorts. Conclusions: In this observational cohort study of 2 US RW EHR databases, patients became TCE with a median of 3 prior lines of therapy. Post-TCE, most patients with RRMM still received the same 3 treatment classes with poor response and survival outcomes on their treatments. Despite advances in MM management, this study highlights the need for more efficacious novel treatments for patients with TCE MM and serves as a RW benchmark in the literature for appraising emerging data from novel agents in patients with RRMM.