Burden of Hospitalization before and after a Disease Progression Following Triple-Class Exposure in Patients with Relapsed and Refractory Multiple Myeloma

Introduction: Multiple myeloma (MM) is a plasma cell malignancy with various clinical complications. Patients with relapsed and refractory multiple myeloma (RRMM) often suffer from disease progression and cycle through multiple treatments, including those from the same drug classes that they have failed before. Disease progression is usually associated with significant burden, including high health care resource utilization (HCRU) and costs. However, no current known literature quantifies HCRU and costs before and after disease progression in RRMM patients who have been exposed to multiple classes of therapies. This study aims to describe and compare hospitalization use and associated costs before and after disease progression in patients with RRMM who are triple-class exposed (TCE; defined as exposure to a proteosome inhibitor, an immunomodulatory agent, and an anti-CD38 antibody).

Methods: This retrospective cohort study used the Optum Clinformatics^® Data Mart database from 1/1/2012 to 12/31/2021. Adults with ≥2 diagnosis codes for MM (ICD-10-CM: C90.0x) ≥30 days apart and who received a subsequent line of therapy (LOT) after becoming TCE were included. The start of a subsequent LOT after TCE was used as a surrogate to define disease progression, and the initiation date of the latest of such LOTs was defined as the index date if multiple eligible LOTs were observed for the same patient. Patients were also required to have ≥6-month continuous enrollment (CE) in medical and pharmacy plans before and after index. Patient characteristics were described at index and during the 6-month baseline period. A 2-month pre-post analysis was performed to compare all-cause inpatient admissions, intensive care unit (ICU) stays, hospitalization length of stay, and direct inpatient costs. Categorical variables were compared using McNemar’s test, and counts and costs were compared using paired generalized linear models. Subgroup analyses were performed in patients with commercial insurance or Medicare Advantage.

Results: A total of 523 patients met the study criteria. The mean age was 70.2 years, 63.1% were White, 51.2% were female, 72.5% had Medicare Advantage, the mean Quan–Charlson comorbidity index was 4.2, and 34.8% had ≥4 prior LOTs within the CE period containing the index date. The proportion of patients who had an all-cause inpatient admission (20.1% vs 12.8%, P = 0.0008) and an ICU stay (6.5% vs 1.9%, P = 0.0004) were significantly higher during the 2-month post- versus pre-index period. During the 2-month post-index period, patients on average had significantly more all-cause inpatient admissions (0.29 vs 0.16, P <0.0001). The mean inpatient length of stay for the cohort was numerically higher during the 2-month post- versus pre-index period (1.67 vs 1.07 days, P = 0.0751). The mean per-month cost of all-cause hospitalization was significantly higher during the 2-month post- versus pre-index period ($3,590.81 vs $1,267.18, P = 0.0008). The majority of the all-cause hospitalization use and costs (>90%) were MM-related. Similar trends were observed among commercial and Medicare Advantage patients.

Conclusions: This study found a pronounced increase in hospitalization and costs in the 2 months immediately following disease progression in RRMM patients who are TCE. The data may support economic assessment and value framework for innovative treatments with significant prolonged progression-free survival. In addition, there is a need to focus on multifaceted efforts to improve overall well-being and the total cost of care for patients with RRMM.