Real-World (RW) Treatment (Tx) Patterns and Outcomes in Patients (Pts) with Relapsed/Refractory Multiple Myeloma (RRMM) Previously Treated with Lenalidomide and an Anti-CD38 Monoclonal Antibody: Data from the Japan Medical Data Vision Database
Authors: Kuroda Junya , Acheampong Teofilia , Nakakoji Mayuko , Miyazaki Tohru , Hinosugi Ryosuke , Kuwayama Shigeki , Shih Yu-Hsuan 
Published: December 2024

Introduction:Multiple myeloma (MM) is a malignant plasma cell disorder where most pts eventually relapse or become refractory to available treatments. The use of lenalidomide (LEN) and an anti-CD38 monoclonal antibody (mAb) has been one of the standard tx approaches for both pts with newly diagnosed MM and early RRMM. However, little is known about the subsequent tx patterns and outcomes of pts with prior exposure to LEN + anti-CD38 mAb in a RW setting. RW evidence is essential for understanding the unmet needs and economic burden of this pt population.

Objective: This study evaluated RW tx patterns and clinical characteristics, as well as health care resource utilization (HCRU) and economic outcomes in pts with RRMM previously treated with LEN + anti-CD38 mAb in Japan.

Methods: This retrospective, observational study used the Medical Data Vision database. This database includes inpatient and outpatient claims covering 48 million individuals from acute care hospitals in Japan. Pts with RRMM were eligible if they were ≥ 18 years of age, had ≥ 1 inpatient or 2 outpatient claims on different dates for a diagnosis of MM between April 1, 2008 and December 31, 2023, received prior LEN + anti-CD38 mAb (both in the same or different tx lines), and received a subsequent line of therapy (LOT; index tx) between November 1, 2017 and June 30, 2023. The index date was the start of the index tx regimen. Pts with &lt; 6 months of medical data before and after the index date (except for death) were excluded. Pt characteristics and tx patterns were analyzed using descriptive statistics. Kaplan-Meier curves assessed clinical outcomes from the index date to the duration of therapy (DOT) and time to the next tx (TTNT). Total and MM-related HCRU and costs were reported as averages for the first 6 months post-index and per pt per month (PPPM) during the entire follow-up. Subgroup analyses evaluated outcomes by age (&lt; 65, ≥ 65 years) and index tx at the second line (2L), third line (3L), or fourth line and beyond (4L+).

Results: A total of 1273 eligible pts were analyzed. Median age was 71.0 years (range, 23.0-94.0), 48.5% of pts were male, and 57.8% had a Charlson Comorbidity Index ≥ 3. The median time from MM diagnosis to index date was 39.8 months (range, 2.3-174.9), and the median follow-up period was 14.1 months (range, 0.1-69.6). Overall, 1, 2, 3, and ≥ 4 prior LOTs were received by 16.8%, 28.7%, 23.2%, and 31.3% of pts, respectively. The majority of pts (85.0%) were triple-class exposed before index tx; nearly all pts (94.0%) received daratumumab (DARA) prior to index tx. The most common index regimens after LEN + anti-CD38 mAb were pomalidomide (POM) + dexamethasone (DEX) (7.6%); elotuzumab, POM, and DEX (7.0%); carfilzomib + DEX (6.7%); isatuximab (ISA), POM, and DEX (5.7%); and ixazomib, LEN, and DEX (5.0%). An anti-CD38 mAb (regimen containing either ISA or DARA) was received again by 38.3% of pts as part of the index regimen.

The median DOT was 6.4 months (95% confidence interval [CI], 6.0-7.0), and the probabilities of remaining on the index tx at 6 and 12 months were 53.1% and 33.1%, respectively. The median TTNT was 9.6 months (95% CI, 8.8-10.5) with probabilities of not initiating a subsequent tx at 6 and 12 months being 65.0% and 42.5%, respectively. DOT and TTNT were similar among pts &lt; 65 and ≥ 65 years of age, while DOT and TTNT numerically decreased in pts who started the index tx in a later LOT. Regarding total HCRU resulting from any cause within the first 6 months after initiating the index tx, 49.3% of pts were admitted to the hospital with a median length of stay of 24 days, and 92.7% were evaluated in the outpatient setting (median, 14 visits). The overall mean number of hospitalizations and outpatient visits were 0.2 and 2.4 PPPM, respectively. Most HCRU was MM-related. Overall, the total health care costs resulting from any cause were $10,563 PPPM; 92.5% were MM-related. Pts &lt; 65 years of age or those who started the index tx in 4L+ had numerically higher rates of HCRU and health care costs than those &gt; 65 years of age and those who started index tx earlier.

Conclusions: DOT and TTNT outcomes were suboptimal in pts with RRMM previously treated with LEN + anti-CD38 mAb in Japan. In addition, significant hospitalization rates and MM-related health care costs were shown among these pts, highlighting the high economic burden resulting from RRMM. These data indicate the need for new, effective tx options.