(PA-430) Recent Trends in Real-World Frontline Treatment Patterns and Outcomes for Patients with Multiple Myeloma in the United States

Introduction:  The treatment landscape for multiple myeloma (MM) has rapidly evolved since the approval of daratumumab (DARA) in frontline (1L). While the efficacy of DARA was established in clinical trials, evidence on its real-world effectiveness is still emerging. This study describes the trends of 1L DARA utilization in recent years and its impact on outcomes among patients (pts) with MM in the real world.

Methods:   A retrospective cohort study of adults initiating 1L for MM between 1/1/2015 and 5/31/2024 was conducted using the Flatiron Health Research Database. Time to next treatment (TTNT) was evaluated using Kaplan-Meier analyses. Results were reported separately for pts who received stem cell transplant (SCT cohort) and pts who did not receive transplant (non-SCT cohort). Results were stratified by use of DARA, race (Black or non-Black) and cytogenetic risk (standard or high risk, among pts with known risk).

Results:   In the SCT cohort (n=1,757), median age at 1L initiation was 63 years and 44% of pts were female; in the non-SCT cohort (n=6,559), median age was 72 years and 47% were female. Use of DARA increased steadily since its approval, both in the SCT cohort (2019: 4%; 2020: 11%; 2021: 31%; 2022: 58%; 2023-24: 70%) and the non-SCT cohort (4%; 11%; 22%; 38%; 55%). Use of quadruplet regimens also increased between 2019 and 2023-24 (SCT cohort: 4%; 11%; 30%; 56%; 69%, non-SCT cohort: 2%; 8%; 14%; 25%; 41%).
In the SCT cohort, median TTNT was not reached for DARA users (n=332) compared to 47 months (mos) for DARA non-users (n=1,425). Proportions of pts still on 1L at 48 mos were 58% and 49%, respectively. In the non-SCT cohort, median TTNT was 23 mos for DARA users (n=1,059, 35% on 1L at 48 mos) and 12 mos for non-users (n=5,500, 19% on 1L at 48 mos).
Approximately 21% (62/289) of Black pts in the SCT cohort and 16% (197/1,248) of Black pts in the non-SCT cohort received DARA. In the SCT cohort, the proportion of Black pts still on 1L at 48 mos was higher among DARA users than non-users (70% vs. 49%, respectively). This was also observed in the non-SCT cohort (DARA users: 30%, non-users: 24%).
In pts with standard cytogenetic risk, the proportion of pts still on 1L at 48 mos was higher in DARA users than non-users in the SCT cohort (65% [n=218] vs. 53% [n=919], respectively) and the non-SCT cohort (DARA users: 40% [n=613], non-users: 21% [n=3,165]).
In pts with high cytogenetic risk, the proportion of pts still on 1L at 48 mos was higher in DARA users than non-users in the SCT cohort (31% [n=60] vs. 27% [n=244], respectively) and the non-SCT cohort (DARA users: 20% [n=155], non-users: 10% [n=671]).

Conclusions:   Use of DARA as 1L treatment for MM steadily increased since its approval, which resulted in real-world improvements in TTNT. The TTNT benefit was higher among DARA users than non-users, regardless of SCT status and cytogenetic risk. These findings confirm the translation of clinical trial findings in the real-world practice and supports the use of DARA in 1L.