Frontline Treatment Patterns in Patients with Newly Diagnosed Multiple Myeloma - Real-World Evidence from a Large Community-Based Oncology Practice Network in the US

Introduction: The treatment landscape for newly diagnosed multiple myeloma (NDMM) is evolving. Given that community oncology clinics treat the majority of patients (pts) with NDMM, it is critical to understand the frontline (1L) treatment patterns in this setting. This study aimed to describe the pt characteristics, treatment patterns, and outcomes of pts with NDMM who received 1L treatment at a clinic within a large community oncology practice network in the US.

Methods: A sample of 1,000 adult pts with NDMM who initiated 1L treatment between January 2018 and October 2022 were randomly selected from the Florida Cancer Specialists and Research Institute’s (FCS) electronic medical record (EMR) database. Pts with invasive malignancies or stem cell transplant (SCT) on or before 1L initiation were excluded. Baseline characteristics were captured at index date. Duration of treatment (DOT) and time to next treatment (TTNT) were calculated using Kaplan Meier analyses. Treatment discontinuation was defined as a gap >90 days for pts without SCT and a gap >183 days for pts with SCT in 1L. Because SCT is not captured in the structured EMR data, a chart review was conducted in a subset of 500 pts (all pts receiving daratumumab-based regimens and a random sample of pts receiving VRd) to avoid misclassifying the treatment gap during SCT as discontinuation.

Results: From the selected pt sample, 881 pts met the study eligibility criteria. Among these, 70.7% pts received triplets, 17.8% received monotherapy or doublets, and 11.4% received quadruplets (quads) during the study period. The median age of pts receiving doublets (79.0 years) was higher than those receiving triplets (73.0 years) and quads (70.0 years). Among pts receiving quads, 65.0% were male and 28.0% had high cytogenetic risk (HCR; presence of del17p, t[14;16], t[4;14], gain or amp 1q21; a higher proportion than in pts receiving triplets/doublets), while among pts receiving doublets, 36.9% were frail (a higher proportion than in pts receiving triplets/quads). Among the 1L regimens, 81.3%, 79.7%, and 22.8% contained proteasome inhibitors, immunomodulatory agents, and monoclonal antibodies (mAb), respectively. Most common 1L regimens observed during this period were bortezomib (V)+lenalidomide (R) + dexamethasone (d) (VRd; 50.3%), daratumumab (D) + VRd (DVRd; 8.9%), Rd (7.9%), cyclophosphamide (Cy) + Vd (VCyd; 7.0%), and DRd (6.9%). From 2018 to 2022, the use of doublets decreased from 25.8% to 8.7%, while the use of quads increased from 1.9% to 39.1%. Use of VRd decreased from 59.4% in 2018 to 27.5% in 2022, and the use of mAb-based regimens (mostly daratumumab-based regimens) increased from 3.2% in 2018 to 58.0% in 2022. Of the 319 pts that were selected for chart review and met the criteria for further analysis, 66 received DVRd (21 with SCT; 45 without SCT), 47 received DRd (1 with SCT; 46 without SCT), and 206 received VRd (27 with SCT; 179 without SCT). Due to a small number of pts with SCT, results are only presented for pts who did not receive SCT in 1L. Pts treated with DRd in 1L were older with a median age of 81.0 years compared to those treated with DVRd (70.0 years) and VRd (75.0 years). A greater proportion of pts receiving VRd were Black (14.0%) compared to DVRd (8.9%) and DRd (6.5%). About 69.6% of pts receiving DRd were frail (a higher proportion than in pts receiving DVRd and VRd) and 44.4% of DVRd pts were HCR (a higher proportion than in pts receiving DRd and VRd). Among pts receiving DRd, DVRd, and VRd, the median follow-up was 23.3 months, 15.3 months, and 25.9 months; the median DOT was 19.9 months (95% CI: 6.1-NR), 15.0 months (95% CI: 4.2-23.2), and 6.5 months (95% CI: 3.9-25.1); and the median TTNT was 28.0 months (95% CI: 12.2-NR), 17.0 months (95% CI: 8.8-NR), and 12.0 months (95% CI: 5.6-37.8), respectively.

Conclusions: The growing usage of quads and daratumumab-based regimens suggests that treatment patterns in community practices are evolving with the growing body of clinical evidence. While doublet use was still observed among older and frail pts, there was a noticeable increase in usage of 1L DRd in these pts. Daratumumab-based regimens had longer TTNT, even though pts receiving daratumumab-based quads had a higher proportion with HCR. Compared to White pts, fewer Black pts received daratumumab-based regimens. These results indicate that there is an opportunity to further optimize the use of clinically advanced regimens for all NDMM pts.