Evaluation of Functional and Cytogenetic High-Risk Multiple Myeloma Using Real-World Data

Introduction: Multiple myeloma (MM) is a heterogeneous disease with wide variability in outcomes. The presence of cytogenetic abnormalities in MM is of critical importance for prognosis and risk stratification. However, patients who may or may not have sufficient cytogenetic abnormalities to classify as high-risk can still experience rapid disease progression despite therapy, or functional high risk (FHR) disease. These two high risk cohorts comprise vulnerable subpopulations who have a significant burden of disease, and it is critical that we understand the underlying patient characteristics and optimal treatment sequence. We sought to investigate these two high risk patient populations treated in the contemporary real-world practice setting.

Methods: A total of 1719 patients were identified in the COTA real-world database as having been diagnosed with active MM on or after January 1, 2015 and classified as either FHR, cytogenetic high risk (CHR), or both. The COTA real-world database is a USA-based real-world evidence database comprised of longitudinal, Health Insurance Portability and Accountability Act (HIPAA)-compliant, data on the diagnosis, clinical management, and outcomes of patients with cancer. Of the 1719 patients, 1260 were identified to be FHR, defined as relapse <18 months from initial active MM diagnosis. A total of 459 patients were identified as CHR, among which 347 were both FHR and CHR. CHR was defined as a patient having at least one of the following abnormalities: t(4;14), t(14;16), t(14;20), del(17p), 1q gain, or hypoploid. Line of therapy was applied programmatically using an algorithm based on International Myeloma Working Group criteria and clinical guidance. The primary outcome was time to next treatment (TTNT) calculated using the Kaplain Meier method. Univariate and multivariate analyses were conducted to understand predictors of rapid disease progression among high-risk patients.

Results: In our real-world population, FHR patients tended to be slightly younger, African American, and treated predominantly in the academic setting (Table 1). First-line (1L) and second-line (2L) treatment patterns by category are shown in Table 2. A lower proportion of FHR patients received 1L immunomodulators as compared to the other high-risk groups, while almost half of the CHR patients received 1L stem cell transplant (SCT). In 2L, among patients not receiving 2L SCT, a higher proportion of CHR patients received a daratumamab-based treatment as compared to FHR (23.2% vs. 12.0%, respectively). We observed a longer median (95% CI) TTNT for high-risk patients receiving 2L daratumamab-based treatment as compared to patients who did not: 8.5 months (6.4-13.0) vs. 6.0 months (5.3-6.9), p=0.07 (Figure 1). Univariate and multivariate analyses showed age at diagnosis (HR: 0.98, CI: 0.97, 0.99), normal cytogenetics (HR: 0.78, CI: 0.63, 0.97), 1L immunomodulator (HR: 0.39, CI: 0.22, 0.69), 1L proteasome inhibitor (HR: 1.4, CI: 1.1, 1.8), and 1L SCT (HR: 0.22, CI: 0.15, 0.32) as significant predictors of rapid disease progression.

Conclusions: Our study provides important insights comparing high risk populations with MM treated in the real-world setting. A higher proportion of CHR patients received 1L SCT and this provided the longest 1L TTNT as compared to other treatments. In 2L, among patients not receiving 2L SCT, we observed a trend towards significantly longer TTNT provided by dara-based treatment as compared to non-dara based treatment; however, our TTNT is lower than progression-free survival results observed in pivotal trials. We identified potential underlying differences in our patient populations that may be driving the predictors of rapid disease progression, including 1L SCT eligibility and renal disease, and these will be further investigated in propensity score matched populations. Future research will continue to explore optimal treatment sequences in high-risk populations with multiple myeloma to improve patient outcomes. These data highlight an urgent need to better predict FHR patients at diagnosis and develop clinical trials incorporating novel compounds in high risk patients.

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