Real-world multiple myeloma risk factors and outcomes by non-Hispanic Black/African American and non- Hispanic White race/ethnicity in the United States

Abstract

Examination of the impact of race and ethnicity on multiple myeloma (MM) outcomes has yielded inconsistent results. This retrospective, real-world (RW) study describes patient, disease, and treatment characteristics (and associations with survival outcomes) among newly diagnosed MM patients of non-Hispanic (NH) Black/African American (AA) and NH White race/ethnicity in the US. We included patients from the nationwide Flatiron Health electronic health record-derived de-identified database who initiated first line of therapy (LOT) for MM between January 1, 2016 and March 31, 2022. Of 4,614 patients in our study cohort, 23.3% were NH Black/AA. Non-Hispanic Black/AA patients were younger than NH White patients at diagnosis (median 68 vs. 71 years) and more likely to be female (53.4% vs. 43.5%). Rates of high-risk cytogenetics and 1q21+ were similar between races/ethnicities. The most common primary regimen used was lenalidomide-bortezomib-dexamethasone (50.1% of NH Black/AA and 48.1% of NH White patients). Receipt of stem cell transplantation during first LOT was less common among NH Black/AA (16.5%) than NH White (21.9%) patients. Unadjusted RW progression-free survival (rwPFS) and overall survival (rwOS) were similar between races/ethnicities. After multivariable adjustment, NH Black/AA race/ethnicity was associated with slightly inferior rwPFS (hazard ratio [HR]=1.13; 95% confidence interval [CI]: 1.01-1.27). The difference in rwOS (HR=1.12; 95% CI: 0.98-1.28) was not statistically significant. In general, associations between risk factors for rwPFS and rwOS were consistent between races/ethnicities. Findings from this analysis help to inform clinicians about the impact of race/ethnicity on MM treatment paradigms and outcomes in the US.

Figure 1.

Kaplan-Meier analysis of real-world progression-free survival from start of first line of treatment by race/ethnicity. CI: confidence interval; LOT: line of therapy; rwPFS: real-world progression-free survival.

Figure 2.

Multivariable-adjusted Cox proportional hazards model of real-world progression-free survival from start of first line of treatment, by race/ethnicity, overall and for select subgroups. *High-risk cytogenetics were defined as the presence of ≥1 of del(17p), t(4;14), or t(14;16). ^†1q21+ was defined as gain (3 copies) or amplification (≥4 copies) of 1q21. ‡Assessed using the MDRD equation; expressed as mL/min/1.73 m. CI: confidence interval; ECOG PS: Eastern Cooperative Oncology Group performance status; eGFR: estimated glomerular filtration rate; HR: hazard ratio; ISS: International Staging System; LOT: line of therapy; MDRD: modification of diet in renal disease; MV: multivariable; PS: performance status; rwPFS: real-world progression-free survival.

Figure 3.

Kaplan-Meier analysis of real-world overall survival from start of first line of treatment by race/ethnicity. CI: confidence interval; LOT: line of therapy; NR: not reached; rwOS: real-world overall survival.

Figure 4.

Multivariable-adjusted Cox proportional hazards model of real-world overall survival from start of first line of treatment, by race/ethnicity, overall and for select subgroups. *High-risk cytogenetics were defined as the presence of ≥1 of del(17p), t(4;14), or t(14;16). ^†1q21+ was defined as gain (3 copies) or amplification (≥4 copies) of 1q21. ‡Assessed using the MDRD equation; expressed as mL/min/1.73 m. CI: confidence interval; ECOG PS: Eastern Cooperative Oncology Group performance status; eGFR: estimated glomerular filtration rate; HR: hazard ratio; ISS: International Staging System; LOT: line of therapy; MDRD: modification of diet in renal disease; MV: multivariable; PS: performance status; rwOS: real-world overall survival.