Abstract B83: Survival of ethnic and racial minority patients with multiple myeloma treated with first-generation immunomodulatory and proteasome-inhibiting medications

Abstract

Abstract Introduction: Survival for patients with multiple myeloma has increased in the early 21st century. However, population-based studies have suggested that patients of minority ethnic and racial background may not have benefited as much as non-Hispanic white patients. It has been hypothesized that the newer medications may not be as effective in minority patients as in non-Hispanic whites. Methods: To test this hypothesis, we examined survival in patients participating in clinical trials for registration of one of the newer medications with the FDA. In order to minimize the impact of prior therapy and differences in hematopoietic stem cell transplantation rates, only trials examining outcomes in patients with newly diagnosed multiple myeloma who were transplant ineligible were included. Because clinical trial participation by people of minority ethnic or racial background is low, race/ethnicity was categorized as “non-Hispanic white” (nHW), “Asian/Pacific Islander” (API), and “other race/ethnicity.” People of Hispanic ethnicity were included in the “other race/ethnicity” category regardless of race. Results: Five studies involving treatment of newly diagnosed myeloma patients were identified, with a total of 3,407 subjects treated. Four of these trials examined outcomes for patients receiving immunomodulatory drugs (thalidomide and lenalidomide); one examined outcomes for patients receiving bortezomib. Participation by minorities in individual trials ranged from <1% to 17%. Asian/Pacific Islanders were more likely to have high ISS stage and less likely to have favorable cytogenetics compared to other ethnic and racial groups. Non-Hispanic whites were slightly older compared to other ethnic groups (72.0 years for nHW versus 69.5 for API and 69.0 for others). Patients of API background had a numerically slightly higher risk of mortality (hazard ratio of 1.15) compared with non-Hispanic whites after stratification for treatment and study, but the difference was not statistically significant (p=0.28). Patients of other ethnic and racial backgrounds had a lower risk of mortality with a hazard ratio of 0.76 (p=0.03) after stratification for treatment and study and 0.78 (p=0.05) after additional stratification for stage. Conclusions: We conclude that the efficacy differences in treatment between races are minor and do not account for the differences in survival observed in population-based studies. People of minority race or ethnicity other than API with myeloma showed better survival in clinical trials, despite lower survival on the population level for most minorities. Other factors such as access to care may explain the observed population level differences. Citation Format: Elizabeth Dianne Pulte, Lei Nie, Nicole Gromley, Kirsten Goldberg, Amy McKee, Ann Farrell, Richard Pazdur. Survival of ethnic and racial minority patients with multiple myeloma treated with first-generation immunomodulatory and proteasome-inhibiting medications [abstract]. In: Proceedings of the Tenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2017 Sep 25-28; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2018;27(7 Suppl):Abstract nr B83.