A systematic review of racial disparity in pivotal poly (ADP-ribose) polymerase (PARP) inhibitor trials.

Abstract

e13737 Background: Breast cancer is the most common cancer diagnosed worldwide. Breast cancer related mortality has decreased in the US, however this did not extend equally to African American women (AAW). According to CDC mortality rate from breast cancer in AAW is 20% higher than other ethnic groups. Younger age at diagnosis in AAW, higher incidence of triple negative breast cancer (TNBC), and higher incidence of AA males with breast cancer suggest genetic predisposition plays an important role in the disparate outcomes based on race. In an unbiased analysis of TNBC cases, the prevalence of pathogenic germline BRCA 1 & 2 mutations are twice as high as in breast cancer overall. Poly (ADP-ribose) polymerase (PARP) inhibitors have proven to be effective in germline BRCA 1 and BRCA 2 mutation associated breast cancer. However, data regarding the enrollment of racial and ethnic minorities in these pivotal trials that lead to the approval of these drugs is limited. Methods: We examined the demographic data reporting in Phase II/ III clinical trials of PARP inhibitors in breast cancer from 2016 to 2023. In order to highlight the disparities in the enrollment of minority groups we calculated an enrollment percentage of various racial groups in these trials. We conducted a systematic review of Phase II/III clinical trials of PARP inhibitors in BRCA 1 & 2 mutated breast cancer reported studies with sources from PubMed, Embase, Scopus, Clinicaltrials.gov, CENTRAL and Cochrane. 56 full text studies were identified, out of which 14 met inclusion criteria. The total number of patients included was N=5,067. Five trials did not include racial data. Results: Among trials that reported race and ethnicity (N=4004), the enrollment percentage was lowest for racial and ethnic minorities. AA: 3.4%, N=136. Non- Hispanic Whites were the most common to be enrolled: 71.05%, N=2845, Asians were 16.53% N= 662, Hispanics 2.03 %; N=83 and other 6.17%, N=247. Conclusions: Racial minorities are consistently underrepresented in all the pivotal PARP inhibitor trials and contributing to the race-based disparities in breast cancer. [Table: see text]