Disparities in the use of checkpoint inhibitors and CAR T-cell therapy: A systematic review.
Authors: Jutagir Devika R. , Espinosa Adriana , Lopez Melissa , Rasool Burha , Gomez Taisha , Brown Alexis , Frankel Caitlin A. , Loo Kimberly , Goldberg Johanna , Wolchok Jedd D. , Gany Francesca 
Published: June 2021

e18541 Background: With increasing numbers of newly approved cancer immunotherapy regimens, research is needed to understand whether these costly treatments are equally used by all patients who could benefit from them. The aim of this systematic review was to identify variables linked to whether patients diagnosed with cancer were treated with checkpoint inhibitors and chimeric antigen receptor (CAR) T-cell therapy. Methods: Using the PICO (Patient, Intervention, Comparison, Outcome) framework, we conducted a systematic review searching Medline (New PubMed), Embase.com, and the Cochrane Library (Wiley) for papers published in English between January 1, 1997 and July 27, 2020. Inclusion criteria were: 1) primary, peer-reviewed research article; and 2) article reported variables associated with whether patients were treated with checkpoint inhibitors or CAR T-cell therapy. Seven coders independently reviewed titles, abstracts, full texts, and extracted data. The systematic review adhered to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Results: In total, 5958 titles and abstracts and 134 full texts were screened. Sixteen studies were included in final analyses. All were conducted in the United States using data from national databases (N = 15) or electronic medical records (N = 1). Eleven were cross-sectional, and 5 were cohort studies. Studies looked at melanoma (N = 10), non-small cell lung cancer (N = 3), renal cell carcinoma (N = 2), colorectal cancer (N = 1), prostate cancer (N = 1), and hepatobiliary cancer (N = 1). Studies looked at nivolumab (N = 1), pembrolizumab (N = 1), ipilimumab (N = 1), and sipuleucel-T, (N = 1), and 12 studies did not specify medication names. Treatment facility characteristics (N = 9), geographic location within the United States (N = 1), locale classification (N = 2), distance to treatment facility (N = 2), insurance type (N = 9), age (N = 7), race (N = 5), sex (N = 1), income (N = 4), neighborhood educational attainment (N = 2), comorbidities (N = 6), disease stage (N = 1), metastases (N = 3), clinical trial participation (N = 1), recency of diagnosis (N = 2), other treatments received (N = 3), and lesion characteristics (N = 1) were reported to be associated with whether patients were treated with checkpoint inhibitors or CAR T-cell therapy. Other studies found that insurance type (N = 1), race (N = 3), sex (N = 1), other treatments received (N = 1), and lesion characteristics (N = 1) were not associated with receiving checkpoint inhibitors or CAR T-cell therapy. Conclusions: Findings provide evidence of disparate access to checkpoint inhibitors and CAR T-cell therapy. More studies are necessary to thoroughly understand how the factors highlighted in our findings intersect to create and maintain disparities in cancer treatment. This level of information is necessary to create interventions that promote equitable access to novel cancer immunotherapies.