Racial disparities in clinical trials of biologic treatments for psoriatic arthritis
Authors: Samantha Shwe, Cristina Nguyen, Tina Bhutani
Journal: Journal of the American Academy of Dermatology (2021)

To the Editor: Psoriatic arthritis affects 20% to 30% of patients with psoriasis; however, little is known about racial and ethnic differences in prevalence.1Alinaghi F. Calov M. Kristensen L.E. et al.Prevalence of psoriatic arthritis in patients with psoriasis: a systematic review and meta-analysis of observational and clinical studies.J Am Acad Dermatol. 2019; 80: 251-265.e19Abstract Full Text Full Text PDF PubMed Scopus (223) Google Scholar Limited knowledge regarding disease manifestations in non-White races is exacerbated by an underrepresentation of non-White participants in clinical trials.2Reddy V.D. Myers B.A. Chan S.Y. et al.A review of current phase III clinical trials of plaque psoriasis: under-representation of nonwhite participants and need for reform.Br J Dermatol. 2021; 184: 348-350Crossref PubMed Scopus (10) Google Scholar To determine the extent of underrepresentation, a cross-sectional study was performed assessing differences in patient race and ethnicity in completed phase III clinical trials for biologic agents used to treat psoriatic arthritis. A literature search was conducted from September 2020 to April 2021 using PubMed and US National Library of Medicine ClinicalTrials.gov databases. The National Library of Medicine search terms included "psoriatic arthritis" with filters applied for "completed" status, "adult (18-64)" age, and "phase 3" study phase. All human, completed phase III clinical trials in English were included. Trials that did not study a biologic agent or report a comprehensive breakdown of data on race or ethnicity were excluded. A total of 16 clinical trials were included, consisting of 7546 participants treated with 7 biologic agents (Table I). Of these studies, 8 reported both race and ethnicity, 7 reported only race, and 1 reported only ethnicity. Studies reporting both race and ethnicity did not specify ethnicity for each race, but listed Hispanic ethnicity as a separate category. The majority of participants (80.6%) were White. Non-White races included 0.40% Black, 3.56% Asian, 0.61% American Indian, and 0.08% Native Hawaiian/Pacific Islander; 0.45% identified with more than 1 race. Of studies that reported ethnicity, 6.19% of participants were Hispanic. In contrast, the US 2019 demographic data showed a breakdown of 76.3% White, 13.4% Black, 5.9% Asian, and 18.5% Hispanic/Latino (Hispanics may be of any race and were included in applicable race categories).3United States Census BureauACS demographic estimates and housing estimates.2019https://www.census.gov/quickfacts/fact/table/US/PST045219Date accessed: June 14, 2021Google Scholar Although this comparison is limited because of international study enrollment, it may serve as a reference for defining appropriate representation.Table IRace and ethnicity data in clinical trials evaluating biologic treatment of psoriatic arthritisBiologics in evaluated psoriatic arthritis phase III clinical trialsReported race or ethnicityAdalimumab, certolizumab, etanercept, guselkumab, ixekizumab, secukinumab, tofacitinibWhiteBlackAsianAmerican IndianNative Hawaiian/Pacific IslanderHispanic∗Hispanic ethnicity is defined as a person of Cuban, Mexican, Puerto Rican, South or Central America, or other Spanish culture or origin, regardless of race, and may be included in applicable race categories.More than 1 raceOther†Other includes unknown or not reported.Clinical trialn = 6082 (80.60%)n = 30 (0.40%)n = 269 (3.56%)n = 46 (0.61%)n = 6 (0.08%)n = 467 (6.19%)n = 34 (0.45%)n = 612 (8.11%)∗ Hispanic ethnicity is defined as a person of Cuban, Mexican, Puerto Rican, South or Central America, or other Spanish culture or origin, regardless of race, and may be included in applicable race categories.† Other includes unknown or not reported. Open table in a new tab The incidence of psoriatic arthritis ranges from 3.6 to 7.2 per 100,000 person years. Prevalence among patients with psoriasis varies between Europe (22.7%), South America (21.5%), North America (19.5%), Africa (15.5%), and Asia (14.0%).1Alinaghi F. Calov M. Kristensen L.E. et al.Prevalence of psoriatic arthritis in patients with psoriasis: a systematic review and meta-analysis of observational and clinical studies.J Am Acad Dermatol. 2019; 80: 251-265.e19Abstract Full Text Full Text PDF PubMed Scopus (223) Google Scholar Clinical trials may adjust for this and define an appropriate representation in order to include greater proportions of non-Hispanic White patients compared to other races and ethnicities. Nevertheless, percentages of Black and Hispanic participants in this review were significantly lower than percentages of other races and ethnicities. This finding is seen not only in clinical trials for psoriatic arthritis but also in other dermatologic clinical trials (atopic dermatitis and psoriasis), cancer, cardiovascular disease, and COVID-19.2Reddy V.D. Myers B.A. Chan S.Y. et al.A review of current phase III clinical trials of plaque psoriasis: under-representation of nonwhite participants and need for reform.Br J Dermatol. 2021; 184: 348-350Crossref PubMed Scopus (10) Google Scholar Factors that may contribute to the underrepresentation of minorities in clinical trials include lack of training for researchers and staff on the importance of diversity in trials and effective strategies for recruiting and retaining minority populations.4Kusnoor S.V. Villalta-Gil V. Michaels M. et al.Design and implementation of a massive open online course on enhancing the recruitment of minorities in clinical trials—faster together.BMC Med Res Methodol. 2021; 21: 44Crossref PubMed Scopus (6) Google Scholar Table II lists successful strategies published by the NIH for the recruitment and retention of minorities in clinical trials.5US Department of Health and Human Services. Outreach notebook for the inclusion of women and minorities as subjects in clinical research. National Institutes of Health. NIH publication No. 03–7036. Accessed June 14, 2021. https://grants.nih.gov/policy/inclusion/women-and-minorities.htmGoogle Scholar To address racial and ethnic underrepresentation in clinical trials, greater efforts must be devoted to educating and training staff on cultural competency, increasing community involvement and outreach, and adopting a patient-centered approach with resources that cater to the diverse needs of minority populations.Table IIStrategies for recruiting and retaining women and minorities in clinical research5US Department of Health and Human Services. Outreach notebook for the inclusion of women and minorities as subjects in clinical research. National Institutes of Health. NIH publication No. 03–7036. Accessed June 14, 2021. https://grants.nih.gov/policy/inclusion/women-and-minorities.htmGoogle ScholarStrategyExampleInvolve the community•Solicit the support and participation of minority community physicians, community leaders, ministers, and other local organizations for recruiting and retaining study participants.•Develop promotional and educational materials designed to increase awareness in the community.•Establish communication channels that are culturally sensitive and use language appropriate.Involve the participants•Include minority participants in designing the research and preparing study materials to be sure the materials meet needs and expectations of the participants and are culturally and linguistically sensitive.•Create a participant advisory board to give feedback on recruitment forms and study procedures.•Recruit participants to plan social events and coordinate daily tasks associated with running a clinical research investigation.Staff the study team appropriately•Include members of minority groups with the same ethnic or racial background as the target population on the research staff.•Provide pictures of staff in the research setting and include staff pictures in newsletters to facilitate identity and relationships among staff and participants.Address logistical and financial needs•Maximize convenience with extended and flexible clinic hours, multiple site follow ups, and consolidation of protocol visits with existing medical appointments.•Offer childcare and transportation or reimburse patients for these services and their time.•Explore potential of insurance coverage for expenses associated with participation.Improve communication•Provide additional time and assistance to those participants with special needs to review the study's benefits and limits with options for 1:1 exchange of information.•Tailor study materials with consideration of diverse cultural and demographic characteristics.•Use focus groups to identify and understand potential barriers to participation of minority members. Open table in a new tab Dr Bhutani is currently an investigator for Celgene, Galderma, Janssen, and Regeneron and has been an advisor for AbbVie, Lilly, and Pfizer. Authors Nguyen and Shwe have no conflicts of interest to disclose.