Geographic Variations in Biologic Therapy and Disease Characteristics: A Pilot-Study in the Corrona Psoriasis Registry

November 2020 | Volume 19 | Issue 11 | Editorials | 1119 | Copyright © November 2020


Published online October 23, 2020

Clinton W. Enos MD,a Katie A. O’Connell MS,a Ryan W. Harrison MS,b Robert R. McLean DSc MPH,b Blessing Dube MPH,b Abby S. Van Voorhees MDa

aEastern Virginia Medical School Department of Dermatology, Norfolk, VA
bCorrona, LLC, Waltham, MA

Abstract
The American Academy of Dermatology and the National Psoriasis Foundation recently published extensive guidelines for the management of psoriasis with biologics.1 However, little is known about geographic variation in the use of these medications. The Corrona Psoriasis Registry is a prospective, multi-center, non-interventional registry for patients with psoriasis under the care of a dermatologist with sites across the United States (Figure 1a). Here, in a pilot analysis of 2018 Corrona data, we investigated geographic variations, based on US Census Divisions, in biologic use by class and patient disease characteristics.

There were 2896 newly enrolled patients on biologic therapy in 2018: 1691 initiated biologic therapy at/after enrollment (initiators) and 1205 had started biologic treatment up to 12-months prior to enrollment (prevalent users). Of the newly enrolled, 24.5% were in the Northeast (NE), 14.4% in East North Central, 11.9% in Mountain-West North Central, 17.8% in South Atlantic, 10.7% in East South Central (ESC), 9.5% in West South Central (WSC), and 11.2% in Pacific (Table 1). Mean age was 50.1 (SD=14.6) and the majority were Caucasian (80.0%), utilized private insurance (73.8%), and had BMI >30 kg/m2 (52.6%). The most frequently reported comorbid diseases were hypertension (38.2%), hyperlipidemia (27.0%), and diabetes mellitus (16.4%). Mean duration of psoriasis was 14.3 (SD=13.1) years. Moderate disease by Body Surface Area (BSA, 3–10%) was the most commonly reported severity level (41.9%). 44% of patients starting therapy were biologic naïve.

Among geographic divisions, the ESC division had one of the highest frequencies of obesity (58.8%) and the largest frequencies of current smokers (24.5%), hypertension (44.8%), hyperlipidemia (33.2%), and diabetes mellitus (23.9%). The ESC also had the greatest frequency of very severe disease (BSA >20%) (22.6%) and the lowest proportion of biologic naïve patient drug starts (36.1%).

Biologic therapy varied geographically: overall, IL-17 inhibitors (IL-17i) were used the most frequently (44.5%) compared to IL- 12/23i and 23i (35%) and TNF inhibitors (TNFi) (20%). The NE was the only region, overall, that utilized the IL-12/23i and 23i class more than the other classes (Figure 1b). When initiating biologic therapy at/after enrollment, TNFi and IL-17i were proportionally chosen more frequently in the ESC (29.1% and 49.8%, respectively) compared to the remaining census divisions; while the IL-12/23i and 23i were more frequent in the NE (48.9%) (Figure 1c). When considering those entering the registry as a prevalent user, the Pacific had the largest proportion on TNFi (35.9%), the ESC on IL-12/23i and 23i (42.5%), and the WSC on IL-17i (55.8%) (Figure 1d).

Limitations to this study are that the Corrona registry is not a random, population-based, representative sample; the registry cohort is comprised of patients invited to participate in the registry by their dermatologists. Regions are derived from the practice location, not patient home addresses. Some regions are underrepresented compared to others, and participating sites may not represent the true overall region.

Despite these caveats, little is known regarding the presence of geographic trends in both the use of biologics for psoriasis and the potential impact on patient outcomes.2-4 The unadjusted analyses here suggest that in the US there are geographic variations in the use of biologic classes for the treatment of psoriasis. Interestingly, there were also geographic differences in psoriasis severity and prevalence of associated metabolic comorbid diseases. In support of these findings, we previously identified hot-spots of moderate-to-severe and severe psoriasis in the ESC among respondents to the 2016/2017 National Psoriasis Foundation Annual Surveys using geographic information systems.5 This geographic trend is strengthened with the known relationship between psoriasis severity and metabolic syndrome6 and the fact that the southern region of the US is burdened with a high prevalence of diabetes and metabolic disease.7-8 How geographic variations in treatment patterns and disease characteristics ultimately impact patient outcomes will be a topic of future research. The Corrona Psoriasis Registry provides a unique opportunity to investigate these real-world trends.