Annual Trends in Medicare Part D Prescription Claims for Guselkumab, 2018–2020 

Guselkumab is an interleukin-23 inhibitor that prevents the proliferation of T-helper 17 cells.1 It was approved by the US Food and Drug Administration (FDA) for the treatment of plaque psoriasis in 2017 and psoriatic arthritis in 2020.1 Guselkumab and other biologics have changed the landscape of psoriasis management as there are now many approved novel agents.¹ Currently, research is limited in prescription trends among biologic agents such as guselkumab.

We explored the trends of guselkumab prescriptions among the Medicare population utilizing the national 2018 to 2020 Medicare Part D Prescriber datasets. Data from 2017 (year of FDA approval) was not included as there were a limited number of clinicians with at least 11 annual claims. We assessed the characteristics, clinical settings, and practice types among prescribers with at least 11 annual claims of guselkumab using the provided National Provider Identifier (NPI). Information of prescribers with less than 11 annual claims of guselkumab were not provided in the database.

Among the Medicare population, total claims for guselkumab have increased at an average annual rate of change of 40.2% from 2018 to 2020 (Table I). The rising number of total claims has resulted in an increase in the total cost of claims from $77.1 million in 2018 to $167.4 million in 2020 (average annual rate of change of 47.4%) (Table I). The majority of guselkumab prescribers are dermatologists (76.1%), located in metropolitan areas (92.1%), and are not sole proprietors (77.8%) (Table II). Despite dermatologists being the majority of guselkumab prescribers, there has been an average annual growth rate of 112.6% and 126.6% among advanced practice providers (APPs) and non-dermatology physicians, respectively (Table II). 

Previously, Dean et al. discussed the rapid rise in Medicare Part D claims (2017 to 2018) for guselkumab.² Our findings further support this conclusion and elucidate more recent trends and characteristics of prescribers. Our findings indicate a growth in guselkumab claims over time, especially among APPs and non-dermatology physicians, which may be in part due to data revealing long-term safety and efficacy of the drug and recent approval for psoriatic arthritis.¹ The minimal number of prescribers of guselkumab in non-metropolitan areas may reflect the limited access to dermatologic care in these areas.³ Increasing the number of practitioners and access to care in these areas may provide increased accessibility to biologic agents for psoriasis patients. Drugs for the management of psoriasis, especially biologics, constitute a significant proportion of Medicare Part D spending for dermatologists.⁴ As many Medicare patients are faced with difficulty obtaining coverage for biologics, evaluating prescription trends among this population may provide insight about which geographic regions and prescribers have the most success for Medicare Part D coverage of guselkumab.⁵

Limitations of our study include the inability to extract data for prescribers with less than 11 annual claims and lack of generalizability to non-Medicare patients. Future studies are needed to compare the prescription trends of guselkumab to other systemic or biologic agents for psoriasis management. 

1. Yang K, et al. Use of IL-23 Inhibitors for the Treatment of Plaque Psoriasis and Psoriatic Arthritis: A Comprehensive Review. Am J Clin Dermatol. 2021;22(2):173-192. Doi:10.1007/s40257-020-00578-0

2. Dean O, et al. Adoption of newly FDA-approved targeted immunomodulatory therapies by dermatologists: a cross-sectional analysis of Medicare Part D claims from 2013 to 2018. Arch Dermatol Res. 2022. Doi:10.1007/s00403-022-02422-3.

3. Vaidya T, et al. Socioeconomic and geographic barriers to dermatology care in urban and rural US populations. J Am Acad Dermatol. 2018 Feb;78(2):406-408. doi: 10.1016/j.jaad.2017.07.050

4. Yang JJ, et al. Psoriasis drugs in the medicare population: dermatologists’ spending and prescription patterns. J Dermatol Treat. 2022 May;33(3):1758-1761. Doi:10.1080/09546634.2020.1864265

5. Natsis NE, et al. Treatment of Medicare Patients with Moderate-to-Severe Psoriasis who Cannot Afford Biologics or Apremilast. Am J Clin Dermatol. 2020 Feb;21(1):109-117. Doi: 10.1007/s40257-019-00468-0