Literature Review: Psoriasis Carries Hefty Price Tag

Psoriasis is a common, chronic, inflammatory, multisystem disease with predominately skin and joint manifestations. Psoriasis is associated with several comorbidities, including cardiovascular disease, type 2 diabetes, lymphoma, and depression [J Am Acad Dermatol. 2011;65(1):137-174]. There are 5 types of psoriasis: plaque, guttate, inverse, pustular, and erythrodermic; plaque psoriasis is the most common form of the disease. Psoriasis can show up anywhere on the body including the scalp, elbows, knees, and hands and feet. Psoriasis can be mild, moderate, or severe, and can be classified based on the extent of body surface area (BSA) involvement. The National Psoriasis Foundation (NPF) defines mild psoriasis as affecting <3 of BSA, 3% to 10% of BSA is considered moderate, and >10% of BSA is considered severe. NPF data estimates as many as 7.5 million Americans (2.2% of the population) have psoriasis, which usually appears between the age of 15 and 25. Nearly 25% of cases are considered moderate-to-severe.

While there is no known cure for psoriasis, treatments are available that can reduce or eliminate patient symptoms, including biologics, conventional systemic medications, topicals, phototherapy, and oral treatments. Biologics, for example, have changed the therapeutic management of psoriasis, providing clinicians with the opportunity to directly target known mediators in pathogenesis of the disease. In addition to the 7 FDA-approved biologic drugs for psoriasis, many novel biologic therapies are currently in the pipeline, ranging from developmental stages to clinical trials. One class of drugs is interleukin-17 receptor blockers and includes ixekizumab, which has completed phase 3 trials.

Along with the emotional and physical impact of the disease on patients and the efficacy and tolerability of treatment, clinicians need to consider cost when choosing a psoriasis therapy. First Report Managed Care conducted a review of health economic and outcomes research data and identified 3 studies that evaluated cost. One study examined the economic burden of psoriasis in the United States. A second study reviewed the cost efficacy of FDA-approved systemic treatments. The final study compared the cost of 3 biologic agents. This article provides an overview of these studies.

The total cost of psoriasis in the United States is unknown and literature examining the overall costs of disease burden and therapies used to treat psoriasis in the United States is lacking. Therefore, Brezinski et al conducted a comprehensive study to determine the US economic burden of psoriasis from a societal perspective [JAMA Dermatol. 2015;151(6):651-658].

The researchers looked at PubMed and MEDLINE databases for economic analyses published between 2008 and 2013. They focused on 4 categories of cost: direct costs (eg, medical evaluations and treatment); indirect costs, which measure how psoriasis affects work productivity; intangible costs, analyzing the impact of psoriasis on quality of life; and medical expenses related to psoriasis comorbidities. The base year costs were adjusted to 2013 US dollars using the Consumer Price Index for All Urban Consumers and multiplied by the estimated number of patients with psoriasis in 2013. Among the 100 articles identified, 22 studies met the inclusion criteria and were included in the systematic review.

The direct, indirect, intangible, and comorbidity costs of psoriasis in the United States are summarized in Table 1. The estimated annual expenses of managing psoriasis in the United States totaled between $112 billion and $135 billion in 2013. Of all 4 cost sources analyzed, the researchers found that the economic burden is driven largely by direct costs, which were estimated to exceed $8000 annually per person. This was followed by coping with cost of medical comorbidities, which reached almost $5000 annually. Indirect costs, which take into account work absenteeism or lost productivity on the job due to psoriasis, were estimated at more than $4000 per person annually—or as much as $35.4 billion for the total US annual cost. The researchers noted that intangible costs were hard to measure. A willingness-to-pay model is 1 method to determine these costs. One study found that individual patients with psoriasis were willing to pay $1114 annually for symptom relief or $2.3 billion per year for all patients, after adjusting for severity.

“Defining the economic burden of psoriasis from a societal perspective is the foundation for innovating and providing access to cost-effective therapies that will result in improved patient

outcomes,” concluded the investigators. Cost Efficacy of Psoriasis Treatments Newer psoriasis treatments tout higher efficacy but are generally more expensive, according to findings by

D’Souza et al published in the [J Am Acad Dermatol. 2015;72(4):589-598].

To estimate the cost efficacy of FDA approved systemic psoriasis treatments, the researchers conducted a literature review and identified 26 studies encompassing 39 treatment regimens (N=7099 patients) that met the study criteria. The FDA-approved psoriasis treatments included narrowband ultraviolet B light phototherapy (NBUVB), psoralen plus ultraviolet A light phototherapy (PUVA), acitretin, methotrexate, cyclosporine, etanercept, adalimumab, infliximab, and ustekinumab. The researchers standardized total expenses by calculating per month of treatment considering the number needed to treat (NNT) to achieve a 75% reduction in the Psoriasis Area and Severity Index (PASI 75) score. The findings showed that methotrexate ($794.05- $1502.51) and cyclosporine ($1410.14 for 3 mg/kg/ day-$1843.55 for 5 mg/kg/day) had the lowest monthly costs per NNT to achieve PASI 75. The biologic agents infliximab ($8704.68-$15,235.52) and ustekinumab 90 mg ($12,505.26-$14,256.75) were the most expensive therapies. To achieve PASI 75, the monthly costs per NNT for other therapies were:

• NBUVB ($2924.73)

• Adalimumab ($3974.61-$7678.78)

• Acitretin ($4137.71-$14,148.53)

• Ustekinumab 45 mg ($7177.80-$7263.99)

• PUVA ($7499.46-$8834.98)

• Etanercept ($8284.71-$10,674.89)

The investigators acknowledged study limitations stating that they opted not to consider a number of contributing factors for simplicity, to account for practice variability, or because inadequate studies are available for evaluation. These included drug rebates and incentives, potential adverse events, comorbidity risk reduction, ambassador programs, and combination therapies.

The researchers noted that the study is “not meant to dictate treatments based solely on costs; rather, our analysis should help both clinicians and patients in choosing between potential treatments by providing meaningful cost efficacy data that can be considered as part of the many factors that ultimately lead to treatment selection.”

Biologic Costs for Psoriasis Rising

Biologics for psoriasis have shown significant reductions in the number of hospital stays, use of other systemic therapies, improved PASI outcomes, and increased patient satisfaction. Yet, the annual cost of these drugs is substantial. In a new study, Cheng et al sought to estimate the annual cost of psoriasis treatment using 3 biologic therapies and assessed the trend over the past decade [Drugs Context. 2014;3:212-266].

Researchers examined the cost of annual treatment paradigms for etanercept, adalimumab, and ustekinumab using the average wholesale price. Trends were assessed by calculating the percentage change in annual cost compared with the previous year. A sales-based cost of drugs was estimated using gross US sales of each drug and estimate of the total number of patients treated based on prescription data.

The cost analysis demonstrated that the annual cost of biologic drugs is expensive and continues to rise each year. The estimated annual cost of the 3 biologic agents ranged from $36,038 to $44,924. The costs were higher during the first year when loading doses are required. Table 2 provides a breakdown of the annual costs. Furthermore, all 3 drugs increased from 2004 to 2014. The percentage change in cost for etanercept from 2004 to 2014 was 120%, for adalimumab from 2004 to 2014 was 103%, and for ustekinumab from 2010 to 2014 was $53%. For the 5-year interval 2010 to 2014, the change in cost for etanercept was 48% and for adalimumab was 64%. The sales-based cost of drugs was highest for ustekinumab ($25,012), then adalimumab ($6786), and etanercept ($6629). Sales-based cost increased an average of 20% per year, reported the investigators.

The researchers cited several study limitations. The analysis did not include specific direct costs such as physician visits, laboratory tests, and treatment for adverse events. While indirect costs (eg, comorbidities and increased mortality with severe psoriasis) are also important considerations, the researchers were unable to measure these costs and they were not included in this therapeutic-specific analysis. Furthermore, in their estimate of the sales-based cost according to the total number of patients treated with biologic drugs, the researchers assumed that patients filled 2 prescriptions each year, but this estimate may not reflect true prescribing patterns. Also, the sales-based cost did not reflect the specific contracts and prices of the insurers of individual patients.

“As a significantly low cost, highly effective, safe alternative to biologics for patients who have failed conventional therapy is not on the horizon, costs will continue to play a part in the choice of therapy for severe psoriasis,” said the researchers.—Eileen Koutnik-Fotopoulos