Cost Savings and Efficacy of Biosimilars in Psoriasis Treatment for Veterans

Biosimilars are an overall safe, effective, and well-tolerated treatment method for patient with psoriasis while also offering substantial cost savings within Veterans Health Administration (VA) plans, according to a review published in the Journal of Dermatological Treatment.¹

The review sought to synthesize current knowledge about the development and efficacy or biosimilars used to treat psoriasis while also evaluating cost savings and how biosimilars have impacted accessibility to biologics.

Psoriasis is a chronic inflammatory condition affecting about 125 million people worldwide, commonly presenting as itchy, scaly plaques on the skin. There are several subtypes, and up to 30% of patients may develop psoriatic arthritis, worsening their quality of life. Despite their effectiveness, biologics are expensive, limiting accessibility, and many patients face hurdles such as trial-and-error with non-biologic treatments and insurance barriers. Biosimilars offer a more cost-effective alternative, with the VA saving over $67 million in 2023 by using 6 biosimilars across all indications.

In the US, there are 20 biosimilars across 4 molecules approved to treat psoriasis, including 10 adalimumab, 4 ustekinumab, 4 infliximab, and 2 etanercept.² However, only 13 (adalimumab, n = 10; infliximab, n = 3; ustekinumab and etanercept, n = 0) have launched on the market, with all the adalimumab biosimilars having launched in 2023.

The review included studies from PubMed, Wright State University Libraries, and Google Scholar, using keywords like "biosimilars for psoriasis," "switching studies," and "cost savings."

Drug survival, the time from initiation to discontinuation of therapy, is crucial for analyzing biosimilars. A drug that is continued is assumed to be effective, tolerated, and safe. One retrospective study showed 81.5% drug survival for adalimumab biosimilars at 1 year, similar to the originator. Another study found anti-tumor necrosis factor (TNF) biosimilars maintained psoriasis severity (PASI ≤ 2) over 48 months. Patients using adalimumab biosimilars as their first treatment showed longer drug survival than those who switched after failing conventional treatments.

Switch type also impacts survival. Infliximab biosimilar users who switched for nonmedical reasons had a 74% survival rate after 1 year, while those switching for medical reasons had only 24%. Multiple switches between originators and biosimilars did not increase immunogenicity, with comparable safety and efficacy observed.

As biosimilars are not identical to originators, safety concerns are paramount for both patients and providers, necessitating thorough monitoring of adverse drug reactions (ADRs). A study involving 113 patients with psoriasis (n = 40 de novo and 73 switching) found no discontinuations due to safety issues. A 48-month study on anti–TNF-α biosimilars reported ADRs like infections and injection reactions in 28% of patients, but no severe effects.

Monitoring is critical, as seen with the infliximab biosimilar CT-P13, where common ADRs included infusion reactions and mild pneumonia, though no major safety signals have emerged. No tuberculosis reactivation was observed with adalimumab and infliximab biosimilars in patients with proper chemoprophylaxis. Infusion reactions were more likely in patients with severe disease but were manageable. The Biologics and Biosimilars Collective Intelligence Consortium regularly monitors the safety and effectiveness of biosimilars, gathering data on serious infections and other ADRs in ongoing surveillance efforts.

Despite growing evidence for biosimilars, many providers remain concerned, especially about patients with psoriasis. A survey showed that 63% of US physicians feel they lack sufficient information on biosimilars, and only 44% are confident in their safety. Providers also worry about losing the choice between originators and biosimilars, with 75% believing forced switching disrupts the provider-patient relationship.

Concerns included interchangeability, where biosimilars can be substituted without provider consent. Patients share worries about treatment efficacy and side effects, though many are open to biosimilars if reassured they can switch back to originators if needed. While switching studies show that biosimilars maintain efficacy and safety, ongoing surveillance is crucial to building provider confidence.

Studies showed higher rates of treatment discontinuation when patients switched from originators to biosimilars. A VA study found that patients were 2.88 to 3.38 times more likely to stop therapy after switching to a biosimilar, possibly due to the nocebo effect—where negative patient expectations led to perceived side effects or worsened efficacy. Psychological interventions aimed at boosting confidence in biosimilars had limited success, suggesting that further research was needed to improve patient trust and compliance.

Research indicated that evaluating the cost-effectiveness of biosimilars is essential for improving access to biologic therapies for chronic diseases like psoriasis, where even small cost differences can be significant. Cost savings from biosimilars depend heavily on confidential discount rates. For example, one European study showed that an adalimumab biosimilar as a first-line therapy saved approximately $3,219 compared to the originator. In Italy, the biosimilar Idacio was found to be cost-effective compared with methotrexate.

A partnership with the VA revealed that, as of October 2023, the agency primarily used the infliximab biosimilar Renflexis for psoriasis patients, requiring discounts over 50% for further biosimilar adoption. In 2023, the VA achieved a cost avoidance of $28,583,032 through biosimilars, contributing to the total $67 million saved. This cost avoidance allows better allocation of pharmacy budgets, potentially increasing access to treatments for all patients within the VA health care system.

References

1. Reese R, Nanavath SR, Martin J, Travers JB, Rohan CA. A review of biosimilars in psoriasis: impacts on efficacy, safety, access, and a first-hand look at biosimilar cost savings within the Department of Veterans Affairs. J Dermatolog Treat. 2024;35(1):2402912. doi:10.1080/09546634.2024.2402912

2. Biosimilar approvals. The Center for Biosimilars^®. Updated October 16, 2024. Accessed October 16, 2024. https://www.centerforbiosimilars.com/biosimilar-approvals