Q&A: Biologics Versus Targeted Therapies in Psoriatic Arthritis

In psoriatic arthritis (PsA), tumor necrosis factor-alpha (TNF-α) inhibitors may be more effective than interleukin (IL) 12–23 antagonists among biologic-naïve patients, and more effective than Phosphodiesterase-4 (PDE4) inhibitors among biologic-experienced patients, according to a study published in RMD Open.¹

In this Q&A, corresponding author Jeffrey Curtis, MD, professor of medicine in the Division of Clinical Immunology and Rheumatology at University of Alabama at Birmingham, highlights the study findings.

In the retrospective study, researchers used health plan claims data to compare the effectiveness of IL-12/23 antagonist (ustekinumab), IL-17A antagonists (secukinumab and ixekizumab), PDE4 inhibitor (apremilast), and TNF-α inhibitors (infliximab, etanercept, adalimumab, certolizumab pegol and golimumab) for PsA.

Of the 2730 individuals with PsA, 327 received an IL-12/23 antagonist, 138 received IL-17A antagonists, 624 received a PDE4 inhibitor and 1641 received TNF-α inhibitors. Effectiveness criteria were fulfilled among 19.3%, 29.0%, 25.6% and 32.3% of recipients, respectively.

Among biologic-naïve participants, the IL-12/23 antagonist was less effective than TNF-α inhibitors with fully adjusted relative risk (aRR) compared with TNF-α inhibitors of 0.63 (95% CI 0.45 to 0.89). Among biologic-experienced participants, PDE4 inhibitors were less effective than TNF-α inhibitors (aRR 0.67, 95% CI 0.46 to 0.96).

Rheumatology Network: Why was the study conducted?

Jeffrey Curtis, MD: To be able to provide direct evidence on the effectiveness between the various therapies for psoriatic arthritis.

RN: Were you surprised by the findings?

JC: We were pleased that the methods we used to evaluate differences between PsA treatments yielded results that were more or less consistent with expectations. The reason that this was important is that health plan claims data are rarely used to judge effectiveness (or efficacy) of arthritis treatments.

We previously published a validation study in rheumatoid arthritis that found that health plan claims data is a reasonable proxy for clinical outcome data that is mostly available only in traditional registry, or electronic health record (EHR) data. We adapted that same approach for PsA to be able to evaluate effectiveness of PsA drugs, yet without clinical measures that are rarely available in real-world data sources.

RN: How significant are the results?

JC: They show that PDE4 and IL12/23 medications appear less effective than TNF therapy for PsA. The effect size is likely of a magnitude that is clinically relevant.

RN: What is the current practice and how could the findings possibly change things?

JC: From a methodologic perspective, this provides evidence that health plan claims data might be used to judge the real-world effectiveness of PsA treatments even absent the clinical measures of PsA that are rarely available in most US data sources.

RN: What are the takeaway points for clinicians who may be reading this article?

JC: We have very few head to head real-world studies comparing different biologics and targeted therapies for people with inflammatory arthritis such as PsA. Our results suggest that there are likely to be certain treatments that will confer preferential response in PsA, including TNF inhibitors and IL-17 medications, compared to other options.

In addition, as illustrated by our approach, medical and pharmacy claims data might be used by physician groups (and health plans) to craft a value-based reimbursement program in PsA.

Reference:

Zhang H, Wen J, Alexander GC, Curtis JR. Comparative effectiveness of biologics and targeted therapies for psoriatic arthritis. RMD Open. 2021;7(1):e001399. doi:10.1136/rmdopen-2020-001399