Studies Highlight Real-World Data on GP2015 and Predict Substantial US Cost Savings With Biosimilar Use

Among the first biosimilars to gain US approval was Sandoz’s etanercept biosimilar, GP2015, or Erelzi. The product was authorized by the FDA in 2016, but it has not yet launched in the US market due to long-running patent disputes related to Amgen’s innovator product, Enbrel.

In other markets, however, the biosimilar is a widely used treatment option, and data presented at the American College of Rheumatology’s 2019 meeting, held this week in Atlanta, Georgia, show that not only is the biosimilar safe and effective in real-world practice in ex-US markets, but it could also bring about substantial savings in the United States once it becomes available.

First, researchers reported on an interim analysis of the COMPACT study, a multicenter, prospective, observational cohort study that evaluates drug persistence, effectiveness, safety, and quality of life with use of the biosimilar in patients with rheumatic diseases.¹ The study includes 430 patients in Germany, the United Kingdom, Spain, Poland, and Canada who are being treated for rheumatoid arthritis (RA), ankylosing spondylitis (AS), and psoriatic arthritis.

In total, 37.7% of patients in COMPACT switched from the reference etanercept, 7.4% switched from other anti—tumor necrosis factor therapies, 46.3% were naïve to biologics, and 8.6% were naïve to disease-modifying treatments. Most (59.5%) patients had RA.

Among the patients with RA, as the largest population, the total mean (SD) disease activity scores in a count of 28 joints with erythrocyte sedimentation rate were 2.9 (1.4) among all 4 groups at baseline, and scores fell to 2.6 (1.3) by week 12. Health assessment questionnaire—disability index scores for the RA group fell from 0.88 at baseline to 0.76 at week 12.

In total, 33% of patients had at least 1 adverse event (AE), and 2.8% of patients discontinued due to AEs.

“The interim analysis from the COMPACT study adds evidence to a growing body of research that confirms the safety and efficacy of biosimilar etanercept,” said investigator Marc Schmalzing, MD, deputy head and senior physician in the Department of Rheumatology and Clinical Immunology, University of Wurzburg, in a statement. “In addition to the existing clinical research on Erelzi, we now can see how this biosimilar is performing in a real-world patient population setting with comorbidities and concomitant medications.”

In addition to the real-world data from Europe, researchers from Sandoz also presented new findings on the financial implications of switching US patients to biosimilar etanercept once it becomes available.

The research team assessed the short-term and long-term impacts of making a formulary change from the reference to the biosimilar for RA, juvenile idiopathic arthritis, and AS over a 5-year time horizon. The number of existing and new patients was calculated on a hypothetical population of 1 million within an integrated delivery network.

A base-case discount price for the biosimilar was estimated using average selling price data from CMS, and for patients switching, biosimilar market share was assumed to be 95% in year 1 and 100% in year 5. Low, medium, and high costs to implement a formulary change were explored, and activities such as nurse time for patient education and pharmacist time to manage requests were included as labor costs.

For the hypothetical population, 1331 patients were assumed to be treated by year 5. In terms of short-term administrative costs, total nonpharmacy costs of implementing a formulary change were $55,518 in the low-cost scenario, $105,518 in the medium-cost scenario, and $205,518 in the high-cost scenario. Total 5-year savings in terms of pharmacy costs were $62.4 million, $62.4 million, and $62.3 million for the 3 scenarios, respectively, or $10,076, $10,067, and $10,049 per patient per year.

“This model shows that substantial pharmacy cost savings, about $10,000 per switched patient per year, far outweighed the relatively minor incremental administrative and labor costs associated with implementation of a formulary change,” said Edward Li, PharmD, MPH, author and associate director of health economics and outcomes research at Sandoz.

With respect to when the US market could finally see the launch of the biosimilar and reap some of those cost savings, Sandoz this week said in a statement that opening briefs have been filed in an ongoing etanercept patent litigation case in the US Court of Appeals, and the company hopes to resolve the case shortly to bring the product to patients “as soon as possible.”

References

1. Schmalzing M, Askari A, Walsh D, et al. Etanercept biosimilar GP 2015 (Erelzi) in rheumatic diseases: interim analysis of real-world data from COMPACT: a multicentric, prospective, observational cohort study. Presented at: The American College of Rheumatology Annual Meeting, November 8-13, 2019; Atlanta, GA. Abstract 553.

2. Mezzio D, Li E, Balu S. Long-term financial impact of switching from reference to biosimilar etanercept when considering short-term formulary management costs in the US. Presented at: The American College of Rheumatology Annual Meeting, November 8-13, 2019; Atlanta, GA. Abstract 251.