In a recent study conducted by María Paz Martínez-Vidal, MD, PhD, and colleagues from Hospital Universitario San Juan de Alicante in Alicante, Spain, Spanish patients with inflammatory arthritis were found to have higher treatment retention rates when using biosimilar biologics compared to the originator products. The study focused on patients who were prescribed either etanercept or adalimumab and followed them over a period of 2 to 3 years. The results showed a significantly lower discontinuation rate of 33.4% for biosimilars compared to 53.3% for originator products.
Despite the clear advantage of biosimilars in terms of treatment retention, the study did not provide a definitive explanation for why patients preferred biosimilars over the originator products. The two most common medical reasons for discontinuation – adverse effects and lack of efficacy – were not significantly different between the two types of drugs. This lack of clarity highlights the need for further research to understand the patient and clinician preferences when choosing between biosimilars and originators.
The study drew its findings from the Spanish registry called BIOBADASER, which tracks patients with rheumatic diseases prescribed biologic or targeted synthetic drugs. The analysis included 4,162 patients who were prescribed either subcutaneous etanercept or adalimumab between 2016 and 2023. The patients had a variety of inflammatory arthritis diagnoses, with rheumatoid arthritis being the most common among them. The average patient age was around 50, with the majority being women.
In addition to using biosimilar biologics, the study identified other factors that predicted longer treatment retention. Patients with longer disease duration and those taking concomitant methotrexate had a higher likelihood of continuing their treatment. On the other hand, patients who were using the biologics as second- or later-line treatments were at a higher risk of discontinuation. Achieving remission was also mentioned as a reason for discontinuing the biologic, albeit being rare in occurrence.
One interesting observation from the study was the higher rate of nonmedical discontinuations for originator products compared to biosimilars. Reasons for nonmedical discontinuations included supply shortage and hospitals’ strategic decisions. However, there was no significant difference between biosimilars and originators in terms of other reasons for discontinuation, such as pregnancy or loss to follow-up.
The study findings suggest that Spanish patients with inflammatory arthritis have better treatment retention rates when using biosimilar biologics compared to originator products. Despite the lack of clear reasons for this preference, the study underscores the importance of considering biosimilars as a viable option for treatment. Further research is needed to explore the patient and clinician perspectives that influence treatment decisions in clinical practice.
The study sheds light on the benefits of biosimilar biologics in improving treatment retention rates for patients with inflammatory arthritis. By understanding the factors that contribute to treatment continuation, healthcare providers can make informed decisions when choosing between biosimilars and originator products.