A recent study found no statistically significant differences in the effectiveness of adalimumab biosimilars compared with the adalimumab originator biologic for treating psoriasis.
In the study, published in JAMA Dermatology, investigators analyzed data from the British Association of Dermatologists Biologics and Immunomodulators Register (BADBIR) from September 2007 to January 2023. They used a target trial emulation approach to assess the effectiveness of biosimilars in both new users and patients switching from the adalimumab originator.
Among 11,400 included patients (60.7% male, mean age = 45.3 years), the investigators identified 6,133 patients in the new user analysis (5,416 initiating the adalimumab originator, 382 initiating the first adalimumab biosimilar [Amjevita], and 335 initiating the second adalimumab biosimilar [Imraldi]) and 5,267 in the switcher analysis (3,808 continuing the adalimumab originator, 847 switching to the first adalimumab biosimilar, and 612 switching to the second adalimumab biosimilar).
The primary outcome measures were achieving an absolute Psoriasis Area and Severity Index (PASI) score of 2 or less or 4 or less at 12 months following treatment initiation or switching. Among new users, the adjusted odds ratios (OR) for achieving a PASI score of 2 or less were 0.98 (95% confidence interval [CI] = 0.78–1.25) for the first adalimumab biosimilar and 0.83 (95% CI = 0.64–1.07) for the second adalimumab biosimilar compared with the adalimumab originator. For switchers, the adjusted ORs were 1.19 (95% CI = 0.94–1.51) for the first adalimumab biosimilar and 0.92 (95% CI = 0.72–1.18) for the second adalimumab biosimilar compared with continuing the adalimumab originator.
Similar results were found for the PASI score of 4 or less outcome, with no statistically significant differences between biosimilars and the adalimumab originator in either analysis.
"In this study, [the first and second adalimumab biosimilars] were as effective as [the adalimumab originator] for both new starters and patients switching to biosimilars from [the adalimumab originator]," concluded the study authors team led by Duc Binh Phan, MSc, of the Dermatology Centre at the University of Manchester.
Adverse events were recorded in 41.7% of new users of the adalimumab originator, 36.1% of new users of the first adalimumab biosimilar, and 42.6% of new users of the second adalimumab biosimilar. Among continuous users and switchers, adverse event rates were similar across groups.
While biosimilars are known to offer significant cost savings and potentially improve patient access to treatment, concerns about efficacy differences have limited their widespread adoption. This study, leveraging real-world clinical data, supports these biosimilars as viable alternatives to the adalimumab originator.
Limitations of the study included missing outcome data and wide confidence intervals in the switcher analysis, suggesting the need for further research with larger sample sizes. The study's target trial emulation approach helped reduce bias by ensuring detailed baseline covariates were considered.
Conflict of interest disclosures can be found in the study.