Adalimumab Biosimilars Comparable to Originator for Treatment of Psoriasis

New findings suggest the adalimumab originator Humira’s efficacy for psoriasis is comparable to that of Amjevita and Imraldi, a set of biosimilars, for both new starters and individuals shifting to biosimilars from Humira.1

These findings were the result of new research conducted to assess any differences in the efficacy of adalimumab’s biosimilars and its originator among patients who have psoriasis. This research was authored in part by Duc Binh Phan, MSc, from the Dermatology Centre at the University of Manchester Biomedical Research Centre in the United Kingdom.

Phan et al. highlighted the lack of clinical findings on this subject and concerns raised among prescribers as well as patients.2 Such limits could, the investigators noted, potentially limit the widespread implementation of biosimilars in clinical practice.

“In this study, we assessed the effectiveness of adalimumab biosimilars compared with the adalimumab originator, Humira, for the treatment of psoriasis by emulating target pragmatic RCTs using real-world data from the British Association of Dermatologists Biologics and Immunomodulators Register (BADBIR),” Phan and colleagues wrote.1

Analyzing Adalimumab Originator Versus Biosimilars

Using BADBIR, participation from over 160 dermatology centers of varying sizes took place across the UK as well as Ireland, allowing this analysis to be a substantial source for real-world data on biosimilars in psoriasis therapy. In this cohort study, the target trial emulation framework was applied by the investigative team to look into the comparative efficacy of adalimumab biosimilars versus Humira.

The BABDIR prospective pharmacovigilance registry, known to have been established in 2007, provided the team with their data on individuals undergoing treatment with biologic and conventional systemic drugs for psoriasis. The defined 2 hypothetical pragmatic randomized controlled trials (RCTs) for the study.

The first RCT was designed to evaluate the results of initiating adalimumab biosimilars Amjevita or Imraldi, compared to the initiation of Humira in those beginning adalimumab therapy for psoriasis. In the team’s second RCT, they looked at the effectiveness of a switch from Humira to either Amjevita or Imraldi versus continuation with Humira among individuals who had been on the latter medication for over 2 years.

These 2 trials were known as the new user analysis and the switcher analysis, respectively. Observational data were implemented from BADBIR for these analyses, ensuring alignment with the target trials in terms of strategy, criteria for subject eligibility, etc.

Their primary outcomes were determined to be the attainment of a Psoriasis Area and Severity Index (PASI) score of 2 or less and a PASI score of 4 or less at 12 months post-index date. For the purposes of ensuring at least a single year of follow-up for each of the study subjects, the investigative team restricted cohort entry to no later than January 2022, with the study concluding in January 2023.

Inverse propensity treatment weighting was applied by the investigators to account for confounders. They also used multiple imputation methods and inverse probability of censoring weighting. They used logistic regression models to assess outcome differences across trial cohorts.

There were 11,400 individuals included in the RSTs, with 60.7% being male and the mean age of participants being 45.3 years. In the investigators’ new user analysis, 6133 subjects were involved. These included 5416 who began using Humira, 382 with Amjevita, and 335 with Imraldi. In their switcher analysis, 5267 individuals were involved, with 3808 continuing Humira, 612 switching to Imraldi, and 847 switching to Amjevita.1

The likelihood of a PASI score of 2 or less among new users was shown by the investigators to not significantly differ between biosimilars and their originator (Imraldi: aOR, 0.83; 95% CI, 0.64-1.07; Amjevita: adjusted odds ratio [aOR], 0.98; 95% CI, 0.78-1.25).1 In a similar vein, the research team did not identify significant difference in the probability of attaining a PASI score of 4 or less (Imraldi: aOR, 0.91; 95% CI, 0.69-1.20; Amjevita: aOR, 1.07; 95% CI, 0.84-1.37) compared with users of Humira.

Among those who decided to change medications, the team did not observe a statistically significant difference in the attainment of a PASI score of 2 or less (Imraldi: aOR, 0.92; 95% CI, 0.72-1.18; Amjevita: aOR, 1.19; 95% CI, 0.94-1.51).1 They also did not observe such a difference in the attainment of a PASI score of 4 or less (Imraldi: aOR, 1.00; 95% CI, 0.70-1.41; Amjevita: aOR, 1.32; 95% CI, 0.96-1.84) compared with those who remained on the originator.

“We found no differences in the probability of achieving a PASI score of 2 or less or a PASI score of 4 or less at 12 months between the comparators in either analysis,” they concluded. “In this study, Amjevita and Imraldi were as effective as the originator Humira for the treatment of psoriasis.”1

References

1. Phan DB, Bewley AP, Laws P, et al. Effectiveness of Adalimumab Biosimilars and Originator for Psoriasis. JAMA Dermatol. Published online March 05, 2025. doi:10.1001/jamadermatol.2025.0055.

2. Leonard E, Wascovich M, Oskouei S, Gurz P, Carpenter D. Factors affecting health care provider knowledge and acceptance of biosimilar medicines: a systematic review. J Manag Care Spec Pharm. 2019;25(1):102-112. doi:10.18553/jmcp.2019.25.1.102.