The effectiveness and safety of biosimilars for psoriasis appear to be similar to the originator biologics, reported the authors of a review of studies comparing the two.
“This systematic review found that there was no clinically or statistically significant difference in the efficacy and safety between biosimilars and originators of adalimumab, etanercept, infliximab, and ustekinumab for the treatment of psoriasis,” senior study author and clinical lecturer Zenas Z. N. Yiu, MBChB, PhD, and his colleagues at the University of Manchester, England, wrote in JAMA Dermatology.“The biosimilars evaluated in this study could be considered alongside originators for biologic-naive patients to improve the accessibility of biological treatments,” they added. “Switching patients currently on originators to biosimilars could be considered where clinically appropriate to reduce treatment costs.”
Biologics versus biosimilars
In contrast to most chemically synthesized drugs, biologics are created from living organisms, and they have complex structures that can vary slightly from batch to batch, Luigi Naldi, MD, director of the department of dermatology of Ospedale San Bortolo, Vicenza, Italy, and Antonio Addis, PharmD, researcher in the department of epidemiology, Regione Lazio, in Rome, wrote in an accompanying editorial.
Once the patent on the “originator” biologic expires, U.S. and European regulators allow other manufacturers to develop similar molecules – biosimilars – through an abbreviated approval process. If the results of a limited number of equivalence or noninferiority clinical trials are acceptable, registration for all the indications of the originator is allowed for its biosimilars. Referring to the expense of biologics, Dr. Naldi and Dr. Addis noted that in the United States, “biologics comprise less than 3% of the volume of drugs on the market, but account for more than one-third of all drug spending.”
Systematic review
Dr. Yiu and his colleagues queried standard medical research databases in August 2022, and included 14 randomized clinical trials (10 adalimumab, 2 etanercept, 1 infliximab, and 1 ustekinumab) and 3 cohort studies (1 adalimumab, 1 etanercept, 1 infliximab and etanercept) in their review.
Twelve trials compared biosimilars vs. originators in originator-naive patients, and 11 trials compared switching from originators to biosimilars vs. continuous treatment with the originator.
The researchers found the following:
At week 16, mean PASI75 (Psoriasis Area and Severity Index) response rates ranges from 60.7% to 90.6% for adalimumab biosimilars, vs. 61.5% to 91.7% for the originator. Mean PASI75 responses for the two etanercept biosimilars were 56.1% and 76.7% vs. 55.5% and 73.4% for the originator. In the ustekinumab study, mean PASI75 responses were 86.1% for the biosimilar vs. 84.0% for the originator.
At week 52, mean PASI75 responses were between 86.3% and 92.8% for adalimumab biosimilars vs. 84.9% and 93.9% for the originator. In the one comparison of an etanercept biosimilar, mean PAS175 responses were 80.9% for the biosimilar vs. 82.9% for the originator.
In studies involving patients switching from the originator to a biosimilar vs. continuing treatment with the originator, 32-week response rates ranged from 87.0% to 91.3% for adalimumab biosimilars and from 88.2% to 93.2% for the originator. In the one ustekinumab study, the 32-week mean PASI75 response was 92.6% after switching from the originator to a biosimilar vs. 92.9% with continuous treatment with the originator.
At week 52, mean PASI75 responses to adalimumab were between 84.2% and 94.8% for patients who switched to biosimilars and between 88.1% and 93.9% for those who stayed on the originator.
At week 52, in all the randomized trials, the incidence of adverse events and serious adverse events among those who switched to the biosimilar and those who continued with the originator were similar. Two cohort studies showed similar safety outcomes between originators and biosimilars, but one reported more adverse events in patients who switched to adalimumab biosimilars (P = .04).
Three clinical trials showed low risk for bias, 11 had moderate risk, and all cohort studies had moderate to high risk for bias.