AT EULAR 2017
MADRID – Two biosimilar tumor necrosis factor inhibitor (TNFi) products are no more immunogenic than their reference biologic counterparts in patients with rheumatoid arthritis, according to the results of two studies presented at the European Congress of Rheumatology.
Results of one study, which involved 544 RA patients, showed 33.1% treated with SB5, a biosimilar candidate for adalimumab (Humira), and 32% of those who were treated with reference adalimumab developed antidrug antibodies (ADAbs) after 24 weeks’ treatment.
In the second study, which involved 596 RA patients, significantly fewer treated with SB4, a biosimilar candidate for etanercept (Enbrel) developed ADAbs versus reference etanercept (0.7% vs. 13.1%, P less than .001).
In both studies the development of ADAbs with the biosimilar or reference products was found to attenuate the clinical responses seen, with trends towards lower American College of Rheumatology (ACR) scores with higher levels of ADAbs.
Dr. Jonathan Kay
Dr. Kay observed that for both SB5 and adalimumab, efficacy at week 24 was higher among patients who achieved drug trough levels of 1.274 microg/mL or more than this threshold set for achieving a good EULAR response. At week 24, 32.9% and 43.2% of patients treated with the biosimilar adalimumab and reference adalimumab, respectively, had drug trough levels greater than or equal to the threshold, and achieved a good EULAR response, with 61.7% and 51.8% achieving a moderate EULAR response, and 5.4% and 5% no EULAR response. Dr. Kay also reported that similar percentages of patients treated with the biosimilar and reference adalimumab achieved a low disease activity (LDA) score or were in remission at 24 weeks if the drug trough levels were 1.274 microg/mL or above, at 32.9% and 43.2% for LDA and 20.8% and 25.9% for remission.
Sara Freeman/Frontline Medical News
Dr. Jirí Vencovský
“Efficacy tended to be lower in patients with ADAbs,” Dr. Vencovský, who is vice-director of the Institute of Rheumatology, Charles University in Prague, Czech Republic, said. For both the ACR50 and ACR70 responses at week 24, no differences were seen between the patients who received biosimilar or reference etanercept. The impact on the ACR20 response could not be evaluated in the biosimilar group due to the low incidence of ADAbs, Dr. Vencovský said. The effect of injection site reactions on efficacy was also studied, and while no correlation was found between injection site reactions and the development of ADAbs, efficacy did tend to be slightly lower in some parameters measured in the patients who experienced injection site reactions. Dr. Vencovský reported that fewer patients treated with the biosimilar candidate experienced injection site reactions than those with the reference etanercept (3% vs. 16%).
The study presented by Dr. Kay is currently under consideration for publication and has previously been presented at the American College of Rheumatology.
Samsung Biopics sponsored the studies. The company has several biosimilar products in the pipeline, including SB2, which is a biosimilar for infliximab (Remicade) that was approved for use in the United States in April 2017. Although not yet available in the U.S., the company’s biosimilar adalimumab (SB5) is undergoing regulatory review by the European Medicines Agency (EMA) and it’s biosimilar etanercept is available in Europe as Benpali and Canada as Brenzys.
Dr. Kay has received research support paid to his institution from AbbVie, Genentech, Pfizer, Roche Laboratories, and UCB. He has also acted as a consultant to several companies that develop or market biosimilars including Samsung Bioepis who make the two biosimilar products mentioned in this report. Dr. Vencovský disclosed acting as a consultant to Samsung Bioepis and to Biogen, and acting as a speaker for UCB, Pfizer, AbbVie, MSD, Novartis, and Eli Lilly.