SAN DIEGO – Biosimilar infliximab (Inflectra) was as safe and effective as the original version (Remicade) in an Italian observational cohort study of 547 inflammatory bowel disease (IBD) patients, the largest to date for the biosimilar.
“We can save money with similar efficacy and safety,” said Dr. Gionata Fiorino, a gastroenterologist at the Humanitas Institute in Milan. The findings should reassure physicians in the United States following recent Food and Drug Administration approval of Inflectra.
In the Italian study, 311 patients were new to anti–tumor necrosis factor (TNF) blockers, 139 were previously exposed to anti-TNF therapy, and 97 were switched directly from Remicade.
Dr. Gionata Fiorino
A total of 64 patients had adverse events, 38 (59%) of which were infusion reactions. Infusion reactions occurred in 9 new patients (3%), 7 switched patents (7%), and 21 patients (15%) starting the biosimilar after an anti-TNF drug holiday. Infusion reactions were most likely in patients starting biosimilar infliximab after a break from Remicade; 29% of those patients had infusion reactions, versus 11% exposed to other anti-TNFs.
“When you look at the historical literature, infusion reactions were also reported mainly after a drug holiday” from Remicade, Dr. Fiorino said at the annual Digestive Disease Week meeting.
There were no statistically significant between-group differences in other adverse events, which were mostly dermatitis. Adverse events led to discontinuation in six new patients (2%), two switched patients (2%), and seven drug-holiday patients (5%); again, the differences were not statistically significant.
The study is ongoing, with a median follow-up so far of just 4.5 months. Because of that, the investigators estimated efficacy using a time-to-treat analysis for censored observations. They calculated that more than 90% of patients in all three arms would have a clinical remission at 12 weeks, and about 90% at 24 weeks.
At least for now, the data “do not show any significant issues in terms of safety. Infusion reaction rates in patients previously exposed to anti-TNFs are in line with the literature, especially for those exposed previously to the originator infliximab. The efficacy profile [also] seems to be in line with the originator,” said Dr. Fiorino, who noted that his hospital has saved about $200,000 using biosimilar infliximab over the past year.
There were no patients who remained on Remicade to compare with those who switched; that was the major limitation of the study, and it was because of payers forcing the switch in Italy. Even so, “the infusion reaction rates in those previously exposed to infliximab is lower than in some previous reports” of Remicade, he said.
Dr. John Kaimakliotis
“In America, doctors are not ready to use” biosimilar infliximab because there are no good head-to-head trials against Remicade, and it’s unclear if there ever will be. But meanwhile, “we use it all over Europe. It’s just as good, and about 30%-50% cheaper than Remicade,” Dr. John Kaimakliotis, a gastroenterologist in Cyprus, said after the presentation. “I’ve been using it in my practice for the last 3 years and checking antibodies. There’s basically no difference; it’s just a lot cheaper.”
About 57% of the patients in the Italian study had Crohn’s disease, and the rest had ulcerative colitis. About 42% of the patients were women. Subjects were an average of 32 years old at diagnosis and had a mean disease duration of about 8 years. The study will continue through 2016; serum is being collected for antibody analysis.
There was no industry funding for the work. Dr. Kaimakliotis has no disclosures. Dr. Fiorino is a consultant for numerous companies, including Janssen, a Remicade marketer.