Infliximab biosimilar posts mostly reassuring data in study.
WASHINGTON -- Data from the first randomized trial of switching from an originator biologic to a biosimilar of the originator indicate that the infliximab biosimilar Remsima is no different from the infliximab originator Remicade in the rate of disease worsening over 1 year across a combination of all its approved indications.
The outcomes of the Norwegian, double-blind, noninferiority trial, called NOR-SWITCH, indicate similar rates of disease worsening across patients switched to Remsima and those who stayed on Remicade. However, exploratory group analyses conducted on the different disease subgroups in the trial (psoriasis, psoriatic arthritis, Crohn's disease, ulcerative colitis, spondyloarthritis, and rheumatoid arthritis) showed a potentially concerning level of disease worsening among Crohn's disease patients on Remsima with a confidence interval that nearly fell entirely within the range favoring Remicade.
In the United States, Remsima, also known as CT-P13, is marketed by Pfizer as Inflectra.
"The NOR-SWITCH study helps to build confidence in biosimilars as a concept," lead author Guro L. Goll, MD, a rheumatologist at Diakonhjemmet Hospital in Oslo, said in an interview at the annual meeting of the American College of Rheumatology where the study results were presented. "And I do think that our study supports that you can safely switch your Remicade patients to biosimilar CT-P13 even though we have not answered all questions, such as the multiple switching issue."
The trial randomized 482 patients who were on stable treatment with Remicade for at least 6 months for any of the six indications for which Remicade and Remsima are approved to either stay on Remicade or switch to Remsima with the same dosing regimen for 52 weeks. Overall, patients had a mean age of about 48 years and 36%-41% were female. They had a mean disease duration of about 17 years and had been taking Remicade for a mean of nearly 7 years.
The primary endpoint was disease worsening during follow-up, according to worsening in disease-specific composite measures and / or a consensus between an investigator and a patient that led to a major change in treatment. The investigators made an assumption of 30% disease worsening across all the indications for the trial's power calculation, based on available literature and observational data.
Disease worsening occurred in 26.2% of patients who stayed on Remicade and 29.6% of patients who switched to Remsima, based on a per-protocol analysis of 202 Remicade and 206 Remsima patients. The 95% confidence interval of the adjusted treatment difference of -4.4% was -12.7% to 3.9%, which was within the pre-specified noninferiority margin of 15%.
Exploratory subgroup analyses of the different disease subgroups showed no statistically significant differences between the two treatments in disease worsening. However, in Crohn's disease patients, who formed the largest subgroup in the study at (155 patients), the adjusted treatment difference was -14.3% (21.2% with disease worsening for Remicade and 36.5% for Remsima) with a 95% confidence interval of -29.3% to 0.7%.
It's difficult to discern whether the 95% CI seen in the Crohn's disease subgroup is a part of the natural variation one would expect to see in a subgroup analysis of different diseases--or if there might be a true signal for disease worsening in the Crohn's disease patients who took Remsima. "The problem is that it's in the largest subgroup that has no other data. If this had been in rheumatoid arthritis, that would be different," coauthor Inge C. Olsen, PhD, a biostatistician at Diakonhjemmet Hospital, said in an interview. Currently, there are no plans to follow up on these results in another study, he commented.
Other issues that the NORSWITCH study does not answer are the outcomes of switching back and forth between Remicade and Rem sima, switching from one infliximab biosimilar to another infliximab biosimilar, and switching from other originator biologies to their biosimilars. "Is that feasible? Is that safe? Will it retain efficacy? We don't know. There's a real need for those studies to be done," Dr. Goll said. The cost of Remsima in Norway was about 75% less than Remicade in 2015 and about 60% less in 2016, she noted.
NOR-SWITCH was funded by the Norwegian government. Some of the investigators disclosed relationships with Pfizer and / or Celltrion, which separately market CT-P13 in different parts of the world.
Caption: Inge C. Olsen (left) and Dr. Guro L. Goll
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|Date:||Feb 1, 2017|
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