LONDON, United Kingdom — For patients with inflammatory arthritis, a switch from infliximab (Remicade) to a biosimilar (Remsima) does not appear to change disease activity status or the propensity to flare, a preliminary analysis of a Danish nationwide registry suggests.
"We need a longer-follow-up, but at 3 months, we can say that, on a group level, preliminary data looked quite reassuring," said Bente Glintborg, MD, PhD, from the Gentofte University Hospital and the DANBIO registry in Copenhagen, Denmark.
"Last year, our authorities made the decision to switch all our patients treated with the original infliximab to the biosimilar for financial reasons," she explained. This applied to all patients, regardless of the disease being treated.
"It was a nonmedical switch, and we did what was expected of us," she told Medscape Medical News. "Of course, there was some anxiety in doing this because there were no observational data at the time and we didn't know what would happen in real life."
The study results were was presented here at the European League Against Rheumatism Congress 2016.
Dr Glintborg and her colleagues assessed 647 patients from the DANBIO registry; about half had rheumatoid arthritis and the other half were receiving treatment for either axial spondylitis or psoriatic arthritis. Approximately half of the cohort was female, and median age was 56 years.
The DANBIO registry is a nationwide registry that encompasses more than 95% of all patients with inflammatory arthritis under medical care in Denmark (Rheumatology Oxford. 2011;50:69-77).
"Patients had been treated for nearly 7 years when they were switched. For most patients, infliximab had been their first biological disease-modifying antirheumatic drug," Dr Glintborg reported.
The researchers examined disease activity measures 3 months prior to the switch, at the switch, and 3 months after the switch.
For patients with rheumatoid arthritis or psoriatic arthritis, the biosimilar dose was 3.3 mg/g administered every 7 weeks; for patients with axial spondylitis, the dose was 4.8 mg/kg administered every 6 weeks.
More than two-thirds of patients with rheumatoid arthritis or psoriatic arthritis were also taking methotrexate during the study period.
"Disease activity was largely unaffected in the majority of patients 3 months after the switch, and was comparable to fluctuations in disease activity observed in the 3 months prior to the switch," Dr Glintborg reported.
Although there were trends toward changes in measures of disease activity, they were not clinically relevant, she explained.
Table. Disease Activity During the Study Period
| Outcome Measure | 3 Months Before Switch | At Switch | 3 Months After Switch |
| Rheumatoid arthritis or psoriatic arthritis | |||
| Disease activity score in 28 joints | 2.3 | 2.3 | 2.3 |
| Health Assessment Questionnaire score | 0.6 | 0.6 | 0.5 |
| C-reactive protein (mg/L) | 4.0 | 4.0 | 6.0 |
| Global visual analog scale score (mm) | 26.0 | 27.0 | 26.0 |
| Axial spondylitis | |||
| Bath Ankylosing Spondylitis Disease Activity Index score | 26.0 | 23.0 | 23.0 |
Flare Rates
Before the switch, about 10% of patients with rheumatoid arthritis experienced a flare; this was unchanged after the switch, Dr Glintborg reported. Flare rates were also unchanged for patients with axial spondylitis.
At a median follow-up of 139 days, 45 patients (7%) had withdrawn from treatment, approximately half because of a lack of therapeutic effect.
"Patients who stopped treatment had been treated for a median of 6 years before they stopped," said Dr Glintborg.
"We think this warrants further investigation, which we can do when we receive the 1-year data," she added.
In many countries, considerable effort is being made to get patients on biosimilars when available. For example, health authorities in the United Kingdom are forcing the use of biosimilars in hospitals.
At least some of the rheumatology consultants aren't particularly happy with this mandate because they have never used them before, Sean Gavan, from the Manchester Centre for Health Economics in the United Kingdom, pointed out during a news conference.
"It's very important that physicians communicate well with their patients and be really positive when they recommend a biosimilar," said Johanna Hazes, MD, from Erasmus Medical Centre Rotterdam in the Netherlands. Otherwise, patients will pick up on their hesitancy and be apprehensive about treatment.
"We know from our study that patients who have positive expectations for their outcomes have better outcomes, and this is true for diseases other than rheumatoid arthritis," Dr Hazes said.
"If physicians are only prescribing these drugs because they have to, then we can be sure that patient outcomes will not be as good."
European League Against Rheumatism (EULAR) Congress 2016. Abstract OP0225. Presented June 10, 2016.
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Cite this: Inflammatory Arthritis Stable After Switch to Biosimilar - Medscape - Jun 13, 2016.
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