Severe adverse reactions are rare with infusions of infliximab in a community setting
- Correspondence to Yusuf Yazici
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In this study, Ducharme and colleagues report on the experience in community infusion centres with patients using infliximab for a variety of indications. As the authors state, randomised clinical trials are not the ideal environment to assess safety,1 2 and ‘real-world’ experience after the drugs are available to use give us a more complete picture for both the efficacy and the safety of any medication. This is a commendable effort that will provide important information for practitioners and patients alike.
In this retrospective chart review study, all infusions over 18 months in selected clinics in Ontario were reviewed. These centres had protocols in place, as they should, for recording the incident and level of an adverse event and also the process of addressing the event.
A total of 3161 patients received 20 976 infusions for various conditions, including rheumatoid arthritis, psoriatic arthritis and Crohn's disease. Most of the patients were already on infliximab, with less than a quarter of the patients with a new start. Mean number of infusions was just over 6, and the mean and the median dose of infliximab used was 5 mg/kg. Overall, 4.2% of all the infusions in 18.9% of patients documented an adverse event. Importantly, close to 40% of these were delayed reactions, defined as happening more than 24 h after the infusions. As would be expected, patients receiving their first infusions had a slightly higher rate of adverse events, compared to those already on the medication. Also some diagnoses were associated with higher incidences of adverse events. Severe reactions were rare with 5.3% of adverse events in 0.1% of infusions and none requiring hospital admission.
Several shortcomings are to be noted. A prospective study would of course be ideal, but, short of that, this is the kind of protocol-driven setting that can give us valuable information. Combining all diagnoses together helps with getting to larger numbers of patients but dilutes the possible differences that may be noted between different conditions. As the authors also suggest, more infusions per patients might have been desirable, but this is a good start. One shortcoming of course is that patients who were already on infliximab and had previously had a reaction towards it were dropped from the study. The cleaner cohort would be all new starts, and this is appropriately addressed by the authors. Data for the new start reaction rates are given, which are comforting, but it is a much smaller number than the whole cohort.
The report has the strength of being the largest study to date, following a detailed protocol regarding classification of adverse events and the response to each category, which makes interpretation of the data much easier and relevant to everyday clinical practice.
The important take-away from this study is that infliximab is a safe drug to infuse in the community setting and this may help more patients who do not have access to a hospital setting get this effective medication. A prospective study in new infliximab starts would be a good next step to determine whether the results of this study hold and it may also be a good idea to follow patients for up to 5 years to make sure more infusions per patients are captured; long term safety data are required for not only infliximab but also for all biologic agents we commonly use.
Competing interests YY has been a consultant or speaker for BMS, Celgene, Centocor, Genentech, Merck, Pfizer, Roche and UCB.