At the moment patients are given standard Infliximab (IFX) dosing, their response monitored and doses adjusted accordingly. Ideally we would like to individually tailor doses to use the lowest dose and keep disease in remission. As has been previously discussed in this blog, around 50% of patients will eventually lose response to biologicals; therefore, maintaining response is crucial. If patients lose response, there is no agreed upon way to adjust dose; some centres would increase the dose or frequency depending on clinical symptoms whilst others would measure drug and antibody levels to guide them.
In adults who have lost to response to Infliximab this study investigates ways to regain response. All patients were on standard IFX regimes and found to have lost response, they were then randomised to either receive increased frequency of dosing or dosing was adjusted based on their antibody and trough levels. The study found similar rates of regaining response in both groups but there was significantly less cost involved for those were dosing was dependent on drug and antibody levels. Based on their results, the authors created an algorithm for dose adjustments in those losing response to IFX based on drug trough and antibody levels. This included when to stop IFX and to consider other treatment options such as surgery or switch to Adalimumab.
This study is interesting and increases our knowledge on the best ways to use anti-TNF drugs. In many centres, drug trough and antibody levels are not available whilst, in other areas, it can be difficult to give patients increased doses with cost often cited as a reason. This study argues that the cost of drug levels are offset by the benefit in money saved through individualised treatment for patients. Although it is disappointing that individualised treatments do not result in more patients continuing to respond to IFX, the improved cost effectiveness and guidance on when to escalate treatment or to switch to a different treatment option are extremely useful.
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