{
  "abstract": "Introduction Loss of response to tumour necrosis factor inhibitors (anti-TNF) are often caused by formation of antibodies. Modifiable strategies to suppress antibodies and regain clinical response include anti-TNF dose optimisation and/or addition of immunomodulators (IM). This study aimed to identify the incidence of antibody formation in anti-TNF therapy and whether modifiable strategies were successful in salvaging the drug.Methods All patients with Inflammatory Bowel Disease (IBD) at a large district general hospital who have ever received anti-TNF treatment (infliximab or adalimumab) were identified through the local IBD database. Baseline demographics, disease specific and process-based variables were identified. Chi 2 tests were utilised with a p-value <0.05 considered statistically significant.Results 403 patients were included, of whom 175 (43%) had ulcerative colitis, 223 (55%) had Crohn’s disease. A total of 339 (84%) received infliximab and 64 (16%) adalimumab, of which 187 (55%) and 33 (52%) received IM, respectively. Antibodies were identified in 70 (17%) patients, which was more common in patients taking adalimumab (n=19, 30%) compared to infliximab (n=51, 15%) (p=0.005). Antibody rates in infliximab patients were similar using IM (27 (18%)) versus without IM (24 (13%)), p=0.207. In patients using adalimumab, 6 (18%) had antibodies when using IM compared to 13 (42%) without IM (p=0.038). In patients with antibodies to infliximab in the presence of IM, there was no difference between patients on full dose IM (n=16, 13.2%) compared to low dose IM (n=8, 12.5%).The median time to antibody development was 149 days (IQR 93-460). Patients were more likely to develop antibodies between 113-568 days after starting anti-TNF (n=37, 26%), p=0.001.In the presence of antibodies to infliximab, 25 (49%) patients immediately changed to an alternative treatment. 18 (35%) patients had their dose adjusted. 14/18 patients had repeat levels taken. 9/14 (64%) still had undetectable trough levels with antibodies which resulted in all of them changing biologic. 5/14 (36%) showed improved trough levels and antibody resolution.In the presence of antibodies to adalimumab, 10 (53%) immediately changed to an alternative treatment, 6 (32%) had dose escalated to weekly and 2 (11%) initiated IM. Following repeat levels, 4 (50%) still had antibody presence and the drug was changed.Conclusions This study highlights that antibody formation is prevalent in both infliximab and adalimumab, which developed between 4 and 19 months from anti-TNF use and can be reduced with the use of IMs. However, once there is antibody development, modifiable strategies are unlikely to regain drug response.",
  "authors": [
    {
      "affiliations": [
        "The Royal Wolverhampton NHS Trust, Wolverhampton, United Kingdom"
      ],
      "name": "Sara Sulaivany"
    },
    {
      "affiliations": [
        "The Royal Wolverhampton NHS Trust, Wolverhampton, United Kingdom"
      ],
      "name": "Kanchi Goragandhi"
    },
    {
      "affiliations": [
        "The Royal Wolverhampton NHS Trust, Wolverhampton, United Kingdom"
      ],
      "name": "Maria Ahmad"
    },
    {
      "affiliations": [
        "The Royal Wolverhampton NHS Trust, Wolverhampton, United Kingdom"
      ],
      "name": "Jorann De Araujo"
    },
    {
      "affiliations": [
        "The Royal Wolverhampton NHS Trust, Wolverhampton, United Kingdom"
      ],
      "name": "Rayna Koshy"
    },
    {
      "affiliations": [
        "The Royal Wolverhampton NHS Trust, Wolverhampton, United Kingdom"
      ],
      "name": "Muhammad Umair Khan"
    },
    {
      "affiliations": [
        "The Royal Wolverhampton NHS Trust, Wolverhampton, United Kingdom"
      ],
      "name": "Philip Harvey"
    },
    {
      "affiliations": [
        "The Royal Wolverhampton NHS Trust, Wolverhampton, United Kingdom"
      ],
      "name": "Aditi Kumar"
    }
  ],
  "title": "P249 Exploring outcomes of antibody formation and the influence of immunomodulators in IBD patients on anti-TNF therapy",
  "uid": "56a05a6c-46e7-5aaa-8da4-4a16b87bd429"
}