P602 Clinical/biochemical predictors of response to anti-TNFa therapies in a tertiary referral centre
Tighe D.*1,2, Breslin N.1, Ryan B.1, McNamara D.3
1AMNCH Tallaght/School of Medicine, Trinity College Dublin, Gastroenterology, Dublin, Ireland 2AMNCH Tallaght/School of Medicine TCD, TAGG, Dublin, Ireland 3AMNCH Tallaght/School of Medicine, TCD, TAGG, Dublin, Ireland
Anti-tissue necrosis factor-alpha (TNFα) therapies have resulted in improved outcomes for patients with inflammatory bowel disease (IBD) reducing complications, hospitalisation rates, and need for surgery. However loss of response (LOR), both primary and secondary is a concern and long-term predictive factors are not well understood.
The aim of this study was to assess response rates to anti-TNFα therapy, and to identify any predictors associated with loss of response.
A retrospective, observational study was designed at our centre. Inclusion criteria were all patients older than 17 years old with IBD who started treatment with anti-TNF drugs, either infliximab or adalimumab, between January 2014 to 2016. Treatment failure was defined as the need for dose intensification because of loss of response, surgery, or therapy removal for ineffectiveness/LOR. Patient data and demographics were obtained from patients electronic patient records. Results are shown as OR and 95% CI and analysed using the Chi-square test and multivariable logistic regression analysis.
During the observational period, 99 patients commenced adalimumab therapy, 61 were on maintenance inflixmab therapy. In terms of patient characteristics, for the cohort mean age was 40.5 years, female gender 89 (55.6%), smoking status at anti-TNFα induction 24 (15%). For adalimumab 80 (80.8%) had CD, 43 (70.5%) for infliximab. Mean duration of disease, was 8.09 years, for adalimumab, 11.43 years for infliximab. Response rates were greater overall for patients treated with infliximab versus adalimumab (65.6% v 52.5%, p value 0.05). There was no statistical differences in response rates, in terms of patient characteristics, disease behaviour, location, disease duration. Prior anti-TNFα exposure, was a risk factor for lack of response, 11/21 (52.4%) of infliximab non-responders versus 11/40 (27.5%) for responders, p=0.0327 (95% CI −0.52 to −0.02). Similarly for adalimumab b 4/37 (10.8%) of non-responders had prior anti-TNFα exposure versus 0/43 (0%) for responders, p value = 0.0219 (95% CI −0.20 to −0.0). Mean CRP at week 14 was a good predictor of loss of response. For adalimumab non-responders, 21 (56.7%) had CRP >5, versus 5 (11.6%), p<0.0001 for responders, and a similar, though not statistically significant trend for infliximab, 35.7% versus 22%, p=0.19
Suboptimal or loss of response remains a concern for anti-TNFα therapy. Predictors of loss of response, like week 14 CRP and prior anti-TNFα exposure are useful to identify patients at risk of treatment failure, and to help develop strategies to overcome this.