Background and importance Ulcerative colitis (UC) presents high levels of tumour necrosis factor alpha (TNFα) in colonic mucosa. Poor response to retreatment with a second TNF antagonist agent (anti-TNF) has been suggested in patients refractory to first line treatment with an anti-TNF.

Aim and objectives To evaluate long-term effectiveness of adalimumab as second anti-TNF and influence of the first anti-TNF treatment in UC.

Material and methods A descriptive retrospective study was conducted in patients with UC treated with adalimumab as second anti-TNF (January 2013–July 2021). Variables recorded were: age, sex, previous anti-TNF, response to anti-TNF treatment, duration of therapy and Mayo clinic score (MCS). Effectiveness was evaluated by MCS at 6, 36 and 72 months. Clinical remission (R) was defined as MCS ≤2 points. Clinical response (CR) was a decrease of ≥3 points in MCS with respect to baseline. Lack of response (LOR) was defined as none of the above. Patients with LOR and treatment suspension in a certain week were assumed as LOR in subsequent weeks. Influence of effect of first anti-TNF was estimated using association between types of response to first and second anti-TNF. Primary non-response (PNR) to anti-TNF therapy was considered as LOR in induction period (before week 10 for infliximab and before week 4 for adalimumab). Secondary non-response (SNR) to anti-TNF treatment was defined as LOR after induction period.

Results Thirty-one patients were included (54.8% women). Median age was 43 (86–21) years. All patients received infliximab as first anti-TNF. Median adalimumab treatment duration was 18 (1–91) months. MCS at 6 months: 32.26% R, 19.36% CR and 48.38% LOR. MCS at 36 months: 25.80% R, 3.23% CR and 70.97% LOR. MCS at 72 months: 6.45% R, 3.23% CR and 90.32% LOR. Two patients with PNR to adalimumab (2/10, 20%) had PNR to first anti-TNF and 8 with PNR to adalimumab (8/10, 80%) presented SNR to first anti-TNF. All patients with SNR to adalimumab demonstrated SNR to first anti-TNF.

Conclusion and relevance Adalimumab as a second anti-TNF maintained more than a quarter of patients with UC in R at 36 months, but almost all patients lost effectiveness at 72 months. Adalimumab’s PNR was less frequent in patients with PNR to a first anti-TNF therapy than in those with SNR.

Conflict of interest No conflict of interest