Table 1

Characteristics and results of clinical studies on anti-IL-17 drugs

Reference	Study type	Patients n	Disease	Treatment	Results
39	Phase 2	130	CD	BRO	Worsening CD with BRO. No statistically significant difference in CDAI response between BRO and placebo.
35	Phase 2	59	CD	SEC	31% of early discontinuation. Elevation of inflammatory markers (CRP, FC, CDAI). 14 serious adverse events.
11	Phase 3	226	AS	SEC	No case of CD or UC
12	Phase 3	290	AS	SEC	EIAR for CD: 0.4, for UC 0.5
13	Phase 3	200	AS	SEC	Incidence: 0.8 per 100 PY
14	Phase 3	274	AS	SEC	EAIR for CD: 0.6, for UC: 0.2
15	Phase 3	219	AS	SEC	EIAR for CD : 0.7
17	Phase 3	219	AS	SEC	EIAR for CD: 0.6, for UC: 0.6
19	Review of phase 3 studies	4209	PsO	IXE	Three discontinuations for CD, 5 for UC. Four exacerbations in patients with known CD. 10 exacerbations in patients with known UC.
67	Systematic review and meta-analysis	16 690	PsO PsA AS	IXE SEC BRO	12 new IBD cases (anti-IL-17 group). 0 new IBD cases (placebo group). No increased risk of new IBD onset or diarrhoea under anti-IL-17 vs placebo (p=0.35).
68	Systematic review	8742	PsO	IXE SEC BRO	Association with IBD exacerbation. Caution in case of diagnosed IBD or personal history suggesting IBD.
69	Retrospective evaluation of pooled studies	7355	PsO PsA AS	SEC	EAIRs in PsO: 0.13 for UC, 0.05 for CD and 0.01 for IC. EAIRs in PsA: 0.08 for CD, 0.08 for UC and 0.05 for IC. EAIRs in AS: 0.2 for CD, 0.4 for UC and 0.1 for IC. SEC not associated with increased EAIRs over time.
70	Phase 3	590	AS	SEC	Pooled exposure-adjusted incidence rates from grade 3 and 4 for CD: 0.7/100 PY
71	Phase 3	341	AS	IXE	One case of probable CD in the group with IXE every 2 weeks

AS, ankylosing spondylitis; BRO, brodalumab; CD, Crohn’s disease; CDAI, Crohn’s Disease Activity Index; CRP, C reactive protein; EAIRs, exposure-adjusted incidence rates (per 100 patients years); FC, faecal calprotectin; IBD, inflammatory bowel disease; IC, indeterminate colitis; IL-17, interleukin-17; IXE, ixekizumab; PsA, psoriatic arthritis; PsO, psoriasis; PY, patient years; SEC, secukinumab; UC, ulcerative colitis.