Background/Purpose:  IBD is often associated with other CID, such as rheumatoid arthritis (RA), psoriatic arthritis (PsA), ankylosing spondylitis (AS), and psoriasis (PsO). Newer biologic agents such as IL-17a inhibitors and small molecule inhibitors targeting PDE4 have been shown to be useful to treat PsA and PsO with both, and AS with the former. However, real-world evidence of IBD co-occurrence in pts with CID treated with IL-17a/PDE4 inhibitors is scarce.  To compare the incidence of IBD (i.e., Crohn’s disease and ulcerative colitis) between pts with CID not treated with a biologic agent and those treated with IL-17a/PDE4 inhibitors.

Methods: Adults with ≥2 claims with a diagnosis of either RA, PsA, AS, or PsO and ≥12 months of continuous health plan enrollment pre- (baseline period) and post-index date (random date among CID claims) were selected from the MarketScan® Research Database (1/2010-7/2017). Pts with cancer treated with rituximab or ofatumumab, with a transplant, or with ≥2 baseline claims with a diagnosis of IBD were excluded. The 1-year and 2-year incidence of IBD (defined as ≥2 IBD claims) was evaluated post-index among pts with no baseline claim for biologics and pts treated with IL-17a/PDE4 inhibitors during the baseline period. Comparison of IBD incidence between the two cohorts was done using a logistic regression model adjusting for baseline characteristics (including type of CID).

Results: In total, 424,767 pts were not treated with biologics (mean age: 54.4 years; 63.0% female) and 2,489 were treated with IL-17a/PDE4 inhibitors (mean age: 50.3 years; 54.6% female). The 1-year incidence was 0.7% in pts treated with IL-17a/PDE4 inhibitors and 0.5% in pts not treated with biologics (unadjusted odds ratio [OR]=1.54, P=0.0680). Among pts with ≥2 years post-index (no biologics: n=208,853; IL-17a/PDE-4: n=362), the 2-year incidence was 1.7% in pts treated with IL-17a/PDE4 inhibitors and 0.8% in pts not treated with biologics (unadjusted OR=2.16, P=0.0625). After adjustment, pts treated with IL-17a/PDE4 inhibitors were more likely to develop IBD than pts not treated with biologics at both 1 year (adjusted OR=1.77, P=0.0187) and 2 years (adjusted OR=2.29, P=0.0477). Similar trends were found when excluding pts with RA only (1-year incidence: adjusted OR=1.80, p=0.0161; 2-year incidence: adjusted OR=2.32, p=0.0438).

Conclusion: Higher IBD incidence was found in CID pts treated with IL-17a/PDE4 inhibitors compared to those not treated with biologics.