(11) The Risk of Serious Infection in Crohn's Disease Patients Treated with Biologics: An External Comparator Cohort Study

Sunday, August 28, 2022

8:00 AM – 1:45 PM CEST

Location: Hall C

Publication Number: 1056

Presenting Author(s)

Nai-Yu Chen
– NCKU Institute of Clinical Pharmacy and Pharmaceutical Sciences, Tainan, Taiwan

Co-Author(s)

Chiao-Hsiung Chuang
– Department of Internal Medicine, Medical College and Hospital, National Cheng Kung University, Tainan, Taiwan, Taiwan (Republic of China)
Yu-Ching Chang
– Health Outcome Research Center, National Cheng Kung University, Tainan, Taiwan, Taiwan (Republic of China)
Ching-Lan Cheng
– School of Pharmacy and, Institute of Clinical Pharmacy and Pharmaceutical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan, Taiwan (Republic of China)

Background: Although biologicals were reimbursed for Crohn's disease patients in Taiwan since 2011, serious infection during biological treatment is still controversial, because the indications for biologicals are narrow and not likely to be present in parallel comparison groups.

Objectives: To evaluate the serious infection associated with biologicals in Crohn’s disease (CD) using external comparation group.

Methods: A retrospective cohort study was conducted using National Health Insurance data (NHID) from 2003-2018. We compared CD patients on biological therapy in the post-biological era (POB, 2011-2018) with a historical control group as biologics-naïve CD patients in pre-biological era (PRB, 2003-2010). For the POB, the index date was the 1st biological prescription date. For PRB, the index date was randomly assigned by computer according to the duration between the 1st CD-related medication and 1st biologics date of the POB. Study outcome defined as mild infections (outpatients visit) and severe infection (emergency room visit, or hospitalization). To control the measurable confounding factors, inverse probability of treatment weighting (IPTW) estimation was applied. The hazard ratio (HR) and 95% confidence interval (CI) were calculated by cox regression with intention-to-treat (ITT) and as-treated (AT) analysis.

Results: A total of 506 CD patients (PRB: 286; POB: 220) were included. The mean age was respectively 40 (14.5) years in PRB and 37.2 (14.2) years in POB. The baseline characteristics was similar between 2 eras. The cumulative probability of infections was no significantly increased during biologic use (log-rank test, mild infection p=0.15, severe infection p=0.75). The incidence rate (per 1000 person-years) in mild infection was 1376 in POB, and 1701 in PRB and severe infection was 231 in POB, and 230 in PRB, respectively. After IPTW with ITT analysis, there was no increased risk in mild (HR, 0.85; 95% CI, 0.68-1.06) or sever (HR, 1.09; 95% CI,0.71-1.69) infection during biologics treatment period. We also had the same finding with AT analysis. Stratification in the site of infection or restriction patients with previous conventional medication, there was no significant risk for mild or severe infection.

Conclusions: Compared to conventional therapy, biological therapy in CD patients does not increase infection risk. The result provided evidence in safety profile when selecting medications for CD patients.