Authors (including presenting author) :
Luk Karen, Sze SF, Hui YT
Affiliation :
Department of Medicine, Queen Elizabeth Hospital
Introduction :
The incidence of inflammatory bowel disease (IBD) has increased in the last two decades in Hong Kong . With the introduction of new classes of biologic in the Hospital Authority Drug Formulary (HADF), the trend on using biologic has changed significantly . However, data on predictive factors of response to biologics and side effect profile are lacking in Hong Kong.
Objectives :
The primary outcome of this study was the number of Crohn's Disease (CD) patients achieving response at 52 weeks after initiation of therapy. The secondary outcome was the proportion of responders at 26 weeks.
Methodology :
Patients with a confirmed diagnosis of Crohn’s disease (CD) from year 1981 to 2016 were identified from a territory wide Hong Kong IBD registry (HKIBDR) involving 13 public hospitals. A total of 1114 CD patients were identified, in which 311 CD patients received biologic therapy from January 2001 till December 2018. Electronic medical records of the Clinical Data Analysis and Reporting System (CDARS) of the Hong Kong Hospital Authority were used to collect relevant data. The electronic record of each included CD patient was reviewed manually. Patients were followed up from the date of starting biologics (infliximab, adalimumab, vedolizumab and ustekinumab) till the end of 2018.
Result & Outcome :
Responders were defined as those who remained on therapy at week 52 after initiation of biologics, who has weaned off steroids and remained steroid free at week 52, who were not hospitalized due CD-related illnesses and who did not receive any CD-related surgeries in the 52-week period. As the patient records were reviewed retrospectively, more objective measurements of disease activity by the Crohn’s Disease Activity Index or the Harvey Bradshaw Index were not documented for all patients at each visit. The persistence on therapy was hence used to estimate response to therapy as patients were unlikely to remain on the potent and expensive therapy without prescription of breakthrough steroids should they receive no clinical benefit. From 2001 to 2018, 311 CD patients received biologics, with the number increasing from 2 in 2001 to 266 in 2018 . Seventy two patients (23.2%) utilized >1 biologic and failure to achieve clinical remission was the commonest reason for switching therapy. Allergic reaction was the most frequently encountered side effect (7.9%). The overall rate of infection and gastrointestinal malignancy was 8.85% and 0.013% respectively. A total of 164 (53.2%) of patients achieved response to biologic therapy . Concomitant use of corticosteroids (Odds Ratio (OR) 0.180, confidence interval ( CI 0.11-0.31, p < 0.001 ) and number of previous hospital admissions (OR 0.887 ,95% CI 0.82-0.96 , p < 0.001) were associated with non-response.
