The effect of biosimilars in the management of Acute Severe Ulcerative Colitis
Grace Harkin, Áine Keogh, Eoin Slattery
Gastroenterology Department, University Hospital Galway
Biosimilars are an almost identical copy of biologic drugs that exhibit high molecular complexity manufactured by a different company. Because of potential cost savings they are of interest to health care policy makers. In 2015 our hospital became the first in Ireland to introduce a biosimilar (i.e. Inflectra®, Hospira, Lake Forest, IL, USA) for all new patients starting infliximab(IFX). Acute severe ulcerative colitis (ASUC) is a serious potentially life threatening illness requiring in-hospital rescue therapy with intravenous steroids and where unsuccessful a second line agent (commonly IFX) to prevent need for colectomy. While some data exists of the effectiveness and safety of biosimilars in general Inflammatory Bowel Disease (IBD) cohorts, no data exists on its use in ASUC.
To assess the impact of biosimilar IFX in patients presenting with ASUC needing rescue therapy.
We performed a retrospective observation-based cohort study on patients admitted to our institution with ASUC (as defined by Truelove and Witt’s criteria and Mayo score). Patients who failed to respond to intravenous steroid and then received biosimilar IFX as “rescue” therapy were included. Dosing was at the discretion of the individual clinician. Patients were followed-up in the usual clinical manner.
A total of 8 patients (5 female) have received biosimilar IFX for “rescue” therapy with ASUC. Median age was 36years (28-47years). All patients were admitted with severe disease as evidenced by a median Mayo score of 11, median CRP 86 (8-370), Albumin 31 (29-40) and Hb 10.7 (7.3-12.6). Median duration of disease prior to presentation was 1.9years (0.3-20.3years). Patients were followed-up for a median of 9.1months (range 1.5-12.9). Five patients were treated with combination therapy with Azathioprine. To date no patients receiving biosimilar IFX have undergone colectomy. No serious adverse events (infections etc.) were noted.
ASUC is a unique subset of IBD where evidence is evolving surrounding important differences in treatment regarding immunogenicity and pharmacokinetics. In this small cohort of ASUC patients, biosimilar IFX appeared to be at least as effective as its originator. No adverse events were noted or warning signals re: lack of effectiveness was demonstrated. Further follow-up and increasing experience is required.