The European Crohn’s and Colitis Organisation Congress 2026 focused on holistic care for inflammatory bowel disease. Here, Andrea Porter outlines some of the main takeaways from research into ustekinumab biosimilar adoption.

The use of biologic therapies continues to expand across hospital specialties, particularly in gastroenterology where their use in inflammatory bowel disease (IBD) is prominent.

With increasing pressure on medicines budgets, the need for safe, effective and well-managed biosimilar adoption has never been more important.

Several pieces of research presented at the European Crohn’s and Colitis Organisation Congress (ECCO’26) focused on this theme – specifically the growing role of biosimilar ustekinumab in IBD and its adoption and use in clinical practice.

Promising real-world induction outcomes in Crohn’s disease

A single-centre prospective cohort study presented by University Hospital Southampton NHS Foundation Trust evaluated induction outcomes with the ustekinumab biosimilar Wezenla (ABP 654) in patients with Crohn’s disease.

The study included 37 patients started on this immunosuppressant biosimilar, with 36 completing the 16-week induction phase and one discontinuing due to primary non-response. The cohort had a median age of 45 years and a median disease duration of seven years, indicating a population with established disease.

Nearly half (49%) were biologic-naive, while 51% had prior exposure to anti-tumour necrosis factor (anti-TNF) therapies and 8% had previously received vedolizumab.

Baseline characteristics also highlighted the cohort's complexity, with 16% receiving corticosteroids at initiation and 11% having perianal disease. Smoking status varied, with 46% never smokers, 46% ex-smokers and 8% current smokers.

Clinical outcomes improved throughout the induction period. Median modified Harvey–Bradshaw Index scores decreased from 5 at baseline to 2.5 at week 16, by which time 83% of patients remaining on treatment were in remission or had only mild disease activity.

Patient-reported outcomes showed similar gains. Median IBD-Control-8 scores increased from seven at baseline to 12 at week 16, while IBD-Control visual analogue scale scores rose from 50 to 80, suggesting meaningful improvements in quality of life.

Although constrained by its small sample size and single-centre design, the study offers early real-world evidence supporting the effectiveness and tolerability of biosimilar ustekinumab during induction.

Reference: Elms C et al. Single centre induction outcomes with biosimilar ustekinumab (Wezenla: ABP 654) in patients with Crohn’s disease. Poster P0974.

Biosimilar switching maintains disease control

A large UK multicentre study assessed clinical outcomes following biosimilar switching across 545 patients with IBD across 12 NHS sites, representing a broad real-world population.

Of these, 85% had Crohn’s disease and 15% had ulcerative colitis, with a slight female predominance (54%).

Most patients (81%) had previously received anti-TNF therapy, while 16% had been treated with vedolizumab and 12% had exposure to both, reflecting a treatment-experienced cohort.

Three ustekinumab biosimilars were used according to local prescribing policies, with Wezenla accounting for the majority (77%), followed by Pyzchiva (15%) and Uzpruvo (8%). At the time of switching, 3% of patients were receiving corticosteroids.

Between 12 and 24 weeks post-switch, there were no statistically significant differences in biochemical markers, including C-reactive protein and faecal calprotectin, or in clinical disease activity indices such as the Harvey–Bradshaw Index for Crohn’s disease and the Simple Clinical Colitis Activity Index for ulcerative colitis.

Although physician global assessment scores increased (P=0.0001), the absolute change was small (0.31 to 0.51), with a median difference of zero, suggesting limited clinical relevance.

Treatment persistence was high, with 91% of patients remaining on biosimilar therapy. Among the 9% who discontinued, 7% switched to an alternative treatment and 2% reverted to the originator.

Adverse drug reactions were reported in 6% of patients and 0.9% reported an injection-site reaction, indicating good tolerability.

Overall, the findings suggest that switching to biosimilar ustekinumab does not adversely affect disease control and is associated with high persistence rates.

The authors highlighted the need for longer-term follow-up, including a planned 12-month analysis, to confirm sustained effectiveness and safety.

Reference: Sharma E et al. Switching from ustekinumab originator to biosimilar: No adverse impact on inflammatory bowel disease control and well tolerated by patients in a UK multicentre study. Poster P1139.

MDT biosimilar implementation

An implementation study from Oxford University Hospitals NHS Foundation Trust described a structured, multidisciplinary approach to switching patients from originator ustekinumab in routine clinical practice.

Between October 2024 and April 2025, a total of 482 patients were prescribed biosimilar ustekinumab. Of these, 79% were switched from the originator at the point of prescription renewal, while 21% were newly initiated on treatment with a biosimilar.

The switching programme was pharmacy led and involved coordination between pharmacists, gastroenterologists and IBD specialist nurses.

Key implementation steps included biosimilar selection based on cost and formulation, patient notification via clinician-led communication, updates to homecare delivery services, and provision of support mechanisms such as helplines and face-to-face clinics.

Patient engagement was high, with only 2.6% (n=10) contacting the clinical team with concerns. These contacts were mostly related to perceived differences in efficacy or safety, or confusion about the concept of a biosimilar. Half of these patients were reviewed in clinic, and all ultimately agreed to proceed with the switch.

Switch-back rates were low. Only one patient reverted to the originator due to side effects, while 3.7% (n=18) required a change to alternative therapy due to loss of response.

Clear communication, patient reassurance and multidisciplinary collaboration were identified as vital to the programme’s success, and this structured approach supported efficient implementation that aligned with NHS priorities to promote the adoption of cost-effective biologic therapies.

Reference: Cripps S, Sanford J, Azzu H. Implementing a biosimilar switch. Poster P0646.

The bottom line

Together, these ECCO’26 presentations strengthen the growing evidence supporting biosimilar ustekinumab in IBD. Across settings such as induction, switching and implementation, it has consistently demonstrated effectiveness, stable disease management and good tolerability in real-world populations.

Although longer-term comparative data are still needed, the findings here endorse broader use of biosimilars in routine clinical practice, with possible advantages for NHS sustainability and resource efficiency.

This is the first in a series of articles examining key themes from ECCO’26, so stay tuned for our next instalments on advances in digital and precision technologies, new management strategies during pregnancy and in paediatric disease, and the growing importance of pharmacy in delivering person-centred care in IBD.