Background and importance According to the EMA product information, in Crohn’s disease (CD), ustekinumab is dosed first by intravenous administration. Patients should then continue with 90 mg ustekinumab subcutaneous every 8 (q8W) or 12 (q12W) weeks depending on the response to treatment.

Aim and objectives To review the use of ustekinumab in patients with CD in a third level hospital and identify those with sustained remission that are susceptible to optimisation, evaluating the associated economic impact.

Material and methods This was a descriptive cross sectional study. Patients from the digestive medicine service under active treatment with ustekinumab in September 2019 and who were treated in the hospital outpatient pharmacy were included. Variables collected from the clinical history were: demographic (sex and age), pharmacotherapeutic (previous biological treatment, treatment time with ustekinumab, dosage) and clinical (response to treatment according to the prescriber). The response to treatment was classified based on the presence or absence of a sustained response (>4 months of symptomatic stability with the same dosage schedule). Additionally, the economic impact associated with optimisation of the administration interval in patients with a sustained response was determined.

Results Thirty patients with CD under active treatment with subcutaneous ustekinumab were included: 90% were men, with a mean age (range) of 48 years (18–75). The average time in treatment with ustekinumab was 11 months. The majority of patients had received at least one prior biological treatment (an integrin α4β7 inhibitor drug (n=8), a tumour necrosis factor antagonist agent (anti-TNF) (n=15) and two anti-TNF (n=3)) and in two cases ustekinumab was the first biological therapy.

At the time of the study, the maintenance dose in the majority of cases was 90 mg q8W (n=23), followed by q4W (n=5) and q12W (n=2) administration. Nine patients (30%) were identified in whom clinical stability was observed in the last 4 months and, therefore, could be candidates for an extension of the dosage interval (from q4W to q8W (n=1) and from q8W to q12W (n=9)). A potential saving of 75 000€ (13%) was estimated in the event that the recommendation to optimise treatment was followed in 100% of patients with a sustained response.

Conclusion and relevance The most common drug regimen for ustekinumab in CD was 90 mg q8W. However, 17% of patients required intensification of the dosage. A significant number of patients showed clinical stability and could be candidates for treatment optimisation with close follow-up by the multidisciplinary team. Optimisation could mean significant economic savings.

References and/or acknowledgements To my workmates.

No conflict of interest.