Background and importance Clostridium difficile is the most common cause of infectious diarrhoea in hospitalied patients. Immunocompromised patients usually present recurrences after antibiotic theraphy. Bezlotoxumab is a human monoclonal antibody that binds C. difficile toxin B, approved for prevention of recurrent C. difficile infection (CDI) in high-risk patients (older than 65 years, history of recurrences in the last 6 months, infection with a hypervirulent strain).

Aim and objectives The aim of this study was to assess the effectiveness of bezlotoxumab in patients from a third-level hospital with CDI.

Material and methods Observational retrospective study from October 2018 to April 2021 was developed. Patients with CDI that were treated with bezlotoxumab were selected. Farmatools application, Farmis-Oncofarm and digital clinical history were used to record variables: age, gender, previous episodes of recurrence in the last 6 months and treatments, inmmune status, C. difficile strain, initial and sustained cure rate.

Results In the study period, 37 patients with median age 70 (16–85) years were included, 22 of them were older than 65 (59.5%) years: 16 women (43%) and 21 men (57%). Twelve (32.4%) patients had at least one previous episode of CDI and 26 (70.3%) were immunocompromised and 1 patient was diagnosed with having a hypervirulent C. difficile strain. Twenty-nine (78%) patients received previous treatment with oral vancomycin and/or metronidazole. The rates of initial and sustained clinical cure were 54% (n=20) and 81% (n=30), respectively. Five patients died before the sustained cure rate could be measured.

Conclusion and relevance The effectiveness obtained measured with the initial clinical cure was lower than the results described by the pivotal trial (54% vs 80%) and the sustained clinical cure was higher (81% vs 64%). These results showed that bezlotoxumab appears to be an effective alternative to patients at high risk of recurrent CDI, although further studies including more patients would give more information about the use of this new drug.

References and/or acknowledgements https://www.aemps.gob.es/medicamentosUsoHumano/informesPublicos/docs/IPT-bezlotoxumab-Zinplava-inf-Clostridium-difficile.pdf

https://www.nejm.org/doi/full/10.1056/NEJMoa1602615

Conflict of interest No conflict of interest