Capsule Sponge Study in Eosinophilic Oesophagitis

Eosinophilic oesophagitis is a condition characterised by symptoms of dysphagia (swallowing difficulties) and/or food impaction in adults, with oesophageal biopsies (histology) showing a peak eosinophil count of >15 eosinophils/high power field (or >15 eosinophils/0.3mm2 or >60 eosinophils / mm2), and the absence of other causes of oesophageal.

Evidence suggests that if inadequately treated there is increased risk of oesophageal fibrosis and stricture formation that can lead to progressive dysphagia, food bolus obstruction (food blockages) and increased morbidity. The degree of eosinophil infiltration in the mucosa is thought to reflect the disease activity better than patient symptoms.

Current guidelines from Europe and newly published national guidelines from the British Society of Gastroenterology from the UK recommend reassessment of oesophageal eosinophilia after treatment to ensure remission This has traditionally involved repeating gastroscopies after each treatment (diet -after each food group, proton pump inhibitor (PPI), topical steroids) which is unpleasant for patients, expensive and labour intensive as well as producing a large carbon footprint.

Since the start of the COVID-19 pandemic in January 2020 there has been restricted or delayed access to gastroscopy nationally and consequently many patients with EOE have had their repeat gastroscopies cancelled or postponed, increasing the risk of complications from undertreated disease.

Capsule sponge (Cytosponge and Endosign being the current commercially produced example in the UK) is an oesophageal cell sampling device that is a 'pill on a string'. The patient swallows the pill with water and the sponge expands in the stomach. The nurse withdraws the string after 7 minutes and the sponge collects oesophageal cells on withdrawal. The sponge is sent for cytological analysis that identifies cells that can be stained for various biomarkers of Barrett's oesophagus (TFF3) and markers of dysplasia (p53 and atypia) as well as the opportunity to look at inflammation and in particular in this setting to assess the number of eosinophils and other histological and inflammatory markers supporting a diagnosis of EOE.

The use of Capsule sponge in the diagnosis and monitoring of EOE has been described as an alternative to gastroscopy and a quantitative eosinophil count is possible on cytology to allow sequential assessment. The eosinophil count on cytology samples from Capsule sponge are similar to biopsies taken from the same patient at the same time, when assessed per high power field (area of 0.3mm2) in a single study.

Over 10,000 Capsule sponge procedures have now been performed in the UK. The Capsule sponge service at East and North Herts trust has now performed over 1000 procedures making the trust the largest UK single site experience.

The trial population will involve adult patients over 18 years who are known to have a histological diagnosis of EOE and are under follow up at East and North Herts NHS trust.

Preclinical/Clinical Data The use of Capsule sponge in the monitoring of EOE has been described in a single prospective cross sectional 2-centre study in USA .

There have been no studies to date assessing the clinical value of Capsule sponge in monitoring disease activity or response to treatment in adults in a real-world setting.

Rationale

• Does the use of Capsule sponge instead of endoscopy and biopsies in monitoring known non-stenotic EOE provide sufficient information to affect management decisions in a real-world setting?
• Current practice to monitor EOE disease activity with endoscopy and biopsies has been severely affected by the COVID19 pandemic resulting in delays to treatment and the risk of progressive stenotic disease and morbidity.
• Gastroscopy is invasive, expensive, unpleasant and aerosol generating whilst Capsule sponge is cheaper, much less invasive does not require sedation and is preferred by patients and carries a lower carbon footprint.

STUDY OBJECTIVES AND DESIGN Objectives Primary objectives: Does Capsule sponge instead of endoscopy and biopsies in monitoring known non stenotic EOE provide sufficient information to affect management decisions in a real-world setting? Do patients show a preference for Capsule sponge over endoscopy and biopsies?

Secondary objectives:

• Subgroup analysis by current treatment
• Do Symptom scores reflect eosinophil count and other markers of inflammation on cytology and histology?
• Complications
• Failure to swallow rate
• Inadequate cytology rate
• Gastroscopy rate by 1year if not done simultaneously
• Potential Cost savings compared with gastroscopy

Endpoints/outcomes

Primary Endpoints/outcomes:

Descriptive analysis of management decision made as a result of the Capsule sponge findings Patient preference for Capsule sponge or gastroscopy

Secondary Endpoints/outcomes:

• Subgroup analysis by current treatment (diet/PPI/topical steroid/combination/no treatment)
• Correlation between Symptom scores and eosinophil count and other markers of inflammation on cytology and histology
• Additional cytological findings of EOE activity and inflammation
• Other cytological findings: Barrett's oesophagus/dysplasia/other diagnoses
• Number of Complications
• Failure to swallow rate
• Inadequate cytology rate
• Gastroscopy rate if not done simultaneously
• Cost savings
• Patient satisfaction and pain scores

Study Design

• Purpose of research To identify a suitable alternative to endoscopic biopsies for monitoring patients with non-stenotic EOE.
• Real-world prospective pragmatic interventional study in a single district general hospital secondary care setting with quantitative and qualitative outcome measures. Design chosen as pragmatic and comparative control study with endoscopy would be impractical due to COVID backlog, cost and such a study has already been performed
• Data collection methods:
• An excel database of patients with EOE will be established and used as a screening log.

With demographic data, date of diagnosis, date of previous endoscopies, endoscopic findings (EREFS criteria if documented) eosinophil count on previous histology and any other histological supportive features, current and previous treatments documented. Reasons for ineligibility will also be documented.

The study will be discussed with eligible patients at their normal clinic appointment and for eligible patients who agree to enrol in the study:

The following will be sent to patient by email/post as preferred and the Capsule sponge service contact email and phone details:

• Eligible patients will be sent copies of the trust standard Capsule sponge procedure information leaflet.
• Copies of patient Information leaflet regarding the COSiE trial
• Study specific Consent form
• 2 week symptoms diary Dysphagia Symptom Questionnaire (DSQ)

The following will be administered with the patient on the day of the Capsule sponge procedure:

• Capsule sponge eligibility and safety questionnaire
• Documentation of Current treatment and duration and compliance
• Patient satisfaction survey after procedure

Patient participation opinion group has been completed

Number of subjects A total of 100 -140 evaluable patients will be enrolled in the study. This is thought to be an achievable sufficiently large sample target given the prevalence of EOE in the catchment population. The PI runs a dedicated EOE teleclinic every month that sees approximately 12 patients. It is estimated that 2/3 of these would be eligible for Capsule sponge. In addition, other patients with EOE are also followed up in 5 other consultant gastroenterology clinics that would be eligible for the study.

Study Duration The length of time the study is expected to run over 2 years in order to recruit sufficiently large sample.