Randomised Controlled Trial of Mechanistic Effects of Rifaximin in Cirrhosis and Chronic Hepatic Encephalopathy

Overview

The study will be designed and conducted as a double blind placebo controlled randomised controlled trial - Clinical Trial of an Investigational Medicinal Product.

This study will be performed on patients referred to King's Liver Unit for further assessment and management of chronic overt hepatic encephalopathy (≥ Grade 1) or with ≥2 episodes of overt hepatic encephalopathy in the previous 6 months.

The study will be performed on 50 patients with cirrhosis and chronic hepatic encephalopathy [25 Rifaximin and 25 placebo] aged between 18 and 75 years managed within the Liver Unit at King's College Hospital which is the largest tertiary Liver Transplant Centre within the UK. For the purposes of this study a patient will be considered to have cirrhosis if they fulfil 2 out of 3 diagnostic criteria of confirmatory liver histology, biochemistry and/or radiologic findings consistent with cirrhosis/portal hypertension, and are presenting with chronic persistent overt hepatic encephalopathy (≥ grade 1) or with ≥2 episodes of overt hepatic encephalopathy in the previous 6 months.

Patient demographics, clinical details (including Westhaven hepatic encephalopathy grade) and blood haematology, biochemistry (including venous ammonia), microbiology data and neutrophil function will be assessed and collated at baseline and following 30 and 90 days of Rifaximin therapy or placebo. Intestinal permeability will be assessed using the intestinal disaccharide test. Faecal microbiota analysis will be performed by deep pyrosequencing techniques and plasma endotoxemia will be measured (lipopolysaccharide levels) with bacterial DNA quantification as a marker of bacterial translocation. These will all be measured at 3 time points: baseline and at 30 and 90 days after initiation of Rifaximin therapy or matching placebo.

Investigations

Patients will undergo intestinal functional tests within 7 days of recruitment, whereby they will be administered a test solution of not more than a cupful (150mls) of different types of non-absorbable sugars, which are drunk in liquid form by the participants. Prior to ingestion, baseline samples will be obtained as follows:

i) blood samples - for analysis of intestinal & immune (dys)function, and metabonomic analysis ii) urine sample - for intestinal (dys)function & metabonomic analysis iii) stool sample - for faecal biomarker and microbiota analysis

1v) ascitic sample (if clinically indicated) - surplus fluid will be analysed for bacterial translocation and immune (dys)function

Once the test solution has been ingested, blood samples will be obtained via a cannula which is placed in a vein, usually in the arm, prior to the start of the test, to allow further sampling without causing discomfort to the patient. A total of 15 samples will be obtained over a 5 hour period, with intervals ranging between 20-30mins, of not more than 6mls per sample. At the end of the test, at a 5 hour interval, a further urine sample will be collected to allow for intestinal functional testing. This is exactly the same procedure as that specified in the approved 'The Gut-Liver Axis in Liver Disease & Liver Transplantation' study (REC ref: 12/LO/1417).

Where participants are undergoing sampling of ascitic fluid for clinical reasons any fluid in excess of pathology's requirements will be analysed along with peripheral blood samples. Ascitic samples will only be taken from patients in whom a decision has been made to take these samples for clinical reasons (this decision will not be that of the investigator). No increased volume of such sample would be required.

Clinical outcomes (development of recurrent overt hepatic encephalopathy, organ failure and infection) will be recorded for a total of 90 days.

Analysis of samples - sites

Blood, urine and ascitic samples will be analysed in the Institute of Liver Studies and King's College Hospital laboratories where various tests to determine intestinal and immune function will be undertaken. Stool samples will be analysed both at laboratories at King's College Hospital and at the Franklin-Wilkins Building, King's College London, where faecal biomarkers and faecal microbiota analyses will be performed, respectively. Metabolic analyses for metabonomic profiling will be carried out at Imperial College London (both at St Mary's Hospital and at the South Kensington Campus).

Protocol

A more detailed list of the tests and analyses to be performed is to be found in the protocol. Study-specific flow charts have also been provided for a step-by-step representation of the study, visually representing the study process including participant recruitment, randomisation, sampling protocols and analyses at the three time points and follow-up visits.

Inclusion criteria

• Patients with established cirrhosis complicated by hepatic encephalopathy
• For the purposes of this study a patient will be considered to have cirrhosis if they fulfil two out of the three diagnostic criteria of confirmatory liver histology, biochemistry and/or radiologic findings consistent with cirrhosis/portal hypertension, and
• are presenting with chronic persistent overt hepatic encephalopathy (≥ grade 1) or with ≥2 episodes of overt hepatic encephalopathy in the previous 6 months.

Exclusion criteria

• Age ≤18 or ≥75.
• Evidence of disseminated malignancy.
• Known coeliac or inflammatory bowel disease.
• Evidence of intestinal failure, intestinal obstruction and / or previous bowel resection.
• Pre-existing immunosuppressive states including HIV infection and chronic granulomatous diseases.
• Anti-inflammatory drug use e.g non-steroidals and immunomodulatory drug use e.g. prednisolone and azathioprine.
• Known hypersensitivity to rifaximin or rifamycin-derivatives
• Already receiving concomitant oral or parenteral antibiotic therapy e.g norfloxacin.
• Infection with clostridium difficile or stool testing positive for clostridium difficile toxin in the previous 3 months.
• Pregnancy or breast feeding women