Microbiota Transplant Therapy to Prevent HE Recurrence in a Phase 2B Multi-Center Trial of Veterans With Cirrhosis

Wartime injuries as well as metabolic disorders can result in liver injury directly or indirectly through PTSD, metabolic disorders, and/or alcohol misuse. These liver injuries culminate in cirrhosis, which affects 4.9 million patients in the US, >80,000 of whom are Veterans. Moreover, numerous Veterans with cirrhosis remain undiagnosed, suggesting these numbers are an underestimation. A major complication of cirrhosis, which is exacerbated by alcohol misuse and PTSD, is hepatic encephalopathy (HE), which affects >50% of Veterans with cirrhosis. Current HE therapies are lactulose (inexpensive but difficult to tolerate) and rifaximin (expensive and second line). However, despite these therapies, a large group of patients have recurrent HE episodes. These recurrences worsen clinical (readmissions, falls, death), psychosocial (cumulative brain injury, poor quality of life, disability, stress on the family), and financial outcomes to the patients, families, and the VHA. Microbiota transplant therapy (MTT) or fecal microbiota transplant (FMT) has the potential to interrupt this cycle. There are Phase 1 and Phase 2a randomized controlled trials (RCTs) published that defined safe and acceptable MTT routes for Veterans with HE. MTT was acceptable to most Veterans who were approached. However, the impact of MTT in preventing HE recurrence in a multi-center context is unclear, especially in those on lactulose only versus those on rifaximin.

The central hypothesis is: Microbial transplant therapy delivered through capsules will significantly reduce the rate of HE recurrence regardless of lactulose or rifaximin use compared to placebo in a multi-center double-blind, placebo-controlled, randomized clinical trial of Veterans with cirrhosis.

In a 6-month double-blind, multi-center, placebo-controlled, randomized clinical trial in Veterans with cirrhosis and HE on lactulose or rifaximin, these specific aims will be used to test this hypothesis:

Aim 1:Determine the rate of HE recurrence in MTT versus placebo-randomized groups: Patients from each site will be randomized 1:1 into receiving MTT or placebo capsules, which will be administered twice a day for 2 weeks. Patients will be followed monthly for 6 months. Recurrence of HE will be defined using standard criteria and will be the primary outcome. Stratification by lactulose use alone or lactulose and rifaximin will be performed.

Aim 2: Determine the effect of MTT on all-cause hospitalizations, death, and liver transplant compared to placebo. This analysis will study safety outcomes other than HE between the groups.

Aim 3: Determine the impact of MTT on systemic inflammation, microbial community structure and function, and donor engraftment over time compared to placebo. In MTT and placebo groups, stool microbiome will be studied for donor engraftment, microbiome structure (stool metagenomics), and microbiome function (targeted and untargeted metabolomics from stool and blood) to determine impact of MTT on recipients and clinical outcomes. Systemic inflammatory changes and antibiotic resistance microbial genes will be analyzed. Individual donor-recipient matching will be studied to evaluate best combinations.

Aim 4: Determine the impact of MTT on cognitive testing, health-related quality of life, and daily function. Cognitive testing, validated PROs, and Veterans' input on FMT and the trial will be analyzed.

Based on favorable results of our single-center phase 2A trial, 162 patients (half on lactulose alone and half on rifaximin) across the three sites will be included. Compound MTP-101C, which is a standardized form of MTT targeting delivery into the distal intestine, will be used. Three rationally selected donors with high Lachnospiraceae relative abundance to maximize engraftment and study donor-recipient matching will be selected.