Different Treatment Frequencies for Hepatic Fibrosis Due to Schistosomiasis: an RCT

The overarching goals of this proposal are to conduct a double blind, randomized controlled trial (RCT) (Phase III) among N=600 participants ages 15-40 in Lake Albert, Uganda, that will examine varying frequencies of treatment with Praziquantel (standard 40 mg/kg PO every 4 months or annually for three years) to identify approaches that best reverse or halt fibrosis as captured by ultrasound annually.

After excluding other causes of hepatic fibrosis, we will randomize/enroll N = 600 participants for the RCT (N = 150 individuals in each age and sex strata (4 sub-groups)) who have compensated schistosomal liver fibrosis based on the WHO "Niamey" ultrasound protocol for S. mansoni.

Using stratified randomization by subgroup treatment arms are as follows:

• Annual treatment (standard) arm: The annual treatment study arm will receive active study agent (PZQ at 40 mg/kg) at baseline and one, two, and three years post randomization and placebo at intervening 4 month visits (i.e. 4, 8, 16, 20, 28, 32 months post baseline).
• Every 4 months treatment (intervention) arm: This arm will receive praziquantel at a dose of 40 mg/kg every 4 months for 3 years. (i.e. at 4, 8, 12, 16, 20, 24, 28, 32 and 36 months post baseline).

Randomization and blinding The trial statistician will generate randomization codes by study number in blocks for each age/sex group and share with the pharmacist. Because the placebo and praziquantel tablets will be matched, allocation to a given study arm will be concealed to participants and study staff, including ultra-sonographers who are assessing study outcomes.

The overall goals of this trial are to examine varying frequencies of treatment with Praziquantel (every 4 months or annually for three years) to identify approaches that best reverse or halt fibrosis as captured by ultrasound annually. We will also identify novel biomarkers using our multiplexed assay which captures over 40 analytes involved in fibro-degradation and fibro-proliferation, which best predict progression of fibrosis.

The primary objective for the trial will be to assess the impact of PZQ dosed annually vs every 4 months over three years on grade of fibrosis as captured by the Niamey protocol from baseline to three years with ultrasound performed annually. The primary endpoint is improvement in grade of fibrosis (any improvement) during this three-year period of follow up. Grades by image pattern are below and improvement, stability or worsening is based on changes in these categories from baseline.

Secondary objectives are to:

• assess the impact PZQ administered annually versus every 4 months over three years on presence and of severity portal hypertension status (absent, dilated or severely dilated) based on portal vein quotient
• assess the impact of PZQ administered annually versus every 4 months on grade of hepatic fibrosis after one and two years.
• assess the impact of PZQ administered annually versus every 4 months presence and severity (absent, dilated, severely dilated) of portal hypertension after one and two years.
• evaluate the impact of two different treatment frequencies with Praziquantel (40 mg/kg) annually or every 4 months on key biomarkers of fibrosis

The primary outcome will be any improvement in grade of fibrosis (mild, moderate, severe) from baseline to study close out at three years dichotomized as Yes/No improvement to produce a rate of improvement across study arms.

Hepatic Fibrosis Grade: We will employ the "Niamey" protocol, for the assessment of fibrosis in the context of S. mansoni. Hepatosplenic schistosomiasis (HSS) encompasses a characteristic type of portal fibrosis, also called Symmer's clay pipe fibrosis or periportal fibrosis, and its resulting complications such as portal hypertension. The Niamey protocol has a detailed scoring system for fibrosis that is based on both "image pattern" and degree of periportal fibrosis. For S. mansoni, fibrosis is characterized by grades (B- F) with grades C to F constituting mild to severe grades of fibrosis.

Since image pattern B is not specific to schistosomiasis, individuals with pattern B will not be included. Fibrosis will be graded with respect to location (periphery (C) & central (D, E, F)). These scores culminate in a severity grading that maps to mild, moderate, and severe.

Mild: Image Pattern C Moderate: Image Pattern D Severe: Image pattern E or F

Improvement is defined as change from baseline status as follows:

• E or F to D (severe to moderate)
• E or F to C (severe to mild)
• E or F to A or B (severe to none/non specific)
• D to C (moderate to mild)
• D to A or B (moderate to none/non specific)
• C to A or B (mild to none/non specific) Stability is defined as no change from overall group (mild (C), moderate (D) or severe (E or F)) at defined follow up timepoints.

Progression is defined as change in baseline status as follows:

• C to D (mild to moderate)
• C to E or F (Mild to severe)
• D to E or F (Moderate to Severe)

Clinical secondary outcomes include change in grade of portal hypertension from baseline.

Portal Hypertension: We will separately assess whether there is evidence of significant portal hypertension by ultrasound as per the Niamey protocol. The presence of portal hypertension will be defined by the portal vein quotient (adjusted for height). A quotient greater than 7.5 is indicative of portal hypertension. It's severity is assessed as absent, dilated or severely dilated (Normal: ≤ 7.5 mm/m, Dilated: 7.6 - 10 mm/m, Severely dilated: > 10 mm/m)

Secondary outcomes include:

• Improvement in severity of portal hypertension after three years and
• improvement or stability in grade of fibrosis (as described above) after one and two years
• Improvement in severity of portal hypertension after one and two years

We will also address the following exploratory objectives which do not represent clinical endpoints for the trial but rather identify key fibrosis biomarkers that predict the presence of hepatic fibrosis and its progression from baseline. These secondary/exploratory outcomes will use the aforementioned definition of change in fibrosis grade from baseline.

At baseline, we will cross-sectionally evaluate fibrosis biomarkers with a multiplexed assay "FibroPlex" (e.g microRNAs, hyaluronic acid) with over 40 analytes using Area Under the Curve Analyses to identify specific biomarkers and "cut offs" which accurately identify individuals with varying stages of liver fibrosis by ultrasound. We will then longitudinally evaluate fibrosis biomarkers that identify risk of progression from mild-moderate to higher grades of fibrosis as assessed by ultrasound annually stratified by treatment allocation among the N=600 RCT participants. This will allow identification of individuals at greatest risk of fibrosis progression before overt symptoms and while still reversible.

Inclusion criteria

• S. mansoni infection as determined by urine Circulating Cathodic Antigen (CCA)
• Otherwise healthy as determined by history and physical examination conducted by the study clinician
• Not Pregnant
• Age 15-40 years
• Consent for individuals 18 years of age and older, and parental consent and adolescent assent for participants ages 15-17 years.
• The presence of hepatic fibrosis due to S. mansoni (Niamey protocol grade C-F) and compensated (without late-stage portal hypertension) after ruling out other causes of hepatic fibrosis as below.

Exclusion criteria

• . History of upper gastrointestinal bleeding
• Hepatic fibrosis that is not deemed to be due to schistosomiasis based on ultrasound and hepatitis serologies. For example, alcoholic cirrhosis or presence of chronic Hepatitis B or C by point of care test
• Known neurocysticercosis or ocular cysticercosis