NNITS-Nitazoxanide for Norovirus in Transplant Patients Study

This is a phase 2 multi-center, double-blind, placebo-controlled study of the efficacy and safety of nitazoxanide for the treatment of solid organ and hematopoietic stem cell transplant recipients with symptomatic diarrhea due to Norovirus. The study involves a total of 160 Hematopoietic Stem Cell or Solid Organ transplant recipients, equal to or greater than 12 years of age with diagnosis of Norovirus who will be selected and randomly assigned (1:1) into two treatment groups: nitazoxanide or placebo. The study duration is approximately 60 months and subject participation duration is approximately 6 months. Given the safety of prolonged therapy with nitazoxanide, lack of interactions with common post-transplant medications, putative antiviral activity and prolonged duration of viral shedding we are assessing 56 doses of therapy. The longitudinal monitoring phase will provide useful information on the course of host and viral responses in subjects with chronic Norovirus infection with and without treatment. Randomization will be stratified by age group (pediatric (12 through 17 years) vs. adult (greater than or equal to 18 years)), chronicity of Norovirus-associated symptoms (acute (less than 14 days) vs. chronic (greater than or equal to 14 days)) and transplant type (solid organ (SOT)) vs. hematopoietic stem cell transplant (HSCT)). Enrolled subjects will participate in 2 phases of the study: Treatment Phase, which will include dosing with the assigned study agent for 28 days. Longitudinal Monitoring Phase which will include telephone call on Days 35, 53, 113, 173. Primary objective is 1) to assess the clinical efficacy of nitazoxanide for the management of acute and chronic Norovirus in transplant recipients. Secondary Objectives are 1) to assess the virologic efficacy of nitazoxanide and 2) to assess the safety of nitazoxanide for the management of acute and chronic Norovirus in transplant recipients.