Oral Fosamprenavir + Sodium Alginate for GERD

A Phase 2, Randomized, Double-blind, Placebo-controlled Trial of Fosamprenavir-Sodium Alginate Administered Orally for 8 Weeks to Patients With Proton Pump Inhibitor Refractory Gastroesophageal Reflux Disease

The goal of this clinical trial is to learn if study drug Fosamprenavir-Sodium Alginate (FOS-SA) administered orally improves symptoms for Proton Pump Inhibitor (PPI)-refractory Gastro Esophageal Reflux Disease (GERD).

The main questions it aims to answer are:

1. Does FOS-SA significantly improve heartburn severity over the 8-week treatment period
2. Does FOS-SA significantly improve regurgitation frequency over the 8-week treatment period
3. Does FOS-SA significantly improve symptoms of persistent GERD over the 8-week treatment period

Researchers will compare FOS-SA to a placebo (a look-alike substance that contains no active drug) to see if FOS-SA works to treat PPI-refractory GERD.

Participants will:

1. Take FOS-SA or placebo every day BID (twice a day) for 8 weeks
2. Visit the Adult Translational Research Unit (ATRU) seven times for consenting, screening, and checkups and tests
3. Keep a daily diary of their symptoms of persistent GERD

Study Overview

• Status: Not yet recruiting
• Conditions: Gastroesophageal Reflux Disease; Refractory Gastroesophageal Reflux Disease
• Intervention / Treatment: Drug: Fosamprenavir Calcium & Sodium Alginate; Other: Placebo

• Study Type: Interventional
• Enrollment (Estimated): 60
• Phase: Phase 2

Contacts and Locations

• Study Contact: Name: Ally Lesnick, BSc; Phone Number: 414-955-2659; Email: alesnick@mcw.edu
• Study Contact Backup: Name: Nikki Johnston, PhD.; Phone Number: 414-955-4075; Email: njohnston@mcw.edu

Study Locations

• United States
  • Wisconsin
    • Milwaukee, Wisconsin, United States, 53226
      • Medical College of Wisconsin
      • Contact: Ally Lesnick, BSc.; Phone Number: 414-955-2659; Email: alesnick@mcw.edu

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Patient aged 18-65 selected as candidate for anti-reflux surgery by study providers.
2. Patient has received, and continued having GERD symptoms during, standard-labeled dose, daily, PPI therapy for a minimum of 8 weeks before the Screening Visit.

3. Patient has a diagnosis of GERD with endoscopy and/or pH-metry test within the past two years demonstrating 1 or more of the following:

   1. Erosive esophagitis (Grade A or greater based on the Los Angeles classification of esophagitis; Appendix 3)
   2. Evidence of pathological acid reflux (pH < 4 for ≥ 4-6% off therapy or ≥ 1-4% on therapy) during a 24-hour time interval of pH testing
4. Patient reports heartburn severity (HS, Item #1 on mRESQ-eD) ≥ 3 (moderate) on at least 2 days and has an average HS of ≥ 2 (mild) during the last 7 days of the Pretreatment Period before Randomization.

Exclusion Criteria:

1. Patient is suspected of having, functional upper gastrointestinal disorders such as functional dyspepsia or functional heartburn diagnosed by the Rome IV criteria; Appendix 4.
2. Patient has endoscopically confirmed eosinophilic esophagitis (EE).

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Oral Fosamprenavir-Sodium Alginate (FOS-SA); Eight weeks of: 1400 mg FOS-SA BID: 15 ml oral solution containing 1400 mg fosamprenavir calcium and 24.5 mg sodium alginate administered BID, at least 1 hour before or 2 hours after the morning and evening meals, approximately 12 hours apart	Drug: Fosamprenavir Calcium & Sodium Alginate; 1400 mg FOS-SA BID: 15 ml oral solution containing 1400 mg fosamprenavir calcium and 24.5 mg sodium alginate administered BID
Placebo Comparator: Oral Placebo; Eight weeks of: 15 ml oral solution containing 1,399 mg microcrystalline cellulose and 24.5 mg sodium alginate administered BID at least 1 hour before or 2 hours after the morning and evening meals, approximately 12 hours apart	Other: Placebo; 15 ml oral solution containing 1,399 mg microcrystalline cellulose and 24.5 mg sodium alginate; Other Names: Microcrystalline cellulose; Sodium Alginate

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Weekly Heartburn Severity Score	Based on questions 1 and 2 of mRESQ-eD. The percent change from baseline (i.e., Pretreatment) in heartburn severity as indicated by Weekly Heartburn Severity Score (WHSS) at Week 8 (end of Treatment Period). Weekly scoring averaged. [Minimum Value: 0, Maximum Value: 500, higher score= worse outcome]	Ten days of pre-screening and dailyfor 8 weeks.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Weekly Regurgitation Frequency Score	Based on questions 7 and 7 of mRESQ-eD. The percent change from baseline (i.e., Pretreatment) in regurgitation frequency as indicated by Weekly Regurgitation Frequency Score (WRFS) at Week 8. Weekly scoring averaged. [Minimum Value: 0, Maximum Value: 400, higher score= worse outcome]	Ten days of pre-screening and daily for 8 weeks.
Daily modified Reflux Symptom Questionnaire Electronic Diary (mRESQ-eD)	The percent change from baseline (i.e., Pretreatment) in symptoms of persistent GERD as indicated by mRESQ-eD weekly total GERD score (WTGS) at Week 8. Weekly scoring averaged. [Minimum Value: 0, Maximum Value: 1850, higher score= worse outcome]	Ten days of pre-screening and daily for 8 weeks.

Collaborators and Investigators

• Sponsor: Medical College of Wisconsin
• Investigators: Principal Investigator: Nikki Johnston, PhD., Medical College of Wisconsin

Study record dates

Study Major Dates

• Study Start (Estimated): March 1, 2026
• Primary Completion (Estimated): February 28, 2028
• Study Completion (Estimated): June 1, 2028

Study Registration Dates

• First Submitted: November 19, 2024
• First Submitted That Met QC Criteria: November 20, 2024
• First Posted (Actual): November 25, 2024

Study Record Updates

• Last Update Posted (Estimated): October 6, 2025
• Last Update Submitted That Met QC Criteria: October 2, 2025
• Last Verified: October 1, 2025

More Information

Terms related to this study

• Keywords: Fosamprenavir; Sodium Alginate; PPI-refractory GERD; Proton pump inhibitor refractory gastroesophageal reflux disease; Fosamprenavir-Sodium Alginate; FOS-SA
• Additional Relevant MeSH Terms: Digestive System Diseases; Gastrointestinal Diseases; Esophageal Diseases; Esophageal Motility Disorders; Deglutition Disorders; Gastroesophageal Reflux; Carbohydrates; Polysaccharides; microcrystalline cellulose; fosamprenavir; Alginates
• Other Study ID Numbers: PRO000000000

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No