An Investigation of the EndoStim® Lower Esophageal Sphincter (LES) Stimulation System for the Treatment of Reflux

The purpose of this investigation is to demonstrate the safety and effectiveness of the
EndoStim® Lower Esophageal Sphincter (LES) Stimulation System in the treatment of subjects
with gastroesophageal reflux disease (GERD). This investigation is a multicenter, randomized,
double-blind, sham-controlled clinical investigation. After the implant procedure, subjects
will be randomized to either the Treatment Group (immediate stimulation) or Control Group
(delayed stimulation) for a 6-month, double-blind phase followed by an additional open-label
treatment phase in which all subjects will receive electrical stimulation therapy for a total
of 12 months. Subjects continue on stimulation treatment and an extended open-label follow-up
phase includes an 18 month post-stimulation phone interview followed by annual visits through
5 years post-stimulation.

Inclusion Criteria:

1. Able and willing to provide written informed consent

2. Able and willing to comply with required study procedures and follow-up schedule

3. 22 - 75 years of age at the time of informed consent

4. Documented symptoms of gastroesophageal reflux disease (GERD) for longer than 6 months
(regurgitation and/or heartburn which is defined as burning epigastric or substernal
pain which responds to acid neutralization or suppression) which requires daily use of
proton pump inhibitors (PPIs) or other anti-reflux drug therapy, who continue to have
symptoms despite maximum medical therapy or are "intolerant" -severe side-effects
(e.g. anaphylaxis or severe allergic reaction, recurrent C. difficile, severe
hypomagnesaemia) to one PPI or mild/moderate side effect (e.g. nausea, vomiting,
diarrhea or abdominal pain) to at least 2 PPIs of different chemical classes.

5. Symptomatic improvement on PPI therapy demonstrated by a composite GERD-health-related
quality of life (HRQL) score of ≥20 off PPI, and a ≥10 point improvement on PPI
compared to the off PPI composite GERD-HRQL score. Patients who meet the definition
above of PPI intolerant are not required to have ≥10 point improvement. The on-PPI
score to satisfy this criterion will be the score from the GERD-HRQL assessment
completed after resuming PPIs following the Baseline visit.

6. Excessive lower esophageal acid exposure during pH monitoring (defined as distal
esophageal pH < 4 for > 6.0% of the monitoring time) performed after at least 5 days
off of PPIs and at least 2 days off of H2 blockers. At least 18 hour of esophageal pH
recording will be considered adequate and inclusion will be based on the day (at least
18 hours of valid data) with the highest acid exposure percentage time.

7. Esophagitis ≤ Grade B (Los Angeles (LA) classification) as measured by upper endoscopy
off PPI and H2 blockers for 10-14 days

8. Esophageal body contraction amplitude > 30 mmHg for > 30% of swallows and > 30%
peristaltic contractions on HRM or ≥ 30% peristaltic contractions with DCI >450.

9. Suitable surgical candidate able to undergo general anesthesia and laparoscopic
surgery

Exclusion Criteria:

1. Previous EndoStim LES System implant and/or implant attempt

2. Previous surgery involving the gastroesophageal junction or the lead implant site,
such as a Nissen fundoplication

3. Previous endoscopic intervention for the treatment of GERD and/or Barrett's esophagus

4. Hiatal hernia larger than 3 cm as determined by endoscopy

5. History of gastroparesis

6. Any non-GERD esophageal motility disorders that in the opinion of investigator
precludes an anti-reflux procedure

7. History of or known esophageal stricture or significant esophageal anatomic
abnormalities (obstructive lesions, etc.)

8. Barrett's esophagus or any grade of dysplasia

9. Documented history of esophagitis Grade C or D (LA Classification)

10. History of suspected or confirmed esophageal or gastric cancer

11. Esophageal or gastric varices

12. Symptoms of dysphagia more than once per week every week within the last 3 months

13. Unable to tolerate withdrawal from H2 Blockers or PPI medications

14. Suspected or known allergies to titanium, platinum, iridium, stainless steel,
silicone, epoxy, or nylon

15. Body mass index (BMI) > 35 kg/m2

16. Any significant multisystem diseases

17. Autoimmune or a connective tissue disorder (scleroderma, dermatomyositis,
Calcinosis-Raynaud's-Esophagus Sclerodactyly Syndrome (CREST), Sjogren's Syndrome,
Sharp's Syndrome, etc.) requiring therapy in the preceding 2 years

18. Type 1 diabetes mellitus or uncontrolled Type 2 diabetes mellitus (T2DM) defined as
HbA1c > 9.5 in the previous 6 months or at screening/baseline

19. Significant cardiac arrhythmia or ectopy or significant cardiovascular disease (i.e.
unstable angina pectoris, hemodynamically significant valvular disease, severe
congestive heart failure), or any cardiac therapeutic intervention within the last 6
months.

20. Significant cerebrovascular event within the last 6 months

21. Existing implanted electrical stimulator (pacemaker, implantable cardioverter
defibrillator, deep brain stimulator (DBS), bone growth or pelvic floor stimulators,
drug pumps, etc.)

22. Female subject of child-bearing potential and is pregnant or nursing, or intends to
become pregnant during the trial period, who is not using a reliable form of birth
control

23. Currently enrolled in other potentially confounding research

24. Active infection as determined by the investigator

25. History of any malignancy, other than basal cell carcinoma, in the last 2 years

26. Life expectancy less than 3 years aa. Diagnosed major psychiatric disorder (bipolar,
schizophrenia, etc.) bb. Any condition that, at the discretion of the investigator or
sponsor, would interfere with accurate interpretation of the study endpoints or
preclude participation in the trial