The CALIBER Study Randomized Controlled Trial of LINX Versus Double-Dose Proton Pump Inhibitor Therapy for Reflux Disease

Prospective, multicenter, 2:1 randomized, cross-over, two arms

- Control arm: Double-dose PPI [Omeprazole 20 mg BID (twice a day)]

- Treatment arm: LINX Reflux Management System Up to 20 study centers throughout the U.S.
will participate. Approximately150 patients will be enrolled into the study. Subjects
will be randomized 2:1 into the double-dose PPIs arm (100 subjects) and the LINX arm (50
subjects).

Key Inclusion Criteria:

1. Patient seeks consultation for lack of satisfactory symptom response to once daily
PPIs.

2. Age≥ 21 years old.

3. Abnormal distal esophageal pH determined by total % time pH <4 or DeMeester Score.
Testing to be completed off GERD medications for at least 7 days, with the exception
of antacids, which may be taken up until the morning of assessment.

4. Suitable surgical candidate (i.e. is able to undergo general anesthesia and
laparoscopic surgery).

5. Patient has provided written informed consent for participation in the randomized
study.

Key Exclusion Criteria:

1. Currently taking double-dose PPIs (twice daily dosing).

2. Hiatal hernia >3cm as determined by endoscopy.

3. Distal esophageal motility (average of sensors 3 and 4) is less than 35 mmHg
peristaltic amplitude on wet swallows or <70% (propulsive) peristaltic sequences.

4. Esophagitis Grade C or D (Los Angeles classification).

5. Body mass index >35.

6. Diagnosed with an esophageal motility disorder LES.

7. Esophageal stricture or gross esophageal anatomic abnormalities

8. History of/or known Barrett's esophagus.

9. Suspected or known allergies to titanium, stainless steel, nickel or ferrous
materials.