The objective of this study is to evaluate the safety of up to 12 months (52 weeks) of once daily oral administration of BLI5100 in patients with non-erosive reflux disease (NERD) or healed erosive esophagitis (EE).

Inclusion Criteria:

1. Have completed the BLI5100-301 or BLI5100-302 study with no serious AE (SAE) related to study drug and no major Protocol Deviations;
2. Able to understand and comply with the protocol requirements;
3. Willing and able to provide written informed consent at Screening;
4. Is a female of non-childbearing potential, or If a female of childbearing potential, agrees to use an acceptable form of birth control and avoid egg donation from the Screening Visit until 6 months after the last dose of study drug;
5. If a male, agrees to use an acceptable form of birth control from the Screening Visit until 3 months after the last dose of study drug;
6. If a male, agrees to abstain from sperm donation through 3 months after administration of the last dose of study drug;
7. Have documented healed EE (BLI5100-301 study patients only).

Exclusion Criteria:

1. History of alcoholism, or substance abuse/addiction in the year before enrollment in the BLI5100-301 and BLI5100-302 studies;

   • Note: Patients on prescribed opioids are eligible to participate if they have been on a stable dose for the duration of the BLI5100-301 and BLI5100-302 studies.
   • Note: Retesting of a positive urine drug screen requires Medical Monitor approval. Positive urine drug screen for all drugs will require verification of prescription for the positive tested substance.

2. A diagnosis of manic-depression, anxiety disorder, panic disorder, somatoform disorder, personality disorder, or other psychological disorder is exclusionary, unless the patient is asymptomatic and well-controlled. Stable treatment, including non-medical therapy, is preferred, but minor adjustments can be made and should be consulted with the Medical Monitor;

3. Current use of antipsychotics, antidepressants, anxiolytics, or prescription sleeping medications, with the exception of a stable dose for the duration of the BLI5100-301 and BLI5100-302 studies;

4. Requirement of persistent (>3 times per week for >30 days) use of non-steroidal anti-inflammatory drugs (NSAIDs) during the course of the study;

   o Note: Low-dose (≤100 mg/day) aspirin is allowed provided that it has been used for prophylaxis prior to study participation.

5. If a female, is pregnant, breastfeeding, or planning to become pregnant during the study or within 6 months after the last dose of study drug;

6. Abnormal laboratory results with clinical relevance at Screening as follows:

   • Aspartate aminotransferase (AST), alanine aminotransferase (ALT), or alkaline phosphatase level of ≥2 × upper limit of normal (ULN);
   • Total bilirubin level of ≥2 × ULN, unless Gilbert's syndrome is confirmed when direct bilirubin is ≤0.3 mg/dL;
   • Estimated glomerular filtration rate <30 mL/min.
   • Note: A lab value obtained during the Screening period may be retested once with Medical Monitor approval.

7. Abnormal ECG of clinical significance;

8. Involvement in another clinical study (other than BLI5100-301 and BLI5100-302 studies) within 4 weeks of initiation of study drug;

9. Any other clinically relevant condition that would confound study endpoints or adversely affect patient compliance with the study procedures in the medical judgment of the Investigator or Medical Monitor based on previous medical history or findings on Screening assessments.