The purpose of this study is to determine the safety and efficacy of NI-03.

The primary objective of the Single-Dose Phase is to assess the pharmacokinetics (PK) and safety of single doses of NI-03 when administered at doses of 100 mg, 200 mg or 300 mg to subjects with chronic pancreatitis.

The primary objective of the Double-Blind Phase of the study is to determine the efficacy, PK and safety of three doses of NI-03 (100 mg, 200 mg and 300 mg) as compared to placebo when administered three times daily (TID) for 28 consecutive days in subjects with chronic pancreatitis.

Inclusion Criteria:

To be eligible to participate in this study, subjects must meet all of the following criteria at Screening:

1. Males and females aged 18 to 85 years, inclusive, at the time of consent
2. Ability to communicate effectively with clinic site staff, ability and willingness to comply with the study schedule, restrictions, and requirements
3. Institutional Review Board (IRB)-approved written informed consent
4. Diagnosis of chronic pancreatitis
5. Baseline average daily worst pain score must be a minimum of 4 using the Numeric Rating Scale (NRS) during the 7-day run-in period
6. Patients on a non-opioid analgesic regimen that is expected to remain stable during the study period, or an opioid regimen with a morphine-equivalent dose not more than 100 mg daily.

Exclusion Criteria:

To be eligible to participate in this study, subjects must not meet any of the following criteria:

1. Any other clinically significant medical condition
2. Treatment with any investigational product within 14 days of Day 1 (or 5 drug half-lives if 5 drug half-lives are expected to exceed 14 days) of Day -7
3. Major abdominal surgery within 90 days of Day 1
4. History or presence of clinically significant cardiovascular disease
5. History of any cancer, except non-melanoma skin cancer, within 5 years of study enrollment,
6. History of endoscopic intervention within the previous 3 months or presence of a pancreatic duct stent
7. History of illicit drug abuse (i.e. use of any 'illegal' drugs within 6 months)
8. Active heavy alcohol use (defined as more than 2 alcoholic drinks per day or 14 alcoholic drinks per week)
9. Inadequate venous access
10. Significant blood loss, donation of ≥450 mL of blood, or blood or blood product transfusion within 7 days of Day 1
11. History or presence of hepatitis B (surface antigen positivity), active hepatitis C or human immunodeficiency virus (HIV) antibody
12. Active infection within 30 days of Day 1
13. Pregnant, planning to become pregnant or breast feeding
14. Positive urine or serum pregnancy test result at Screening or on Day 1
15. Active major psychiatric illness requiring a change in treatment within 3 months that would confound pain assessments
16. History of seizures within the last 12 months
17. Current use of anticonvulsants, antipsychotics, systemic steroids and, immunosuppressant therapy. *Use of gabapentin, pregabalin and benzodiazepines as treatment for chronic pancreatitis pain are allowed.
18. Presence of generalized pain syndrome apart from chronic pancreatitis