An interventional study to evaluate the effects of dosages on the Pharmacokinetics (PK, the measure of how the human body processes a substance), Tolerability (how well a substance is tolerated by participants), and Safety of different dosages of XG005 when given to healthy participants as either a single oral dose, or as multiple oral doses.

Exclusion Criteria32

• Subjects with unstable or severe illness, including clinically significant malignancy, of hepatic, pulmonary, metabolic, neurologic, cardiovascular, gastrointestinal (e.g., inflammatory bowel disease), hematological, or psychiatric system as indicated on medical history, physical examination, or clinical laboratory, vital signs, and ECGs evaluations, or in the opinion of the Investigator;
• Subjects with reported history of, or current treatment for, gastrointestinal (GI) disease such as diverticulitis, diverticulosis, irritable bowel syndrome, ulcer, inflammatory bowel disease, upper GI disorders (such as UGID, dyspepsia, heartburn), reflux esophagitis (GERD), or history of conditions such as abdominal gunshot wounds;
• Subjects with a clinically significant history of medical condition (in the opinion of the Investigator) associated with GI events such as nausea, vomiting, constipation, and diarrhea;
• Subjects with a history of seizures other than febrile seizures as a child;
• Subjects with any report of acute illness or febrile event that has not resolved within 72 hours of dosing;
• Subjects with history of, or current glucose intolerance; or with history of gestational diabetes;
• Subjects with lifetime history of suicidal behavior or with lifetime history of suicidal ideation as indicated by the C-SSRS (non-suicidal depression will not be exclusionary) (Part 2);
• Subjects with any use of or intent to use any medications, including prescription, over-the-counter, herbal preparations, or vitamin/mineral supplementation, other than study medications, from 7 days prior to first dose through follow-up visit (except for contraceptives as described in inclusion 5c and occasional paracetamol use, up to 1 g/day, prior to Day -1);
• Subjects who have received any medications known to chronically alter drug absorption or elimination processes within 30 days of the first dose administration, or subjects who are taking drugs known to affect liver, renal, or hematological function in the opinion of the Sponsor or Investigator;
• Subjects who have participated (taken investigative drug and/or device) in another clinical trial within 30 days or 5 half-lives, whichever is longer, prior to first dose;
• Subjects with creatinine clearance < 90 mL/min (estimated using the Cockcroft and Gault equation);
• Subjects with any elevation of liver function tests (ALT, AST, GGT, bilirubin, or alkaline phosphatase greater than 1.5 times the upper limit of normal range) at screening; isolated elevation of bilirubin without elevation of direct bilirubin is acceptable;
• Subjects with a creatine kinase (CK) value of greater than 1.5 times the upper limit of normal (not clinically significant [NCS] abnormality is acceptable) at screening that is not explainable by exercise and that does not come back to reference range upon retest;
• Subjects with leucocytes or lymphocytes less than 1.5 times the lower limit of normal, eosinophils above the upper limit of normal or hemoglobin < 12.0 g/dL at screening;
• Subjects with proteinuria (more than trace) at Screening;
• Female subjects with a positive pregnancy test at screening or Day -1, or who are breastfeeding;
• Subjects with positive Hepatitis B surface antigen, (except due to recent Hepatitis B vaccination), HCV, or HIV;
• Male subjects with a resting QTcB or QTcF value < 320 msec or > 450 msec, and female subjects with a resting QTcB or QTcF value < 320 msec or > 470 msec, as measured at the Screening visit;
• Subjects who have a heart rate < 40 or > 100 bpm lying supine for 5 minutes;
• Subjects who have a blood pressure higher than 140/90 mmHg;
• Subjects with a history of donation of blood or blood products (with the exception of plasma as noted below), or significant blood loss (Investigator’s discretion) within 30 days prior to the first study dose;
• Subjects with a plasma donation within 7 days prior to first study dose;
• Subjects who have used more than 2 cigarettes, cigars, and nicotine-containing products per month within 6 months prior to first study dose, or plan to use them through completion of the follow-up visit;
• History of drug or alcohol abuse or dependence based on the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition [DSM-IV] criteria (within the 2 years prior to Screening) as reported by the subject or known to the Investigator;
• Subjects with a positive qualitative drug screen for illegal drugs at screening visit or Day -1;
• Subjects who have not abstained from alcoholic beverages/alcohol-containing products at least 72 hours prior to first dose, or plan to consume them through completion of the follow-up visit;
• Subjects who have not abstained from grapefruit/Seville oranges at least 7 days prior to first dose, or plan to consume them through completion of the follow-up visit;
• Subjects who have not abstained from caffeinated beverages/caffeine-containing products at least 48 hours prior to first study dose;
• Subjects with an abnormal diet including lactose/gluten intolerance or other dietary restrictions (except vegetarian/vegan, religious dietary requirements – e.g. halal), as determined by the Investigator during the 60 days prior to the first study dose;
• Subjects who cannot refrain from strenuous exercise from 72 hours prior to first study dose through completion of the follow-up visit;
• Subjects who are employees of the study unit or their family members, students who are working in the study unit, or family members of the Investigator or Sponsor;
• Hypersensitivity or idiosyncratic reaction to the study drug, Lyrica, Naproxen, related compounds, or aspartame.