This was a Phase 1, single-center, randomized, placebo-controlled, 2-period, ascending single-dose study assessing the PK, safety, and tolerability of single ascending doses of XG005 (Period 1) and the naproxen and pregabalin combination (Period 2), in 5 dose groups each with 10 subjects.

Period 1 was double-blind and randomized 8 subjects (1:1 allocation ratio by gender) to XG005 and 2 subjects (1:1 allocation ratio by gender) to placebo. Subjects were enrolled sequentially into a total of 5 ascending dose levels pending safety review, and PK review where possible, of Period 1 of the prior dose level. Sentinel dose participants (1 for XG005 and 1 for placebo) were included as the first dose administered at each dose level in Period 1.

In Period 2, all subjects in the last three XG005 dose groups received approximate molar equivalents of naproxen and pregabalin corresponding to XG005 doses after a 7-day washout period. Period 2 was open-label with 10 subjects per group.

PK blood samples in each treatment period were collected at 0 (pre-dosing), 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12, 24, 48, and 72 hrs after drug administration.

Inclusion Criteria:

• BMI range of 18-30 kg/m2
• Medically healthy subjects
• Creatinine clearance ≥ 80 mL/min

Exclusion Criteria:

• History or presence of significant diseases
• History or presence of alcoholism or drug abuse
• Consumption of alcohol 48 hours prior each dose
• Hypersensitivity or idiosyncratic reaction to the study drug
• Abnormal diet (for whatever reason) during the 30 days prior to the first dosing;
• Donation (standard donation amount or more) of blood or blood products
• Plasma donation within 7 days prior to the study;
• Participation in another clinical trial within 30 days prior to the first dose;
• Female subjects who are pregnant or lactating;
• Hemoglobin < 120 g/L

Period 1: Participants and investigators were blinded Period 2: Open label