Abuse Potential of HORIZANT With and Without Oxycodone in Healthy, Nondependent Recreational Opioid Users

Inclusion Criteria

• Provision of signed and dated informed consent form (ICF),
• Stated willingness to comply with all study procedures and availability for the duration of the study,
• Male or female, between 18 and 55 years of age, inclusive,
• Current nondependent, recreational opioid user who has used opioid drugs for recreational (nontherapeutic) purposes (i.e., for psychoactive effects) at least 5 times in the subject's lifetime and at least once in the last 12 weeks,
• Body mass index (BMI) within 18.0 kg/m2 to 36.0 kg/m2, inclusive,
• If female, meets 1 of the following criteria:
• If of childbearing potential agrees to use 1 of the accepted contraceptive regimens from at least 30 days prior to the first study treatment administration, during the study, and for at least 30 days after the last dose of the study treatment. An acceptable method of contraception includes 1 of the following:
• Abstinence from heterosexual intercourse,
• Hormonal contraceptives (birth control pills, injectable/implantable/insertable hormonal birth control products, transdermal patch), or
• Intrauterine device (IUD; with or without hormones). Or
• If of childbearing potential agrees to use a double barrier method (e.g., condom and spermicide) during the study and for at least 30 days after the last dose of study treatment.

Or

• If of non-childbearing potential, defined as surgically sterile (i.e., has undergone complete hysterectomy, bilateral oophorectomy or tubal ligation) or is in a postmenopausal state (i.e., at least 1 year without menses without an alternative medical condition and confirmed follicle stimulating hormone (FSH) ≥ 40 milli-International unit (mIU)/mL prior to the first study treatment administration),
• If male and engaging in sexual activity that has the risk of pregnancy must agree to use a double barrier method (e.g., condom and spermicide) and agree to not donate sperm during the study and for at least 90 days after the last dose of study treatment, a male who has a pregnant partner shall be excluded,
• Healthy, as determined by no clinically significant findings from medical history, physical examination, 12-lead ECG, vital signs or clinical laboratory (including hematology, clinical chemistry, urinalysis, and serology [screening visit only]) at screening visit and admission, in the opinion of an investigator.
• Negative COVID-19 test prior to each admission.

Exclusion Criteria

• History of significant hepatic, renal, cardiovascular, pulmonary, hematologic, neurological, psychiatric, gastrointestinal, endocrine, immunologic, ophthalmologic, or dermatologic disease of any etiology (including infections),
• Presence or history of significant gastrointestinal, liver or kidney disease, or surgery that may affect drug bioavailability with the exception that cholecystectomy is permitted at the discretion of an investigator,
• Presence of any significant respiratory illness or presence or history of chronic respiratory disease (e.g., upper respiratory illness, sleep apnea, emphysema, asthma) at screening (subjects with acute respiratory illness may be rescheduled upon resolution at the discretion of an investigator),
• Personal or family history (first degree relatives) of allergy, hypersensitivity, or drug rash with eosinophilia and systemic symptoms (DRESS) syndrome to gabapentin enacarbil,gabapentin or any drug product including naloxone, opioids (e.g., oxycodone), or related drugs or known excipients of any of the drug products in this study (e.g. lactose),
• History of sensitivity to or poor tolerance of gabapentin enacarbil, gabapentin, pregabalin, naloxone, or oxycodone,
• Female who is lactating at screening,
• Female who is pregnant according to the pregnancy test at screening or prior to the first study treatment administration or planning to become pregnant within 30 days following the last study treatment administration,
• History of substance or alcohol dependence (excluding nicotine