A Phase 1 Study to Assess the Safety,Tolerability, and Pharmacokinetics of GS-6615 in Healthy Subjects

Inclusion Criteria:

- Weight of at least 50 kg with body mass index (BMI) between 18 and 30 kg/m2

- Female subjects must be of non-childbearing potential as defined per the protocol

- Male subjects with female partners of childbearing potential must be using protocol
acceptable methods of contraception

- Willing and able to comply with the requirements of the protocol and directions

- Willing to avoid consumption of grapefruit, grapefruit juice and Seville oranges

- Willing to avoid consumption of nicotine (including nicotine gum) and alcoholic
beverages

Exclusion Criteria:

- Ongoing or history of any medical or surgical condition that, in the judgment of the
Investigator, might jeopardize the subject's safety or interfere with the study
objectives

- History of meningitis or encephalitis, seizures, migraines, tremors, myoclonic jerks,
sleep disorder, anxiety, syncope, head injuries or a family history of seizures

- Any abnormal ECG findings, abnormal laboratory value, or physical examination
findings at Screening judged to be clinically significant

- Any abnormal neurological examination findings at Screening that is judged as
clinically significant

- Hemoglobin < 12 g/dL

- Serology test positive for HIV, or hepatitis B or C

- Positive urine drug test (including cotinine or ethanol)

- Use of systemic prescription medications or over the counter (OTC) medication,
including multivitamins, and dietary and herbal supplement

- Use of any experimental or investigational drug or device within 30 days

- Female subjects who are of childbearing potential, pregnant or lactating

- Donation or loss of blood within 8 weeks and/or donation of plasma within 7 days

- History of drug or alcohol abuse

- Psychosocial or addictive disorders