A Study Investigating the Effect of Food and Esomeprazole on the Single Oral Dose Pharmacokinetics of RO5424802 in Healthy Volunteers.

Inclusion Criteria:

- 18 to 55 years of age, inclusive.

- Body mass index (BMI) between 18 to 32 kg/m2 inclusive.

- Healthy male and female volunteers. Healthy status will be defined by absence of
evidence of any active or chronic disease following a detailed medical and surgical
history, a complete physical examination including vital signs, 12-lead
electrocardiogram (ECG), hematology, blood chemistry, serology and urinalysis.

- Female subjects must be surgically sterile or post-menopausal for the past year
confirmed by a blood follicle stimulating hormone (FSH) test for females without
hormone replacement therapy (HRT).

- Male subjects must be willing to use effective contraception, as defined by the
protocol, throughout the study and for 3 months after last drug administration.

- Willing to abstain from xanthine-containing beverages or food (coffee, tea, cola,
chocolate, and "energy drinks") use from 72 hours prior to admission to the study
clinic until discharge.

- Willing to abstain from consuming grapefruit, pomelo, star fruit, or Seville orange
containing products from 7 days prior to first dose of study medication through
discharge.

- Willing to avoid prolonged sun exposure while taking RO5424802 and through follow-up.
Subjects should also be advised to use a broad spectrum sun screen and lip balm of at
least sun protection factor (SPF) > 30 to help protect against potential sunburn.

- Group 2 participants should be H. Pylori negative via breath test.

Exclusion Criteria:

- Pregnant or breastfeeding women, males with female partners who are pregnant or
breastfeeding, or women of childbearing potential.

- Positive test for drugs of abuse, alcohol or cotinine test at screening or prior to
admission to the study unit.

- Suspicion of regular consumption of drug(s) of abuse including marijuana.

- Current smokers or subjects who have discontinued smoking less than six months prior
to first dosing. Subjects should avoid smoky environments for at least 1 weeks prior
to each cotinine test.

- History (within 3 months of screening) of alcohol consumption exceeding 2 standard
drinks per day on average (1 standard drink = 10 grams of alcohol). Alcohol
consumption will be prohibited 72 hours prior to admission to the study clinic and
throughout the entire study until discharge.

- Participants with any risk factors or family history for QT/QTcF prolongation or ECG
abnormalities or any abnormality in the ECG that, in the opinion of the investigator,
increases the risk of participating in the study.

- Confirmed systolic blood pressure (SBP) greater than 140 mmHG or less than 90 mmHg or
diastolic blood pressure (DBP) greater than 90 mmHg or less than 45 mmHg at
screening, admission to the study center or prior to dosing.

- Notable resting bradychardia (mean pulse rate < 45 bpm) or tachycardia (mean pulse
rate > 90 bpm).

- Use of any medications (prescription or over-the-counter) within 2 weeks or 5
half-lives (whichever is longer) before the first dose of the study medication with
the exception of acetaminophen up to 2 g per day up to 48 hours prior to dosing, not
to exceed 4 g total during the week prior to dosing.

- Use of any herbal supplements or any metabolic inducers within 4 weeks or 5
half-lives (whichever is longer) before the first dose of study medication, including
but not limited to the following drugs: rifampin, rifabutin, glucocorticoids,
carbamazepine, phenytoin and phenobarbital.

- Strenuous activity, sunbathing or contact sports are not allowed from 4 days prior to
entry into the clinical site and for the duration of the study until follow-up.

- Participation in an investigational drug or device study within 45 days or 5
half-lives (whichever is longer) or 6 months for biologic therapies prior to first
dosing.

- Donation of blood over 450 mL within 45 days prior to screening.

- Regular use of antacids, H-2 receptor blockers, PPIs or any medications which may
alter the normal gastric environment and/or motility. No use of such medications
within 2 weeks prior to first dose.