A Study of the Effect of Multiple Doses of Rifampin on the Single Dose Pharmacokinetics of RO5424802

Inclusion Criteria:

- Healthy male and female volunteers, 18 to 55 years of age inclusive. Healthy status
will be defined by absence of evidence of any active or chronic disease following a
detailed medical and surgical history, and a complete physical examination

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

- Nonsmoking subjects and former smoking subjects (who have not smoked for the past six
months before first dosing)

- Female subjects must be surgically sterile or postmenopausal for the past year

- Male subjects and their partners of childbearing potential must be willing to use two
effective methods of contraception, one of which must be a barrier method (e.g.,
condom) during the study and for 90 days after the last drug administration

Exclusion Criteria:

- Women of childbearing potential, pregnant or lactating women, or males with female
partners who are pregnant or lactating

- Positive urine 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

- History (within three 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 entry in the clinical site center
and throughout the entire study (including the washout period) until discharge

- Positive for hepatitis B, hepatitis C, or HIV infection

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

- Any clinically significant concomitant disease or condition that could interfere
with, or for which the treatment of might interfere with, the conduct of the study,
absorption, distribution, metabolism or excretion of study medication, or that would,
in the opinion of the PI, pose an unacceptable risk to the subject in this study

- History of hypersensitivity to any of the additives in the RO5424802 formulation
(lactose monohydrate, microcrystalline cellulose, sodium starch glycolate,
hydroxypropyl cellulose, sodium lauryl sulphate, magnesium stearate)

- Any history of hypersensitivity to or contraindication to the use of rifampin or
other rifamycins or history of severe drug-related allergic reactions or hepatoxicity