This randomized, double-blind, placebo-controlled, parallel group study will evaluate the pharmacodynamics and pharmacokinetics of RO5508887 in healthy volunteers.

Subjects will be randomized in cohorts to receive single oral doses of either RO5508887 or placebo. In-unit period is 6 days.

Inclusion Criteria:

• Healthy male subjects, 18 to 65 years of age, inclusive. Healthy status is 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) 18 to 30 kg/m2 inclusive
• Must agree to use a barrier method of contraception during the treatment period and for at least 30 days after the last dose of study drug
• Donation of blood over 500 mL within 6 weeks before drug administration

Exclusion Criteria:

• Concomitant disease or condition or treatment that could interfere with the conduct of the study or would, in the opinion of the investigator, pose an unacceptable risk to the subject in this study
• Allergy to lidocaine
• Suspicion of regular consumption of drug of abuse
• Regular smoker (> 5 cigarettes, > 1 pipeful or > 1 cigar per day)
• Positive for hepatitis B, hepatitis C or HIV 1 or 2 infection
• Participation in an investigational drug or device study (last administration of study drug or installation of device) within 6 weeks before RO5508887 administration and within 5 mean half-lives of receiving previous investigational drug before RO5508887 administration. In addition, subject cannot participate unless completely recovered from previous invasive or study procedure
• Donation of blood over 500 mL within 6 weeks before drug administration