A Study to Investigate the Safety, Tolerability, and Pharmacokinetics of TMC647055 in Combination With Ritonavir (Part 1) and the Co-administration of TMC435, TMC647055 and Ritonavir (Part 2) in Healthy Japanese Participants

The purpose of the study is to investigate the safety, tolerability, and pharmacokinetics of TMC647055 in combination with ritonavir (Part 1); potential pharmacokinetic drug-drug interactions between TMC435 and the combination of TMC647055 with ritonavir; and to evaluate the short-term safety and tolerability when TMC435, TMC647055 and Ritonavir are co-administered (Part 2) in healthy Japanese participants.

This is a single-center study which consists of 2 parts, sequentially conducted in 2 separate panels of 24 healthy adult Japanese participants each. Part 1 is a double-blinded (neither physician nor participant knows the treatment that the participant receives), placebo-controlled (placebo is compared with the study medication to test whether the study medication has a real effect in clinical study), randomized (the study medication is assigned by chance) single ascending dose (SAD) part which will consist of a screening phase, a treatment phase, and a follow-up visit. Part 1 will have 3 cohorts (Cohort A, B, and C) with 8 participants each and they will be randomly assigned to receive either a single oral dose of TMC647055 (6 participants) or placebo (2 participants) in combination with RTV. The study duration for each participant will be approximately 5 weeks from screening to follow-up visit as maximum in Part 1. Part 2 is an open-label, randomized, 3-way crossover part which will consist of a screening phase, 3 treatment phases, and a follow-up phase. Each of the 24 participants will receive Treatment A, B, and C in 6 sequences (Treatment ABC, BCA, CAB, ACB, BAC, and CBA) with a washout period of at least 7 days between consecutive treatments. Safety evaluation will include assessment of adverse events, clinical laboratory tests, vital signs, electrocardiogram, and physical examination. The study duration for each participant will be approximately 10 weeks from screening to follow-up visit as maximum.

Eligibility Criteria:
Inclusion Criteria:

* Man or woman of Japanese descent who has resided outside Japan for no more than 5 years and whose parents and grandparents are Japanese as determined by participant's verbal report
* Must have signed an informed consent form
* Women must be of non-child-bearing potential (postmenopausal for at least 2 years, surgically sterile, or otherwise incapable of becoming pregnant)
* Women, except for postmenopausal women, should have a negative serum b-human chorionic gonadotropin pregnancy test at screening
* Men heterosexually active with a woman of childbearing potential must agree to use two effective methods of birth control, and all men must also not donate sperm during the study and for 3 months after receiving the last dose of study medication
* Must have a body mass index between 16.0 and 30.0 kg/m2, inclusive, and body weight not less than 45 kg at screening

Exclusion Criteria:

* History or evidence of current use of alcohol, barbiturate, amphetamine, recreational or narcotic drug use within the past 1 year which in the Investigator's opinion would compromise participant's safety and/or compliance with the study procedures
* Participant's with Hepatitis A, B, or C infection, or human immunodeficiency virus type 1 or 2 (HIV-1 or HIV-2) infection at study screening
* Female participants who are breastfeeding at screening
* History of liver or renal impairment, significant cardiac, vascular, pulmonary, gastrointestinal, endocrine, neurologic, hematologic, rheumatologic, psychiatric, neoplastic, or metabolic disturbances
* History of clinically relevant skin disease or history of allergy to any medication