A single-center, randomized, investigator/subject-blind, adaptive single-ascending dose (Part 1) and multiple-ascending dose (Part 2), placebo-controlled, parallel study to investigate the safety, tolerability, pharmacokinetics and pharmacodynamics of RO6889450 following oral administration in healthy subjects.

RO6889450 is a new investigational compound that may eventually be used for the
treatment schizophrenia and bipolar disorders.

In Part 1, a single dose will be administered of RO6889450 or placebo (same
formulation but then without the active ingredient RO6889450). The purpose of
Part 1 is to investigate how safe RO6889450 is and how well RO6889450 is
tolerated. Part 1 will also investigate how quickly and to what extent
RO6889450 is absorbed into, distributed in, and eliminated from the body (this
is called pharmacokinetics). In addition, the effect of RO6889450 on the body
using several tests (described later on in this document) will be investigated
(this is called pharmacodynamics).

In Part 2, multiple doses will be administered of RO6889450 or placebo (same
formulation but then without the active ingredient RO6889450). The purpose of
Part 2 is to investigate how safe RO6889450 is and how well RO6889450 is
tolerated. Part 2 will also investigate how quickly and to what extent
RO6889450 is absorbed into, distributed in, and eliminated from the body (this
is called pharmacokinetics). In addition, the effect of RO6889450 on the body
using several tests (described later on in this document) will be investigated
(this is called pharmacodynamics).

Part 1:
The actual study will consist of 1 period during which the volunteers will stay
in the clinical research center in Groningen for 6 days (5 nights): from the
afternoon of Day -2 (2 days before administration of the study compound) to the
morning of Day 4. This will be followed by 3 days (Days 6, 7 and 8) during
which they will visit the clinical research center in Groningen for a short
visit.

Part 2:
The actual study will consist of 1 period during which the volunteers will stay
in the clinical research center in Groningen for 20 days (19 nights): from the
afternoon of Day -3 (3 days before administration of the study compound) to the
morning of Day 17. This will be followed by 3 days (Days 19, 20 and 21) during
which they will visit the clinical research center in Groningen for a short
visit.

Part 1:
Group Day Treatment
How often
1 1 5 milligrams RO6889450 or placebo Once
2 1 15 milligrams RO6889450 or placebo Once
3 1 50 milligrams RO6889450 or placebo Once
4 1 100 milligrams RO6889450 or placebo Once
5 1 200 milligrams RO6889450 or placebo Once
6 1 300 milligrams RO6889450 or placebo Once
7 1 450 milligrams RO6889450 or placebo Once

Part 2:
Group Day Treatment
How often
1 1 to 14 X* milligrams RO6889450 or placebo Once daily
2 1 to 14 X* milligrams RO6889450 or placebo Once daily
3 1 to 14 X* milligrams RO6889450 or placebo Once daily
4 1 to 14 X* milligrams RO6889450 or placebo Once daily
5 1 to 14 X* milligrams RO6889450 or placebo Once daily
* The dose levels are not known yet and will be decided later based on
information from Part 1 of the study

Pain, minor bleeding, bruising, possibly an infection.