An open-label, randomized crossover pilot study to evaluate the pharmacokinetics, bioavailability, and bioequivalence following administration of Oxybate formulations in healthy subjects.

KEY-507 oral solutions are new investigational compounds that are being
evaluated for the treatment of narcolepsy. Narcolepsy is a sleeping disorder
that involves excessive daytime sleepiness and, in some people, a sudden loss
of muscle tone usually triggered by strong emotion (cataplexy). One of the
current medications for excessive daytime sleepiness and cataplexy in
narcolepsy is Xyrem® (sodium oxybate, also known as the sodium salt of
gamma-hydroxybutyric acid [GHB]). This is an oral solution that contains a high
amount of sodium at the highest approved dose. Sodium oxybate/GHB is a
substance that has depressant or sedating effects in people.
KEY-507 are 4 new oral solutions that contain the same active substance as
Xyrem, but reduce the daily intake of sodium. This is the first time that
KEY-507 oral solutions are being given to humans.

During the study, the 4 KEY-507 oral solutions (KEY-507-A, KEY-507-G,
KEY-507-C, and KEY 507-D) will be investigated and compared to Xyrem. The
purpose of the study is to investigate how quickly and to what extent KEY-507
oral solutions are absorbed and eliminated from the body (this is called
pharmacokinetics) when compared to Xyrem. This comparison is called the
relative bioavailability. The safety of KEY-507 oral solutions and to what
extent KEY 507 oral solutions are tolerated will also be investigated. In
addition, you will be asked to evaluate the taste of the KEY-507 oral solutions
and Xyrem.

Day 1 is the first day of administration of KEY-507 or Xyrem. The volunteers
are expected at the clinical research center at 14:00 h in the afternoon prior
to the day of first administration of the study compound. They will be required
not to have consumed any food or drinks during the 4 hours prior to arrival in
the clinical research center (with the exception of water).

Each treatment with KEY-507 or Xyrem is separated by a period of 1 day. They
will receive KEY 507 or Xyrem on Days 1, 3, 5, 7 and 9. During the study they
will stay for 11 days (10 nights: from Day -1 to Day 10) in the clinical
research center.

On the final study day (Day 10) they will undergo a post study screening,
during which they will get similar examinations as in the pre-study screening
(please refer to Chapter 10 of the information booklet). If the participation
in the study is ended earlier than Day 10, they will be asked to undergo the
post-study screening to make sure they are healthy when they leave the clinical
research center.

The participation in the entire study, from pre-study screening until the post
study screening, will be maximally 32 days.

Treatment A: 1 x 9 mL KEY-507-A
Treatment B: 1 x 9 mL KEY-507-G
Treatment C: 1 x 9 mL KEY-507-C
Treatment D: 1 x 9 mL KEY-507-D
Treatment E: 1 x 9 mL Xyrem

During the study various examinations are carried out that can be experienced
more or less stressful.
Blood sampling, indwelling canula, heart tracing.