A RANDOMIZED DOUBLE-BLIND TRIAL, USING A SINGLE-BLIND RUN-IN TO ASSESS WITHDRAWAL SYMPTOMS AFTER PROLONGED TREATMENT WITH CANNABIDIOL (GWP42003-P)

GWP42003-P (cannabidiol; CBD) is a new investigational compound that may
eventually be used for the treatment of epilepsy. It is extracted from cannabis
plants under highly controlled conditions to ensure the product is always the
same. Within the human body there is a biological system named the endogenous
cannabinoid system (ECS). CBD is absorbed and distributed very rapidly to
tissues and a number of the therapeutic actions of CBD are thought to be
produced via the body*s own ECS. In previous GW studies, CBD has not been
associated with potential psychoactive effects that have been documented with
recreational cannabis use.

GWP42003-P is not yet registered as a drug but has been given to humans in both
clinical studies and as part of an approved product in combination with another
drug for the treatment of spasticity in multiple sclerosis in a number of
countries. GWP42003-P has been given to over 200 children and young adults at
doses up to 25 mg/kg/day in the United States by GW Pharmaceuticals Ltd.

The purpose of the study is to investigate to what extent GWP42003-P might lead
to withdrawal effects after several weeks of dosing. Withdrawal effects are the
signs and symptoms that can occur upon the abrupt discontinuation of some
medications or recreational drugs.

It will also be investigated to what extent GWP42003-P has sedative effects and
whether it influences your mood. In addition, the safety and tolerability of
GWP42003-P will be investigated

The study will consist of 2 periods during which you will receive GWP42003-P or
placebo twice daily for a total of 42 days. GWP42003-P and placebo will each be
given as an oral solution. Each dose will be 7.5 mL.

During the study GWP42003-P or placebo will be administered twice daily for a
total of 42 days.

All drugs can cause adverse effects; the extent to which this occurs differs
between individuals.
The following side effects were experienced among a portion of the 213 patients
(mainly children with severe epilepsy) who have taken GWP42003-P oral solution;
however this was not within a formal clinical study (there was no placebo
treatment). All were considered to be caused by the study compound. They have
been categorized by the likelihood of them occurring, and listed in the order
they have most commonly been reported.

Very common side effects which may affect more than one person in every 10 are:
Feeling drunk, sleepy or abnormal, feeling tired, diarrhea and eating less than
usual.

Common side effects which may affect more than one person in every 100 are
(excluding the very common side effects above): Eating more than usual, weight
gain, weight loss, convulsions (documented in children with pre-existing
epilepsy), difficulty walking and amounts of medicines in the body were higher
than usual (increased levels of other medicines).

Some patients have also developed rashes during treatment with GWP42003-P oral
solution.

The following side effects have been seen in 107 patients who have previously
taken other CBD medicines (either CBD botanical drug substance or purified CBD)
within clinical studies. It should be noted that 87 of these patients took a
formulation containing small amounts of other cannabinoids including
tetrahydrocannabinol (THC) and so may have resulted in a higher incidence of
side effects than with the study compound you will be using. They have been
categorized by the likelihood of them occurring, and listed in the order they
have most commonly been reported. The side effects in bold have been seen in 20
patients who have previously taken study medication of purified CBD, all being
classed as common, with the exceptions of headache and diarrhea which were very
common.

Very common side effects which may affect more than one person in every 10 are:
Diarrhea, headache, feeling sick.

Common side effects which may affect more than one person in every 100 are
(excluding the very common side effects above): Mouth problems (including,
pain, discomfort, change in sense of taste or loss of sense of taste, dry
mouth, reduction in or loss of sensation), feeling tired, indigestion,
sickness, eating less than usual, feeling drunk or abnormal, feeling dizzy,
neck pain, belching, urgency to pass motions, increased frequency in passing
water, rashes, change in liver function blood tests or hematology blood tests,
cold symptoms, abdominal pain, constipation, feeling depressed or confused,
abnormal dreams, nose bleed, feeling weak or unwell, flushing, muscle spasms.