Inclusion Criteria:

- Willing and able to give informed consent.

- Male or female, age 18 years or above.

- Diagnosed with cancer of any type, which is considered to be terminal.

- Diagnosed with cancer-related pain which is not wholly alleviated with their current
strong opioid treatment and whose level of pain measured on a NRS is ³four on at
least one occasion per day, during the two day run-in period, leading up to visit 1.

- On strong opioid maintenance therapy for at least seven days prior to the screening
visit.

- Willing to abstain from any use of cannabis during the study, other than the study
medication.

- No cannabinoids use (cannabis, Marinol® or Nabilone) for at least seven days before
Visit 1 and willing to abstain from any use of cannabis during the study.

- Clinically acceptable blood results at the screening visit.

- Able (in the investigators opinion) and willing to undertake and comply with all
study requirements.

- Willing to allow their own general practitioner, and consultant if appropriate, to be
informed of study participation.

- Willing for the Home Office to be notified of his or her participation in the study
(applicable to the UK centres only).

Exclusion Criteria:

- Know history of substance misuse.

- Known or suspected to have had an adverse reaction to cannabinoids causing psychosis
or other severe psychiatric illness.

- Received any epidural analgesia within 48 hours prior to study entry.

- Either received, within two weeks of study entry, or due to receive chemotherapy or
radiotherapy during the study.

- Unable to give informed consent.

- History of any type of schizophrenia, any other psychotic illness, a serious
personality disorder, or other significant psychiatric illness other than depression
associated with their chronic pain and/or in response to the underlying condition.

- Currently taking levodopa (Sinemet®, Sinemet plus®, Levodopa®, L-dopa®, Madopar®,
Benserazide®).

- Had a serious cardiovascular disorder, including angina, uncontrolled hypertension,
or an uncontrolled symptomatic cardiac arrhythmia.

- Significant renal or hepatic impairment, who in the opinion of the investigator, were
unsuitable for treatment with study medication.

- History of epilepsy.

- Had oral cavity cancers or whose previous treatments had included radiotherapy to the
floor of the mouth.

- Female subjects who were pregnant or lactating or of child-bearing potential and were
inadequately protected against conception during the study and for three months
thereafter.

- Male subjects who were sexually active and who were not using adequate forms of
contraception during the study and for three months thereafter.

- Subjects who had participated in a clinical research study in the past four weeks,
prior to study entry.

- Planned travel outside the UK during the study (applicable to the UK centres only).

- Subjects who, in the opinion of the investigator, were unsuitable to participate in
the study for any other reason, not mentioned in the entry criteria.