Inclusion Criteria:

- The patient is willing to provide written informed consent to participate in this
study.

- The patient can be either an out-patient or an in-patient.

- The patient has a histologically documented diagnosis of cancer.

- The patient has stable background pain due to cancer.

- The patient experiences up to 4 BTcP episodes per 24 hours.

- As maintenance opioid therapy, the patient is currently taking 1 of the following: at
least 60 mg of oral morphine/day, at least 25 mcg of transdermal fentanyl/hour, at
least 30 mg of oxycodone/day, at least 8 mg of hydromorphone/day, of an equianalgesic
dose of another opioid for a week or longer before administration of the first dose
of study drug.

- Women of childbearing potential, using a medically accepted, highly effective method
of birth control and agree to continued use of this method for the duration of the
study.

- The patient must be willing and able to successfully self-administer the study drug
and to fill in study documents.

Exclusion Criteria:

- The patient is without maintenance opioid therapy.

- The patient has uncontrolled or rapidly escalating pain as determined by the
investigator.

- The patient has known or suspected hypersensitivities, allergies, or other
contraindications to the active drug or to any of the excipients of the study drug.

- The patient has respiratory depression or chronic obstructive pulmonary disease, or
any other medical condition predisposing to respiratory depression.

- The patient has medical or psychiatric disease that, in the opinion of the
investigator, would compromise collected data.

- The patient is expected to have surgery during the study.

- The patient is pregnant or lactating.

- The patient has participated in a study involving an investigational drug in the
prior 30 days.

- The patient has received a monoamine oxidase inhibitor (MAOI) within 14 days before
the first treatment with study drug.

- The patient has any other medical condition or is receiving concomitant
medication/therapy (e.g., regional nerve block) that could, in the opinion of the
investigator, compromise the patient's safety or compliance with the study protocol,
or compromise collected data.