Inclusion Criteria:

- Each patient must have chronic severe pain of malignant or nonmalignant etiology with
inadequate pain relief from or intolerance to conventional therapy.

- Each patient must have a predicted life expectancy of greater than or equal to 6
weeks relative to baseline.

- Each patient must be able to respond to the Visual Analog Scale of Pain Intensity
(VASPI).

- Each patient must have an implanted programmable SynchroMed infusion device or a
CADD-Micro external programmable infusion device and spinal catheter (hereafter "IT
pump and spinal catheter") prior to enrollment into this trial. (If a patient has an
external pump, the Investigator must ensure that the patient is at a low risk for
infection and that the patient is capable of maintaining good personal hygiene. The
Investigator must have demonstrated the ability to successfully manage patients with
external pumps prior to enrolling a patient in this trial.)

- Each patient must be at least 18 years of age.

- Each patient must be competent to give written informed consent and has given written
informed consent prior to performance of any study-related procedures. Reasonable
accommodation of visually impaired patients will be allowed.

- Each patient is willing and able to comply with the protocol requirements.

- Each female patient of childbearing potential must agree to use adequate
contraceptive methods while on PRIALT as determined by the Investigator.

Exclusion Criteria:

- Presence of pregnancy or lactation.

- Participation in another investigational drug or device trial within the preceding 30
days.

- Presence of known hypersensitivity to PRIALT or any of its components.

- Presence of any contraindication to continued IT therapy (for example, infection at
the pump or catheter externalization site, uncontrolled bleeding diathesis, spinal
canal obstruction that impairs cerebrospinal fluid [CSF] circulation, or patient and
caregiver inability to manage and protect the IT pump and spinal catheter system and
return for clinic follow up visits).

- Presence of any condition (for example, psychosis, severe depression or suicidal
ideation, homicidality, somatization disorder, active substance abuse, cognitive
deficits, dementia or other serious medical or psychiatric condition) that in the
Investigator's opinion precludes the patient's ability to participate in this study.