Inclusion Criteria:

- Has somatic or visceral pain due to solid tumor cancers (adrenal, basal cell, and
breast cancers; transitional cell carcinoma of the bladder or uroepithelium;
cholangiocarcinoma; small intestine/colon/rectal cancers; adenocarcinoma,
esophageal/gastric cancers; hepatocellular, ovarian, pancreatic, and prostate
cancers; bony/soft tissue sarcomas; small cell lung cancer; non small cell lung
cancer; and adenocarcinomas of unknown primary origin).

- Has moderate to severe pain as measured by the Pain Intensity Assessment (categorical
scale), and a pain intensity measurement of greater than or equal to 40 mm by visual
analog scale (VAS) prior to the morning dose of pain medication.

- Stable chronic cancer pain as evidenced by a stable, scheduled opioid regimen over 7
days prior to treatment with study medication and fewer than 3 rescue doses per day
averaged over the 3 days prior to treatment with study medication.

- Currently taking morphine, hydromorphone, oxycodone or an oxycodone/acetaminophen
combination for the treatment of cancer pain.

- Age 18 or older.

- Performance status of 0 to 2 by Eastern Cooperative Oncology Group (ECOG) scale.

- If taking concomitant medication, subject has been on a steady regimen for the past 2
weeks.

- For female subjects: 2 years postmenopausal or currently using effective
contraception, and not lactating; negative urine pregnancy test within 24 hours of
randomization.

- Weight of 40 to 90 kg and body mass index (BMI) of 18 to 32 during a 1-week period
prior to treatment.

- Able to remain at facility allowing completion of pain and safety assessments for at
least 8 hours after receiving study medication.

Exclusion Criteria:

- Has any significant medical disease other than malignancy that, in the Investigator’s
opinion, may interfere with study participation or completion of the study.

- Has a history of chronic analgesic or tranquilizer use (except for the subject’s
current pain medication [morphine, hydromorphone, and oxycodone, or an
oxycodone/acetaminophen combination]) or known substance abuse within 90 days prior
to the screening visit. Other drugs with analgesic properties, including
nonsteroidal anti-inflammatory drugs, corticosteroids, tricyclic antidepressants,
anticonvulsants, antiarrhythmics, bisphosphonates or gabapentinoids will not be
initiated during the study. Patients receiving stable doses of these agents for pain
management or other indications for >1 week prior to the screening visit may continue
treatment with these provided that the dose remains constant during the study.

- Is unwilling to abstain from alcohol from at least 8 hours prior to dosing with study
medication until time of discharge from the study unit.

- Has received or anticipates receiving any vitamin and mineral supplements from 24
hours prior to dosing until time of discharge from the study unit.

- Has received any investigational medication within 30 days prior to administration of
study medication or is scheduled to receive an investigational drug other than study
drug during the course of this study.

- Has clinically significant hypersensitivity to morphine, oxycodone, hydromorphone,
other opioids, nonsteroidal anti-inflammatory drugs (NSAIDs), or acetaminophen.

- Has a laboratory abnormality that, in the opinion of the Investigator, would
contraindicate study participation, including aspartate aminotransferase (AST),
alanine aminotransferase (ALT), or blood urea nitrogen (BUN) levels greater than or
equal to 1.5 times the upper limit of normal (ULN) or creatinine level greater than
ULN at the screening evaluation.