Inclusion Criteria:

- Subjects must have signed an Informed Consent Form.

- At least 18 years of age.

- Male and non-pregnant, non-lactating female subjects. Sexually active women must be
post menopausal, surgically sterile, or practicing an effective method of birth
control before entry and throughout the trial. Female subjects of child-bearing
potential must have a negative pregnancy test at enrollment.

- Within 24 weeks of either full completion or completion of the Double-blind Treatment
Period (Visit 8) of KF5503/15 trial performed in subjects with moderate to severe
chronic malignant tumor related pain.

- Subject is, in the opinion of the Investigator, expected to continue to have an
overall positive benefit/risk ratio from continuing analgesic treatment within this
trial.

- Subjects must be willing to take tapentadol PR throughout their participation in the
trial.

Exclusion Criteria:

- History of alcohol and/or drug abuse.

- The subject has a clinically significant disease other than cancer that in the
Investigator's opinion may affect the safety of the subject.

- Employees of the Investigator or trial center or family members of the employees or
the Investigator.

- Known to or suspected of not being able to comply with the protocol and the use of
tapentadol PR.

- Concurrent participation in another trial (except for participation in the KF5503/15
trial) or planning to be enrolled in another clinical trial during the course of this
trial.

- Previous participation in another trial between the end of KF5503/15 and enrollment
into the current trial, KF5503/52.

- History of seizure disorder, epilepsy, traumatic brain injury, stroke or transient
ischemic attack.

- Known history and/or presence of cerebral tumors or metastases.

- Rapidly escalating pain or pain uncontrolled by therapy and was previously treated
with maximum (dose level 4) Investigational Medicinal Product dose.

- Subjects taking any prohibited concomitant medications.

- Uncontrolled hypertension.

- Known moderate or severe hepatic impairment.

- Known severe renal impairment.

- Clinically relevant history of hypersensitivity, allergy, or contraindications to
mu-opioid receptor agonists.