Please select the eligibility criteria that correspond to the clinical trial below.
Title: A Randomized Double-blind, Placebo- and Active-control, Parallel-arm, Phase III Trial With Controlled Adjustment of Dose to Evaluate the Efficacy and Safety of CG5503 Prolonged Release (PR) in Subjects With Moderate to Severe Chronic Pain Due to Osteoarthritis of the Knee.
Brief Summary: The purpose of this study is to evaluate whether tapentadol (CG5503) prolonged-release (PR) tablets at doses of 100-250 mg twice daily provide a better pain relief in patients with moderate to severe chronic pain due to osteoarthritis of the knee than a placebo (a medication without active substance). In addition the tolerability of CG5503 PR will be assessed. One third of the patients will receive CG5503 and one third will receive placebo. For further comparison one third of the patients will receive oxycodone controlled release (CR) at doses of 20-50 mg twice daily which is an active approved pain medication. Please note that tapentadol ER (Extended Release) and tapentadol PR (Prolonged Release) are identical and used interchangeably. This is due to United States of America and European naming conventions.


Options:
A: Inclusion Criteria:

* Patients diagnosed with osteoarthritis of the knee based on the American College of Rheumatology (ACR) criteria and functional capacity class of I- III;
* Patients taking analgesic medications for at least 3 months prior to screening and dissatisfied with their current therapy;
* Patients requiring opioid treatment must be taking daily doses of opioid- based analgesic, equivalent to \<160 mg of oral morphine;
* Baseline score of \>=5 on an 11-point numeric rating scale, calculated as the average pain intensity during the last 3 days prior to randomization.

Exclusion Criteria:

* History of alcohol and/or drug abuse in Investigator's judgment;
* Chronic hepatitis B or C, or HIV, presence of active hepatitis B or C within the past 3 months;
* Life-long history of seizure disorder or epilepsy;
* History of malignancy within past 2 years, with exception of basal cell carcinoma that has been successfully treated;
* Uncontrolled hypertension;
* Patients with severely impaired renal function;
* Patients with moderate to severely impaired hepatic function or with laboratory values reflecting inadequate hepatic function,
* Treatment with neuroleptics, monoamine oxidase inhibitors, serotonin norepinephrine reuptake inhibitors (SNRI), tricyclic antidepressants, anticonvulsants, or anti-parkinsonian drugs, treatment with any other analgesic therapy than investigational medication or rescue medication during the trial.
B: Inclusion Criteria:

* Patients diagnosed with osteoarthritis of the knee based on the American College of Rheumatology (ACR) criteria and functional capacity class of I-III
* patients taking analgesic medications for at least 3 months prior to screening and/or dissatisfied with their current therapy
* Patients requiring opioid treatment must be taking daily doses of opioid-based analgesic, equivalent to \<160 mg of oral morphine
* baseline score of greater than or equal to 5 on an 11-point numerical rating scale, calculated as the average pain intensity during the last 3 days prior to randomization.

Exclusion Criteria:

* History of alcohol and/or drug abuse in Investigator's judgement
* history of significant liver insufficiency
* chronic hepatitis B or C, or HIV, presence of active hepatitis B or C within the past 3 months
* life-long history of seizure disorder or epilepsy
* history of malignancy within past 2 years, with exception of basal cell carcinoma that has been successfully treated
* uncontrolled hypertension
* patients with severely impaired renal function
* patients with moderate to severly impaired hepatic function or with laboratory values reflecting inadequate hepatic function
C: Inclusion Criteria:

* Clinical diagnosis of knee or hip osteoarthritis with history of pain at the reference joint for at least 3 months or clinical diagnosis of low back pain of benign origin for at least 3 months
* Must be dissatisfied with their current analgesic therapy (e.g. Non-steroidal anti-inflammatory drugs NSAIDS, COX-2 inhibitors, opioids, paracetamol/acetaminophen
* Have a pain intensity \>4 on Numerical Rating Scale

Exclusion Criteria:

* Life-long history of seizure disorder or epilepsy
* Any of the following within one year: mild/moderate traumatic brain injury, stroke, transient ischemic attack, and brain neoplasm
* Severe traumatic brain injury within 15 years (consisting of more than one of the following: brain contusion (injuries resulting in hemorrhage), intracranial hematoma, unconsciousness or post traumatic amnesia lasting for more than 24 hours) or residual sequelae suggesting transient changes in consciousness
* History of malignancy within past 2 years, with exception of a successfully treated basal cell carcinoma
* Presence of significant pain associated with conditions other than osteoarthritis or low back pain that could confound the assessment or self-evaluation of pain
D: Inclusion Criteria:

* Participants must have signed an Informed Consent Form indicating that they understand the purpose of and procedures required for the trial and are willing to participate in it.
* Participants are men or non-pregnant, non-lactating women. Sexually active women must be postmenopausal, surgically sterile, or practicing an effective method of birth control (e.g., prescription oral contraceptives, contraceptive injections, intrauterine device, double barrier method, contraceptive patch, male partner sterilization) before entry and throughout the trial. Women of childbearing potential must have a negative pregnancy test at screening.
* Participants must be appropriately communicative to verbalize and to differentiate with regard to location and intensity of the pain.
* Participants must be at least 18 years of age.
* Participants must have a diagnosis of chronic low back pain; chronic pain defined as pain lasting for at least 3 months
* If the Participant has radicular pain, this must have been present for at least 3 months and stable for the 4 weeks before enrollment.
* Participant's pain must require a strong analgesic (defined as WHO Step III) as judged by the Investigator.
* Participants must be taking a WHO Step III analgesic on a daily basis for at least 3 months prior to the Screening Visit.
* Participants must have responded to the WHO Step III analgesic, i.e., participants must have a confirmed average pain intensity score (NRS 3) of ≤5 points during the last 3 days prior to the Screening Visit.
* Participants must report opioid-related side effects as the reason to change their analgesic.
* Participants must report a rate of satisfaction with their previous analgesic regimen not exceeding "fair" on a subject satisfaction with treatment scale (5-point VRS).

Exclusion Criteria:

* Presence of a clinically significant disease or laboratory findings that in the Investigator's opinion may affect efficacy or safety assessments.
* Presence of active systemic or local infection that may, in the opinion of the Investigator, affect the efficacy, quality of life/function or safety assessments.
* History of alcohol or drug abuse, or suspicion of in Investigator's judgement.
* Presence of concomitant autoimmune inflammatory conditions.
* Known history of or laboratory values reflecting severe renal impairment.
* Known history of moderately or severely impaired hepatic function.
* History of or active hepatitis B or C within the past 3 months or history of HIV infection.
* History of seizure disorder or epilepsy.
* Any of the following within 1 year: mild/moderate traumatic brain injury, stroke, transient ischemic attack, or brain neoplasm. Severe traumatic brain injury within 15 years (consisting of 1 or more of the following: brain contusion, intracranial hematoma, either unconsciousness or post traumatic amnesia lasting more than 24 h) or residual sequelae suggesting transient changes in consciousness.
* Pregnant or breast-feeding.
* History of allergy to, or hypersensitivity to tapentadol hydrochloride or its excipients, or contraindications related to tapentadol hydrochloride including:
* Subjects with acute or severe bronchial asthma or hypercapnia.
* Subjects who have or are suspected of having paralytic ileus.
* Employees of the Investigator or trial site, with direct involvement in this trial or other trials under the direction of the Investigator or trial site, as well as family members of employees of the Investigator.
* Participation in another trial concurrently or within 4 weeks prior to the Screening Visit.
* Known to or suspected of not being able to comply with the protocol and the use of the investigational medicinal product.
* Use of monoamine oxidase inhibitors within 14 days before the Screening Visit.
* Non-stable dosing of selective serotonin reuptake inhibitors within 30 days before the Screening Visit (the doses must remain stable during the trial).
* Presence of concomitant painful condition other than low back pain that could confound the subject's trial assessments or self evaluation of pain, e.g., anatomical deformities, significant skin conditions such as abscess or syndromes with widespread pain such as fibromyalgia.
* Any painful procedures during the trial (e.g., major surgery) that may, in the opinion of the Investigator, affect the efficacy or safety assessments.
* Pending litigation due to chronic pain or disability.

Answer: A