Please select the eligibility criteria that correspond to the clinical trial below.
Title: Study PXN110448: A Dose-response Study of XP13512, Compared With Concurrent Placebo Control and LYRICA(Pregabalin), in Subjects With Neuropathic Pain Associated Withdiabetic Peripheral Neuropathy (DPN)
Brief Summary: The purpose of this study is to determine whether gabapentin enacarbil (XP13512/GSK1838262), hereafter referred to as GEn is effective in the treatment of neuropathic pain associated with diabetic peripheral neuropathy(DPN)


Options:
A: Inclusion Criteria:

* Must be resident of the county of San Diego, California
* Ages 21-70 inclusive
* Low back pain (T-6 or below, secondary to degenerative disk or degenerative joint disease) present "on a daily basis" for the previous 6 months or longer, of at least "moderate" intensity determined by Descriptor Differential Scale (DDS) \> 7
* English-speaking, literate, able to understand the study and communicate with the study team
* Presently not a candidate for back surgery (one prior back surgery permitted if it was \> 5 years ago and resulted in complete relief)
* Discontinued muscle relaxants, anticonvulsants, antidepressants, and opioids at least two weeks before screening and agree to discontinue throughout study (can remain on stable dose of NSAIDs)
* If female, not pregnant or lactating; agrees to use reliable contraception throughout the study, and has negative pregnancy test at screening
* Gives informed consent.

Exclusion Criteria:

* A major coexisting medical illness (e.g., diabetes, renal or hepatic disease, chronic obstructive pulmonary disease, cancer, or class III or IV organic heart disease) that might increase risks of gabapentin, or major surgical or non-surgical intervention for any disorder within the past 12 months, since rehabilitation from treatment may confound study outcomes
* Significant coexisting orthopedic or pain problems; sciatica (pain, weakness, or dysesthesia solely in distribution of a lumbar spinal nerve, with or without reflex change) or back pain due to other disorders (e.g., fibromyalgia, vertebral fracture, osteomyelitis, metastatic cancer, rheumatoid arthritis; spinal stenosis)
* Diagnostic and Statistical Manual (DSM)-IV diagnosis of alcohol or other substance abuse or dependence (within the previous 12 months or positive urine toxicology at screening), current major depression or dysthymia; or lifetime bipolar disorder (I or II) (excluded because gabapentin is antidepressive and antimanic); or major anxiety disorder (e.g., panic disorder; or psychosis; or lifetime presence of cognitive impairment disorder (e.g. dementia)
* History of multiple adverse drug reactions or known allergy to gabapentin
* Use of psychotropics (e.g., antidepressants, anxiolytics), which would need to be continued during the study, or other drugs or agents (i.e., herbal preparations) which might interact with the study drug
* Prior treatment with the study drug
* Use of systemic corticosteroids or corticosteroid injections within three months of screening; or concurrent behavioral therapies, chiropractic treatment, or transcutaneous electrical nerve stimulation unit
* Renal impairment (creatinine \> 1.8 mg/dL)
* Hepatic impairment (bilirubin \> 1.5 X upper normal limit, or aspartate aminotransferase (AST) or alanine transaminase (ALT) \> 2 X upper normal limit)
* Hematologic abnormality (hemoglobin \< 9.4 gm/dL; absolute white blood cell (WBC) count \< 3000/mm3, platelets \< 100,000
* Pregnancy
* Immunosuppression
* Use of experimental drugs or participation in other clinical trials
B: Inclusion criteria:

* 18 years or older
* Female subjects are eligible to enter if of non-childbearing potential or not lactating, has a negative pregnancy test and agrees to use a specified highly effective method for avoiding pregnancy
* Documented medical diagnosis of Type 1 or 2 diabetes including:
* Stable glycemic control for 3 months defined as \<25% change of routine insulin, \<50% change of routine oral anti-diabetic agent dose and HbA1c \< 8%. (HbA1c of 8 to 11% eligible if attempts to improve diabetic control failed)
* DPN defined by:
* Bilateral reduced or absent reflexes at the ankles, or
* Bilateral impaired vibration, pinprick, fine touch or temperature perception in the distal lower extremities And
* Persistent distal burning or dull pain in the feet, or
* Persistent proximal aching pain in the legs, or
* Paroxysmal electric, shooting, stabbing pain, or
* Dysasthesias, or
* Evoked pain And
* history of pain for at least six months and no greater than five years attributed to DPN (refers to duration of pain)
* Baseline 24-hour average daily pain intensity score \>4.0 as measured on an 11 point pain intensity numerical rating scale
* Provides written informed consent in accordance with all applicable regulatory requirements

Exclusion criteria:

* Other chronic pain conditions not associated with DPN. However, the subject will not be excluded if:
* The pain condition is located at a different region of the body, and
* The pain intensity of this condition is not greater than the pain intensity of the DPN, and
* The subject can assess their DPN independently of other pain condition.
* Other causes of neuropathy or lower extremity pain
* Is unable to discontinue prohibited medications or non-drug therapies or procedures throughout the duration of the study
* Hepatic impairment defined as ALT or AST \> 2x upper limit of normal (ULN) or alkaline phosphatase or bilirubin \> 1.5x ULN
* Chronic hepatitis B or C
* Impaired renal function defined as either creatinine clearance \< 60 mL/min or requiring hemodialysis
* Corrected QT (QTc) interval \>450 msec or QTc interval \>480 msec for patients with Bundle Branch Block
* Uncontrolled hypertension at screen (sitting systolic \>160 mmHg and/or sitting diastolic \>90 mmHg
* Current diagnosis of active epilepsy or any active seizure disorder requiring chronic therapy with antiepileptic drug(s)
* Medical condition or disorder that would interfere with the action, absorption, distribution, metabolism, or excretion of GEn or pregabalin, or, in the investigator's judgment:
* Is considered to be clinically significant and could pose a safety concern or,
* Could interfere with the accurate assessment of safety or efficacy, or,
* Could potentially affect a subject's safety or study outcome
* Meets criteria defined by the DSM-IV-TR for a major depressive episode or for active significant psychiatric disorders within last year
* Depression in remission, with or without antidepressant treatment, may participate, unless stable antidepressant regimen is a prohibited medication
* Antidepressant medication may not be changed or discontinued to met entry criteria and must be stable for at least 3 months prior to enrollment
* History of clinically significant drug or alcohol abuse (DSM-IV-TR). Benzodiazepines or atypical benzodiazepines as hypnotic sleep agents permitted
* Currently participating in another clinical study in which the subject is, or will be exposed to an investigational or non-investigational drug or device
* Has participated in a clinical study and was exposed to investigational or non-investigational drug or device:
* Within preceding month for studies unrelated to DPN, or
* Within six months for studies related to DPN
* Treated previously with GEn
* History of allergic or medically significant adverse reaction to investigational products (including gabapentin or pregabalin) or their excipients, acetaminophen or related compounds
C: Inclusion Criteria:

* Lumbosacral radicular pain based on history and physical exam (e.g. pain radiating into one or both lower extremities, sensory loss, muscle weakness, positive straight leg raising test etc.)
* Numerical Rating Scale leg pain score \> 4 (or if 3/10, greater or equal to back pain)
* MRI evidence of spinal pathology consistent with symptoms

Exclusion Criteria:

* Untreated coagulopathy
* Previous spine surgery
* No MRI study
* Leg pain \> 4 years duration Epidural steroid injection within past 3 years Cauda equina syndrome Previous failed trials with gabapentin or pregabalin Allergic reactions to gabapentin or pregabalin Referrals from surgery for diagnostic injections for surgical evaluation Serious medical or psychiatric that condition that might preclude optimal outcome or interfere with participation, such as the need for uninterrupted anticoagulation.

Pregnancy
D: Inclusion Criteria:

* You must have been diagnosed with Diabetic Neuropathic Pain
* Patient has an average daily pain score greater than or equal to 4 on an 11-point Likert scale, and patient or provider feel that a change from the current gabapentin therapy for pain management is warranted
* Patient is currently treated with gabapentin greater than or equal to 900 milligram/day, has been prescribed the current dose for at least 4 weeks, and has been at least 80% compliant with dosing, according to patient report
* Patient must agree not to change dose of gabapentin between Visits 1 and 2
* You must have stable glycemic control

Exclusion Criteria:

* Are judged prior to randomization to be at suicidal risk as defined by a score of 2 or greater on question 9 of the Beck Depression Inventory-II (BDI-II)
* Current diagnosis or history of hemangiosarcoma
* Patients with New York Heart Association Class III or IV symptoms of congestive heart failure
* Patients with uncontrolled narrow-angle glaucoma
* Presence of a current seizure disorder

Answer: B