A Study of Duloxetine (LY248686) in Participants With Chronic Low Back Pain

The purpose of the study is to assess the efficacy and safety of duloxetine in participants with Chronic Low Back Pain (CLBP).


Eligibility Criteria:
Inclusion Criteria:

* Participants with CLBP present for the preceding 6 months or longer
* Participants used nonsteroidal anti-inflammatory drugs for CLBP for more than 14 days on average per month in the past 3 months and more than 14 days in one month prior to screening
* Participants having a score of ≥4 on Brief Pain Inventory (BPI) average pain score before randomized
* Female participants having child-bearing potential must test negative (-) on a pregnancy test

Exclusion Criteria:

* Participants have received treatment within the last 30 days with a drug that has not received regulatory approval for any indication
* Participants having a history of low back surgery
* Participants having received epidural steroids, facet block, nerve block or other invasive procedures aimed to reduce low back pain within one month prior to screening
* Participants who have any difficulties to fulfill diary appropriately
* Participants having any previous diagnosis of psychosis, bipolar disorder, or schizoaffective disorder
* Participants having major depressive disorder as determined using depression module of the Mini-International Neuropsychiatric Interview
* Participants having primary painful condition due to other than CLBP
* Participants being anticipated by the investigator to require use of nonsteroidal anti-inflammatory drugs and includes acetaminophen, opioid analgesics, or other excluded medication for the duration of the study
* Participants being considered as inappropriate for participation to the study for any medical or other reason as judged by the investigator
* Participants answering "yes" to any of the questions about active suicidal ideation/intent/behaviors occurring within the past month (Columbia Suicide Severity Rating Scale, Suicide Ideation section - Questions 4 and 5; Suicidal Behavior section)
* Participants having a positive urine drug screen for any substances of abuse or excluded medication
* Participants having alanine aminotransferase or aspartate aminotransferase higher than 100 International Units per Liter (IU/L) or total bilirubin higher than 1.6 milligram per deciliter (mg/dL)
* Participants having serum creatinine level higher than 2.0 mg/dL, or had renal transplantation or receiving renal dialysis
* Participants having uncorrected thyroid disease, uncontrolled narrow-angle glaucoma, history of uncontrolled seizures, or uncontrolled or poorly controlled hypertension
* Participants have had previous exposure to duloxetine or completed / withdrawn from any study investigating duloxetine
* Participants having serious or unstable cardiovascular, hepatic, renal, metabolic, respiratory, or hematologic illness, symptomatic peripheral vascular disease, or other medical condition or psychiatric conditions that, in the opinion of investigator, would compromise participation or be likely to lead to hospitalization during the course of the study
* Participants have known hypersensitivity to multiple medications
* Participants having diagnosis seronegative spondyloarthropathy or rheumatoid arthritis
* Participants taking any excluded medications that cannot be discontinued
* Participants treating with a monoamine oxidase inhibitor (MAOI) within 14 days or the potential need to use an MAOI during the study or within 5 days of discontinuation of study drug
* Participants are non-ambulatory or require the use of crutches or a walker
* Participants having a history of substance abuse or dependence within the past year, excluding nicotine and caffeine
* Pregnant participants or participants were breast-feeding, or wished to be pregnant during the clinical trial period
* Participants cannot use appropriate contraceptive method or do not want to use that from screening until one month after the end of administration of the investigational drug