Chronic Pain Master Protocol (CPMP): A Study of LY3556050 in Participants With Chronic Low Back Pain

Inclusion Criteria: * Have a visual analog scale (VAS) pain value ≥40 and \<95 during screening. * Have a history of daily pain for at least 12 weeks based on participant report or medical history. * Have a value of ≤30 on the pain catastrophizing scale. * Have a body mass index \<40 kilograms per meter squared (kg/m²) (inclusive). * Are willing to maintain a consistent regimen of any ongoing nonpharmacologic pain-relieving therapies (for example, physical therapy) and will not start any new nonpharmacologic pain-relieving therapies during study participation. * Are willing to discontinue all medications taken for chronic pain conditions for the duration of the study. * Have a history of low back pain for at least 3 months located between the 12th thoracic vertebra and the lower gluteal folds, with or without radiation. * Have a history of low back pain as classified by the Quebec Task Force Category 1 through 3. * Have stable glycemic control as indicated by a glycated hemoglobin (HbA1c) less than or equal to 10 at time of screening. * Are men, or women able to abide by reproductive and contraceptive requirements. Exclusion Criteria: * Have second or third-degree atrioventricular (AV) heart block or AV dissociation or history of ventricular tachycardia. * Have had a procedure within the past 6 months intended to produce permanent sensory loss in the target area of interest (for example, ablation techniques). * Have surgery planned during the study for any reason, related or not to the disease state under evaluation. * Have, in the judgment of the investigator, an acute, serious, or unstable medical condition or a history or presence of any other medical illness that would preclude study participation. * There is an inability to rule out other causative or confounding sources of pain in the primary condition under study. * Have had cancer within 2 years of baseline, except for cutaneous basal cell or squamous cell carcinoma resolved by excision. * Have a substance use disorder as defined by the Diagnostic and Statistical Manual of Mental Disorders (5th edition; DSM-5; American Psychiatric Association). * Have congenital QT prolongation or QT interval corrected for heart rate using Fridericia's formula (QTcF) interval measurement \>450 milliseconds (msec) for male participants, \>470 msec for female participants, or \>480 msec for participants with bundle branch block. * Have any clinically important abnormality at screening, as determined by investigator, …