Chronic Pain Master Protocol (CPMP): A Study of LY3556050 in Participants With Diabetic Peripheral Neuropathic Pain

This study is being done to test the safety and efficacy of the study drug LY3556050 for the treatment of diabetic peripheral neuropathic pain. This trial is part of the chronic pain master protocol (H0P-MC-CPMP) which is a protocol to accelerate the development of new treatments for chronic pain.


Eligibility Criteria:
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 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 pain medications taken for chronic pain conditions for the duration of the study.
* Have daily symmetrical foot pain secondary to peripheral neuropathy present for at least 6 months and as diagnosed through use of the Michigan Neuropathy Screening Instrument Part B ≥3 (©University of Michigan).
* Have a history and current diagnosis of type 1 or type 2 diabetes mellitus.
* Have stable glycemic control as indicated by a glycated hemoglobin ≤11 at time of screening.
* Are men, or women able to abide by reproductive and contraceptive requirements.

Exclusion Criteria:

* 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.
* Have a substance use disorder as defined by the Diagnostic and Statistical Manual of Mental Disorders (5th edition; DSM-5; American Psychiatric Association).
* Have had cancer within 2 years of baseline, except for cutaneous basal cell or squamous cell carcinoma resolved by excision.
* Are, in the judgment of the investigator, actively suicidal and therefore deemed to be at significant risk for suicide.
* Have a positive human immunodeficiency virus (HIV) test result at screening.
* Have an intolerance to acetaminophen or paracetamol or any of its excipients.
* Have a history of alcohol, illicit drug, analgesic or narcotic use disorder within 2 years prior to screening.
* Have a current drug-induced neuropathy, for example, due to some types of chemotherapy, or other types of peripheral neuropathy.
* Have known hereditary motor, sensory or autonomic neuropathies.
* Have a history within 2 years prior to screening or current evidence of syncope, presyncope, uncontrolled vertigo, or postural dizziness, judged to be clinically significant by the investigator.
* Have clinically significant active thyroid disease, including Hashimoto's thyroiditis.
* Are taking metformin therapy. Metformin Exception Limited dosages of metformin are allowed in this study. Additional exclusion criteria for participants taking metformin.

  * Have a history or presence of lactic acidosis.
  * Have a history or presence of severe hepatic disease including cirrhosis.
  * Have uncontrolled or unstable congestive heart failure.
  * Are taking carbonic anhydrase inhibitors if also taking metformin.
  * Have had a change in metformin therapy in the last 12 weeks.
  * Have not maintained a stable dose of glucose-lowering agents other than metformin before randomization.
  * Are pregnant or breastfeeding.
  * Have fibromyalgia.