A Study of LY3556050 in Adult Participants With Diabetic Peripheral Neuropathic Pain

Inclusion Criteria:

• Have a history and current diagnosis of Type 1 Diabetes (T1D) or Type 2 Diabetes (T2D) diagnosed for at least 6 months prior to screening.

• Have a stable glycemic control on stable diabetes treatment regimen for at least 90days prior to day 1 with a hemoglobin A1c (HbA1c) ≤10 for T1D and HbA1c ≤11 forparticipants with T2D at time of screening.

• Have a history of daily peripheral neuropathic pain for at least 12 weeks based onparticipant report or medical history.

• Have a visual analog scale (VAS) pain value ≥40 and <95 during screening.

• Have presence of diabetic peripheral neuropathy of symmetrical nature and in lowerextremities for ≥6 months and diagnosed by a score of Part B ≥3 on MichiganNeuropathy Screening Instrument

• Are willing to maintain a consistent regimen of any ongoing nonpharmacologicpain-relieving therapies (for example, physical therapy) and will not start any newnonpharmacologic pain-relieving therapies during study participation.

• Are willing to discontinue all medications taken for chronic pain conditions, exceptallowed concomitant pain medication permitted per protocol, for the duration of thestudy

• Have a body mass index ≤45 kilogram/square meter (kg/m²) (inclusive).

• Are men, or women able to abide by reproductive and contraceptive requirements.

Exclusion Criteria:

• History of other potentially causative and/or confounding sources of pain that mayimpair self-assessment of pain due to DPNP.

• Have had a procedure within the past 6 months intended to produce permanent sensoryloss in the target area of interest (for example, ablation techniques.

• Have had cancer within 2 years of baseline, except for cutaneous basal cell orsquamous cell carcinoma resolved by excision.

• Are, in the judgment of the investigator, actively suicidal and therefore deemed tobe at significant risk for suicide.

• Have in the judgement of the investigator, an acute, serious, or unstable medicalcondition or a history or presence of any other medical illness that would precludestudy participation.

• Have a positive HIV test result at screening.

• Have a surgery planned during the study for any reason.

• Have a substance use disorder as defined by the Diagnostic and Statistical Manual ofMental Disorders (5th edition; DSM-5; American Psychiatric Association)