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

A Phase 2, Randomized, Double-Blind, Placebo Controlled, Dose-Ranging Study to Evaluate LY3556050 in Adult Participants With Diabetic Peripheral Neuropathic Pain

The main purpose of this study is to determine the safety and efficacy of LY3556050 versus placebo in participants with diabetic peripheral neuropathic pain (DPNP). The study will lasts approximately 24 weeks, across 3 study periods.

Study Overview

• Status: Completed
• Conditions: Diabetic Peripheral Neuropathy
• Intervention / Treatment: Drug: Placebo; Drug: Mazisotine

• Study Type: Interventional
• Enrollment (Actual): 404
• Phase: Phase 2

Contacts and Locations

Study Locations

• Czechia
  • Olomouc, Czechia, 779 00
    • Agentura Science Pro
  • Hradec Králové Region
    • Broumov, Hradec Králové Region, Czechia, 550 01
      • EDUMED - Broumov
  • Praha 1
    • Prague, Praha 1, Czechia, 11000
      • Diabet2 s.r.o., diabetologicka a interni ambulance
  • Praha 6
    • Prague, Praha 6, Czechia, 160 00
      • Neurologická Ambulance - Forbeli
  • Praha, Hlavní Mešto
    • Prague, Praha, Hlavní Mešto, Czechia, 160 00
      • FLEDIP - Na dlouhem lanu
    • Prague, Praha, Hlavní Mešto, Czechia, 140 00
      • DiaVize s.r.o.
  • Rychnov Nad Kněžnou
    • European Union, Rychnov Nad Kněžnou, Czechia, 516 01
      • Vestra Clinics
• Japan
  • Fukuoka, Japan, 819-0168
    • Kunisaki Makoto Clinic
  • Osaka, Japan, 559-0012
    • Minamiosaka Hospital
  • Shizuoka, Japan, 422-8006
    • Plumeria DM Clinic
  • Ehime
    • Matsuyama, Ehime, Japan, 790-0067
      • Matsuyama Shimin Hospital
  • Gunma
    • Maebashi, Gunma, Japan, 370-3573
      • Kikuchi Naika Clinic
  • Hiroshima
    • Kure, Hiroshima, Japan, 737-0023
      • Kure Medical Center
  • Hokkaido
    • Asahikawa, Hokkaido, Japan, 070-8530
      • Japanese Red Cross Asahikawa Hospital
  • Kanagawa
    • Yokohama, Kanagawa, Japan, 232-0064
      • Yokohama Minoru Clinic
  • Osaka
    • Suita-shi, Osaka, Japan, 565-0853
      • Medical Corporation Heishinkai OCROM Clinic
  • Saitama
    • Sokashi, Saitama, Japan, 340-0015
      • Sugiura Internal Medicine Clinic
  • Shizuoka
    • Shizuoka, Shizuoka, Japan, 424-0855
      • Suruga Clinic
  • Tokyo
    • Ootaku, Tokyo, Japan, 143-0015
      • Medical Corporation Sato Medical clinic
    • Shinjuku-ku, Tokyo, Japan, 160-0008
      • Heishinkai Medical Group ToCROM Clinic
• Poland
  • Greater Poland Voivodeship
    • Poznan, Greater Poland Voivodeship, Poland, 61-853
      • Nzoz Neuro-Kard Ilkowski i Partnerzy SPL
  • Kuyavian-Pomeranian Voivodeship
    • Torun, Kuyavian-Pomeranian Voivodeship, Poland, 87-100
      • MICS Centrum Medyczne Toruń
  • Lesser Poland Voivodeship
    • Krakow, Lesser Poland Voivodeship, Poland, 31-261
      • Medyczne Centrum Diabetologiczno Endokrynologiczno Metaboliczne DIAB-ENDO-MET
  • Lower Silesian Voivodeship
    • Wroclaw, Lower Silesian Voivodeship, Poland, 51-162
      • Centrum Badań Klinicznych Piotr Napora lekarze sp.p.
  • Masovian Voivodeship
    • Warsaw, Masovian Voivodeship, Poland, 00-874
      • MICS Centrum Medyczne Warszawa
    • Wyszków, Masovian Voivodeship, Poland, 07-200
      • Samodzielny Publiczny Zespol Opieki Zdrowotnej w Wyszkow
  • Podlaskie Voivodeship
    • Biaystok, Podlaskie Voivodeship, Poland, 15-351
      • Zdrowie Osteo-Medic
  • Silesian Voivodeship
    • Katowice, Silesian Voivodeship, Poland, 40-081
      • Centrum Medyczne Pratia Katowice
    • Katowice, Silesian Voivodeship, Poland, 40-648
      • Pro Familia Altera
    • Ruda Śląska, Silesian Voivodeship, Poland, 41-709
      • NZOZ Przychodnia Specjalistyczna Andrzej Wittek, Henryk Rudzki
  • Łódź Voivodeship
    • Lodz, Łódź Voivodeship, Poland, 90-338
      • Centrum Terapii Wspolczesnej J. M. Jasnorzewska Spolka Komandytowo-Akcyjna
• South Korea
  • Kyǒnggi-do
    • Sosa-gu, Kyǒnggi-do, South Korea, 14754
      • Sejong General Hospital
  • Seoul-teukbyeolsi [Seoul]
    • Seoul, Seoul-teukbyeolsi [Seoul], South Korea, 06351
      • Samsung Medical Center
    • Seoul, Seoul-teukbyeolsi [Seoul], South Korea, 01830
      • Nowon Eulji Medical Center, Eulji University
    • Seoul, Seoul-teukbyeolsi [Seoul], South Korea, 05030
      • Konkuk University Medical Center
  • Taejǒn-Kwangyǒkshi
    • Daejeon, Taejǒn-Kwangyǒkshi, South Korea, 01830
      • Eulji University Hospital
• United States
  • Arizona
    • Chandler, Arizona, United States, 85225
      • The Institute for Liver Health II dba Arizona Clinical Trials - Mesa
    • Scottsdale, Arizona, United States, 85260
      • Headlands Research - Scottsdale
    • Tucson, Arizona, United States, 85741
      • Orange Grove Family Practice
  • Arkansas
    • Little Rock, Arkansas, United States, 72211
      • Preferred Research Partners
  • California
    • Canoga Park, California, United States, 91303
      • Hope Clinical Research, Inc.
    • Northridge, California, United States, 91325
      • Valley Clinical Trials, Inc.
    • Sacramento, California, United States, 95821
      • Northern California Research - Sacramento
  • Connecticut
    • Hamden, Connecticut, United States, 06517
      • CMR of Greater New Haven, LLC
  • Florida
    • Miami, Florida, United States, 33165
      • New Horizon Research Center
    • Miami, Florida, United States, 33135
      • Suncoast Research Group
  • Illinois
    • Chicago, Illinois, United States, 60611
      • Northwestern University
  • Kansas
    • Wichita, Kansas, United States, 67205
      • Alliance for Multispecialty Research, LLC
  • Kentucky
    • Lexington, Kentucky, United States, 40509
      • Alliance for Multispecialty Research, LLC
  • Louisiana
    • Lake Charles, Louisiana, United States, 70601
      • Care Access - Lake Charles
  • Massachusetts
    • Waltham, Massachusetts, United States, 02451
      • MedVadis Research Corporation
  • Mississippi
    • Ridgeland, Mississippi, United States, 39157
      • SKY Integrative Medical Center/SKYCRNG
  • Missouri
    • City of Saint Peters, Missouri, United States, 63303
      • StudyMetrix Research
    • Kansas City, Missouri, United States, 64114
      • Alliance for Multispecialty Research, LLC
    • Springfield, Missouri, United States, 65807
      • Clinvest Research LLC
  • Nevada
    • Las Vegas, Nevada, United States, 89128
      • Las Vegas Medical Research
  • New Jersey
    • East Brunswick, New Jersey, United States, 08816
      • UniMed Center
  • New York
    • Port Jefferson Station, New York, United States, 11776
      • North Suffolk Neurology
  • North Carolina
    • Hickory, North Carolina, United States, 28601
      • Lucas Research - Hickory
    • Morehead City, North Carolina, United States, 28557
      • Lucas Research, Inc
  • Oregon
    • Medford, Oregon, United States, 97504
      • Velocity Clinical Research, Medford
  • Pennsylvania
    • Philadelphia, Pennsylvania, United States, 19114
      • Tristar Clinical Investigations
    • West Chester, Pennsylvania, United States, 19380
      • Suburban Research Associates
  • Tennessee
    • Knoxville, Tennessee, United States, 37909
      • New Phase Research and Development
  • Texas
    • Austin, Texas, United States, 78731
      • FutureSearch Trials of Neurology
    • Houston, Texas, United States, 77040
      • Juno Research
    • Shavano Park, Texas, United States, 78231
      • Consano Clinical Research, LLC
  • Utah
    • West Jordan, Utah, United States, 84088
      • Velocity Clinical Research, Salt Lake City
  • Washington
    • Bellevue, Washington, United States, 98007
      • Northwest Clinical Research Center
    • Renton, Washington, United States, 98057
      • Rainier Clinical Research Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

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 90 days prior to day 1 with a hemoglobin A1c (HbA1c) ≤10 for T1D and HbA1c ≤11 for participants with T2D at time of screening.
• Have a history of daily peripheral neuropathic pain for at least 12 weeks based on participant 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 lower extremities for ≥6 months and diagnosed by a score of Part B ≥3 on Michigan Neuropathy Screening Instrument
• 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, except allowed concomitant pain medication permitted per protocol, for the duration of the study

  • 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 may impair self-assessment of pain due to DPNP.
• 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 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 in the judgement 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 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 of Mental Disorders (5th edition; DSM-5; American Psychiatric Association)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Placebo; Participants received a matching dose of placebo administered orally twice daily (BID) over a period of 12 weeks.	Drug: Placebo; Administered orally.
Experimental: Mazisotine 50 mg; Participants received mazisotine 50 milligrams (mg) administered orally BID over a period of 12 weeks.	Drug: Mazisotine; Administered orally.; Other Names: LY3556050
Experimental: Mazisotine 200 mg; Participants received mazisotine BID orally, starting at 50 mg and titrated weekly, reaching 100 mg BID by Week 2 and a target maintenance dose of 200 mg BID by Week 3, which was then maintained up to Week 12.	Drug: Mazisotine; Administered orally.; Other Names: LY3556050
Experimental: Mazisotine 400 mg; Participants received mazisotine BID orally, starting at 50 mg and titrated weekly, reaching 100 mg BID by Week 2, 200 mg BID by Week 3, and 300 mg BID by Week 4, until reaching a target maintenance dose of 400 mg BID by Week 5, which was then maintained up to Week 12.	Drug: Mazisotine; Administered orally.; Other Names: LY3556050

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mean Change From Baseline in Average Pain Intensity (API) as Measured by Weekly Average of Numeric Rating Scale (NRS) - Bayesian Model Averaging (BMA) Dose-response Model	The NRS was a single-item numeric scale used to describe pain severity. Participants were asked to rate their average pain over the past 24 hours, on a scale of 0 to 10: 0 = no pain, and 10 = pain as bad as you can imagine; a higher score indicates worse outcome (greater pain severity).; The mixed-model repeated measures (MMRM) model included the fixed, centered, categorical effects of region, baseline NRS average pain score, as well as concurrent use of allowed concomitant medications (yes vs. no based on interactive web response system [IWRS]), and visit. The adjusted dose response value from the MMRM was used for fitting a Bayesian model averaging (BMA) dose-response model.; Posterior mean change from baseline, 95 percent (%) credible interval was derived using Bayesian mixed model repeated measures. Data presented were posterior mean with 95% credible interval.	Baseline, Week 12
Mean Change From Baseline in Average Pain Intensity (API) as Measured by Weekly Average of Numeric Rating Scale (NRS) - Frequentist Repeated Measures (FRM) Analysis	The NRS was a single-item numeric scale used to describe pain severity. Participants were asked to rate their average pain over the past 24 hours, on a scale of 0 to 10: 0 = no pain, and 10 = pain as bad as you can imagine; a higher score indicates worse outcome (greater pain severity).; The Least Squares (LS) Mean was calculated using a frequentist repeated measures (FRM) analysis, where Change = treatment, time interval, treatment * time interval, region, average baseline pain severity category (mild or moderate versus [vs.] severe), concurrent use of allowed concomitant medication as entered in IWRS (yes versus no).	Baseline, Week 12

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mean Change From Baseline in Worst Pain Intensity (WPI) as Measured by Weekly Average of Numeric Rating Scale (NRS)	The NRS was a single-item numeric scale used to describe pain severity. Participants were asked to rate their worst pain intensity over the past 24 hours, on a scale of 0 to 10: 0 = no pain, and 10 = pain as bad as you can imagine; a higher score indicates worse outcome (greater pain severity).; The LS Mean was calculated using an FRM analysis, where Change = treatment, time interval, treatment * time interval, region, average baseline pain severity category (mild or moderate versus severe), concurrent use of allowed concomitant medication (yes versus no based on IWRS).	Baseline, Week 12
Mean Change From Baseline in Patient-Reported Outcomes Measurement Information System Pain Interference Short Form 8a (PROMIS PI SF8a)	The Patient-Reported Outcomes Measurement Information System Pain Interference Short Form 8a (PROMIS PI SF8a) was administered to measure self-reported consequences of pain on various aspects of the participant's life within the previous 7 days. The scale consists of 8 items, all measuring a single domain of pain interference, including impact on day-to-day activities, work around the home, household chores, family life, social activities, activities done for fun, enjoyment of social activities, and enjoyment of life. Each item was rated on a 5-point response scale ranging from "not at all" (1) to "very much" (5); the 8 item scores were summed to produce a raw score ranging from 8 (minimum) to 40 (maximum). The raw score was then converted to a T-score with a mean of 50 and a standard deviation of 10; higher T-scores indicate worse outcome (greater pain interference). Range cannot be specified in norm-based scores.	Baseline, Week 12
Mean Change From Baseline in Pain Interference With Sleep	Pain Interference with Sleep was assessed using a single-item measure: "To what extent did diabetic nerve pain interfere with your sleep last night?" Participants responded on a scale from 0 (minimum, "Not at all") to 4 (maximum, "Unable to sleep at all"); higher scores indicate worse outcome (greater sleep interference due to pain).; LS Mean was calculated using an FRM analysis, where Change = treatment, time interval, treatment * time interval, region, average baseline pain severity category (mild or moderate vs. severe), concurrent use of concomitant medication (yes vs. no based on IWRS).	Baseline, Week 12
Mean Change From Baseline in Patient-Reported Outcomes Measurement Information System Physical Functioning Short Form 10a (PROMIS PF SF10a)	The PROMIS PF SF10a was administered to assess self-reported physical function and physical activities across 10 items at the present time.The first 5 items assess current physical limitations (health in doing vigorous activities, walking more than one mile, climbing stairs, lifting or carrying groceries, and bending, kneeling, or stooping), each rated on a 5-point Likert scale ranging from "not at all" to "cannot do". The remaining 5 items are self-reported ability to perform specific physical activities such as chores,dressing themselves, bathing,sitting on and getting up from the toilet, each rated on a 5-point likert scale ranging from "without any difficulty" to "unable to do". The 10 item scores were summed to produce a raw score ranging from 10 (minimum) to 50 (maximum).The raw score was then converted to a T-score with a mean of 50 and a standard deviation of 10; higher T-scores indicate better outcome (greater physical function).Range cannot be specified in norm-based scores.	Baseline, Week 12
Mean Change From Baseline in Patient-Reported Outcomes Measurement Information System Sleep Disturbance Short Form 8b (PROMIS SD SF8b)	The Patient-Reported Outcomes Measurement Information System Sleep Disturbance Short Form 8b (PROMIS SD SF8b) was administered to assess perceptions of sleep quality, sleep depth, and restoration associated with sleep within the previous 7 days, including perceived difficulties and concerns with getting to sleep or staying asleep, and perceptions of the adequacy of and satisfaction with sleep. The scale consists of 8 items, all measuring a single domain of sleep disturbance. Each item was rated on a 5-point response scale ranging from "not at all" to "very much," "never" to "always," or "very poor" to "very good"; the 8 item scores were summed to produce a raw score ranging from 8 (minimum) to 40 (maximum). The raw score was then converted to a T-score with a mean of 50 and a standard deviation of 10; higher T-scores indicate worse outcome (greater sleep disturbance). Range cannot be specified in norm-based scores.	Baseline, Week 12
Mean Change From Baseline in Patient's Global Impression of Illness Severity as Measured by Patient's Global Impression-Severity (PGI-Severity)	The Patient's Global Impression-Severity (PGI-Severity) is a patient-reported single-item instrument designed to assess the participant's severity of diabetic nerve pain over the past week. The single item is rated on a 5-point Likert scale ranging from 1 (minimum, "very severe") to 5 (maximum, "none"); higher scores indicate better outcome (less pain severity).; The LS Mean was calculated using an FRM analysis, where Change = treatment, time interval, treatment * time interval, region, average baseline pain severity category (mild or moderate vs. severe), concurrent use of allowed concomitant medication (yes vs. no based on IWRS).	Baseline, Week 12
Mean Change From Baseline in Patient's Global Impression (PGI) of Illness Status as Measured by PGI-Status	The Patient's Global Impression-Status (PGI-Status) is a patient-reported single-item instrument designed to assess the participant's status with diabetic nerve pain. Three PGI-Status scales were administered to assess physical activity, usual activity, and sleep disturbance. For physical activity, participants rated their status at the present time; for usual activity and sleep disturbance, participants rated their overall status over the past week. Physical activity and usual activity were each rated on a 5-point Likert scale ranging from 1 (minimum, "extremely limited") to 5 (maximum, "not at all limited"); higher scores indicate better outcome (less limitation). Sleep disturbance was rated on a 5-point Likert scale ranging from 1 (minimum, "very much") to 5 (maximum, "not at all"); higher scores indicate better outcome (less sleep disturbance).	Baseline, Week 12
Patient's Global Impression of Change as Measured by Patient's Global Impression-Change (PGI-Change)	The Patient's Global Impression-Change (PGI-Change) is a patient-reported single-item instrument designed to assess the participant's rating of change in diabetic nerve pain since they began taking the study medication. Four PGI-Change scales were administered to assess diabetic nerve pain's impact on physical activities, usual activities, sleep disturbance, and overall change. Each item was rated on a 5-point Likert scale ranging from 1 (minimum, "much worse") to 5 (maximum, "much better"); higher scores indicate better outcome (greater improvement).	Week 12
Mean Change From Baseline in Neuropathy Total Symptom Score-6 (NTSS-6)	The NTSS-6 assessed the frequency and intensity of 6 diabetic peripheral neuropathic symptoms over the previous 7 days: (1) numbness and/or insensitivity, (2) prickling and/or tingling sensation, (3) burning sensation, (4) aching pain and/or tightness, (5) sharp, shooting, lancinating pain, and (6) allodynia and/or hyperalgesia. Each of the 6 symptoms was rated on two separate response scales: an intensity scale (Does not apply [0], Mild [1], Moderate [2], or Severe [3]) and a frequency scale (Never [0], Occasionally, less than 1/3 of the time [0], Often, 1/3 to 2/3 of the time [0.33], or Almost always, more than 2/3 of the time [0.66]). The total score was calculated as the weighted sum across all 6 symptoms, where intensity was given a weight of 1 and frequency was given a weight of 1/3, yielding a total score ranging from 0 (minimum, no symptoms) to 21.96 (maximum, most severe); higher scores indicate worse outcome (greater neuropathic symptom burden).	Baseline, Week 12
Total Amount of Rescue Medication Use as Measured by Average Daily Dosage	Acetaminophen was used as rescue medication during the treatment period. The total amount of rescue medication use was summarized as the average daily dosage at Week 12.	Week 12
Percentage of Participants With at Least One Use of Rescue Medication	Acetaminophen was used as rescue medication during the treatment period. The percentage of participants with at least one use of rescue medication at Week 12 was reported.	Week 12
Pharmacokinetics (PK): Plasma Concentration of Mazisotine	Mazisotine plasma concentration was reported. The Measure Type was Median and the Measure of Dispersion/Precision was Inter-Quartile Range, where the lower and upper limits represented the 5th and 95th percentiles, respectively.	Postdose at Week 12

Collaborators and Investigators

• Sponsor: Eli Lilly and Company
• Investigators: Study Director: Call 1-877-CTLILLY (1-877-285-4559) or 1-317-615-4559 Mon - Fri 9 AM - 5 PM Eastern time (UTC/GMT - 5 hours, EST), Eli Lilly and Company

Publications and helpful links

Helpful Links

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

Study record dates

Study Major Dates

• Study Start (Actual): October 5, 2023
• Primary Completion (Actual): June 11, 2025
• Study Completion (Actual): June 11, 2025

Study Registration Dates

• First Submitted: October 3, 2023
• First Submitted That Met QC Criteria: October 3, 2023
• First Posted (Actual): October 10, 2023

Study Record Updates

• Last Update Posted (Actual): July 30, 2026
• Last Update Submitted That Met QC Criteria: July 6, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Nervous System Diseases; Neuromuscular Diseases; Neuralgia; Peripheral Nervous System Diseases
• Other Study ID Numbers: 18509; J2P-MC-LXBD (Other Identifier: Eli Lilly and Company); 2023-506127-29-00 (Other Identifier: EU Trial Number)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Anonymized individual patient level data will be provided in a secure access environment upon approval of a research proposal and a signed data sharing agreement.
• IPD Sharing Time Frame: Data are available 6 months after the primary publication and approval of the indication studied in the US and European Union (EU), whichever is later. Data will be indefinitely available for requesting.
• IPD Sharing Access Criteria: A research proposal must be approved by an independent review panel and researchers must sign a data sharing agreement.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; CSR

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No