Efficacy and Safety of LX9211 in Participants With Postherpetic Neuralgia (RELIEF-PHN1)

A Phase 2, Double-blind, Randomized, Placebo-controlled, Parallel-group Study to Evaluate the Efficacy and Safety of LX9211 in the Treatment of Postherpetic Neuralgia (RELIEF-PHN1)

Evaluation of the efficacy of LX9211 compared to placebo in reducing pain related to postherpetic neuralgia over an 11 week assessment period.

Study Overview

• Status: Completed
• Conditions: Postherpetic Neuralgia
• Intervention / Treatment: Drug: Placebo; Drug: LX9211

• Study Type: Interventional
• Enrollment (Actual): 79
• Phase: Phase 2

Contacts and Locations

Study Locations

• Czechia
  • Choceň, Czechia, 565 01
    • Lexicon Investigational Site (138)
  • Pardubice, Czechia, 53002
    • Lexicon Investigational Site (140)
  • Prague, Czechia, 100 00 00
    • Lexicon Investigational Site (136)
  • Prague, Czechia, 12000
    • Lexicon Investigational Site (137)
  • Prague, Czechia, 13000
    • Lexicon Investigational Site (141)
  • Prague, Czechia, 16000
    • Lexicon Investigational Site (135)
• Poland
  • Katowice, Poland, 40-282
    • Lexicon Investigational Site (128)
  • Katowice, Poland, 640-748
    • Lexicon Investigational Site (130)
  • Lublin, Poland, 20-064
    • Lexicon Investigational Site (134)
  • Warsaw, Poland, 01-868
    • Lexicon Investigational Site (133)
• United States
  • Arizona
    • Scottsdale, Arizona, United States, 85258
      • Lexicon Investigational Site
    • Tucson, Arizona, United States, 85741
      • Lexicon Investigational Site
  • California
    • Greenbrae, California, United States, 94904
      • Lexicon Investigational Site
  • Florida
    • Brandon, Florida, United States, 33511
      • Lexicon Investigational Site
    • Miami, Florida, United States, 33032
      • Lexicon Investigational Site (113)
    • Miami, Florida, United States, 33144
      • Lexicon Investigational Site
    • Miami, Florida, United States, 33174
      • Lexicon Investigational Site
    • Ormond Beach, Florida, United States, 32174
      • Lexicon Investigational Site
    • Winter Park, Florida, United States, 32789
      • Lexicon Investigational Site
  • Georgia
    • Marietta, Georgia, United States, 30060
      • Lexicon Investigational Site (147)
  • Illinois
    • Flossmoor, Illinois, United States, 60422
      • Lexicon Investigational Site
    • Wauconda, Illinois, United States, 60084
      • Lexicon Investigational Site
  • Massachusetts
    • Boston, Massachusetts, United States, 02131
      • Lexicon Investigational Site
  • Michigan
    • Canton, Michigan, United States, 48187
      • Lexicon Investigational Site
  • Missouri
    • Hazelwood, Missouri, United States, 63042
      • Lexicon Investigational Site
  • New Mexico
    • Albuquerque, New Mexico, United States, 87102
      • Lexicon Investigational Site
  • North Carolina
    • Cary, North Carolina, United States, 27518
      • Lexicon Investigational Site (148)
  • Pennsylvania
    • Jenkintown, Pennsylvania, United States, 19046
      • Lexicon Investigational Site
  • Texas
    • Baytown, Texas, United States, 77521
      • Lexicon Investigational Site
    • Victoria, Texas, United States, 77901
      • Lexicon Investigational Site
  • Utah
    • Salt Lake City, Utah, United States, 84102
      • Lexicon Investigational Site
  • Wisconsin
    • Kenosha, Wisconsin, United States, 53144
      • Lexicon Investigational Site

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Participant has given written informed consent to participate in the study in accordance with local regulations
• Adult male and female participants ≥18 years of age at the time of screening
• Postherpetic neuralgia (PHN) pain that is present for ≥3 months after healing of herpes zoster skin rash affecting a single dermatome (Participants with more than 1 involved dermatome may also be included, provided the affected dermatomes are contiguous)
• Moderate to severe pain as confirmed by average pain score using scores recorded in the pain diary in the 14 days prior to randomization

Exclusion Criteria:

• Presence of other painful conditions that may confound assessment or self-evaluation of PHN
• History of major depressive episode, active, significant psychiatric disorders
• History of clinically significant drug or alcohol use disorder
• PHN affecting the face
• Use of opioid medications for management of PHN within the 2 months prior to Screening Visit
• Use of Non-steroidal anti-inflammatory drugs (NSAIDs) for the specific treatment of PHN pain

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Placebo; Following a 2-week Single-blind Run-in period, participants will receive a single loading dose of matching-placebo to LX9211 tablet, orally, on Day 1 and maintenance doses, orally, once daily from Day 2 to Week 6.	Drug: Placebo; LX9211 matching-placebo, tablets will be administered orally.
Experimental: LX9211; Following a 2-week Single-blind Run-in period, participants will receive a single loading dose of 200 milligrams (mg) tablet, orally, on Day 1 and maintenance doses of 20 mg, orally, once daily from Day 2 to Week 6.	Drug: LX9211; LX9211 tablets will be administered orally.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change From Baseline (Week 2 of the Run-in Period) in Average Daily Pain Score (ADPS)	ADPS is based on question 5 of Zoster Brief Pain Inventory (ZBPI) and assessed on an 11-point numerical rating scale where, 0 = No Pain to 10 = pain as bad as you can imagine. Higher ADPS scores indicates a worse outcome. Negative change from baseline indicates no pain.	Baseline (Week 2 of the Run-in period) to Week 6

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change From Baseline in Pain Interfering With Sleep Based on Question 9F of the ZBPI at Week 6	Pain interfering with sleep is based on Question 9F of the ZBPI "Indicate the one number that describes how, in the past 24-hours shingles pain has interfered with your: Sleep; 0 = does not interfere to 10 = Completely interferes. Higher the number, the worsening of sleep due to pain interference. Negative change from baseline indicates no interference in sleep. Pain interfering with sleep was based on the daily pain diary data based on Q 9F of the ZBPI.	Baseline to Week 6
Percentage of Participants With ≥30% Reduction in Pain Intensity in ADPS From Baseline at Week 6	ADPS is based on question 5 of Zoster Brief Pain Inventory (ZBPI) and assessed on an 11-point numerical rating scale where, 0 = No Pain to 10 = pain as bad as you can imagine. Higher ADPS scores indicated a worse outcome.	Baseline to Week 6
Percentage of Participants With ≥50% Reduction in Pain Intensity in ADPS From Baseline at Week 6	ADPS is based on question 5 of ZBPI and assessed on an 11-point numerical rating scale where, 0 = No Pain to 10 = pain as bad as you can imagine. Higher ADPS scores indicated a worse outcome.	Baseline to Week 6
Change From Baseline in Interference in General Activity, Mood, Walking Ability, Normal Work, Relations With Other People, Sleep, and Enjoyment of Life Interference Based on the Questions 9A-G of the ZBPI	The ZBPI, a 9-item questionnaire, assesses the severity of pain and its impact on functioning in participants with postherpetic neuralgia (PHN). Each question concerning daily activity (General Activity, Mood, Walking Ability, Normal Work, Relations With Other People, Sleep, and Enjoyment of Life) was scored on a scale from 0 to 10, where 0 indicated no interference and 10 indicated complete interference. Higher ZBPI score indicates a worse outcome. Negative change from baseline indicates no interference in all daily activities. The pain interference at Week 6 in this outcome measure was based on data collected on the ZBPI administered at the Week 6 in-person clinic visit.	Baseline to Week 6
Number of Participants Discontinuing Treatment Due to Lack of Efficacy Defined as Increase in ADPS From Baseline of ≥30% Based on Question 5 of the ZBPI	ADPS is based on question 5 of ZBPI and assessed on an 11-point numerical rating scale where, 0 = No Pain to 10 = pain as bad as you can imagine.	Baseline to Week 6
Patient Global Impression of Change (PGIC) at Week 6	PGIC is assessed on a 7-point rating scale where 1= very much improved to 7 = very much worse. Higher scores indicate worse outcomes.	Baseline to Week 6
Time to Loss of Efficacy From Week 6 to Week 11 Among Participants Achieving ≥30% Reduction in Pain Intensity in ADPS Based on Question 5 of the ZBPI.	ADPS is based on question 5 of ZBPI and assessed on an 11-point numerical rating scale where, 0 = No Pain to 10 = pain as bad as you can imagine.	Week 6 to Week 11
Number of Participants With Treatment-emergent Adverse Events (TEAEs)	Adverse Events (AEs) are defined as any sign, symptom, or diagnosis/disease that is unfavorable or unintended, that is new, or if pre-existing, worsens in participants administered a pharmaceutical product and that does not necessarily have a causal relationship with this treatment. Treatment-emergent AEs are defined as any AEs reported after the first dose of double-blind study medication on study Day 1.	From first dose of study drug up to end of double-blind treatment period (up to Week 6) and end of single-blind treatment period (up to Week 11)

Collaborators and Investigators

• Sponsor: Lexicon Pharmaceuticals
• Investigators: Study Director: Suma Gopinathan, PhD, Lexicon Pharmaceuticals

Publications and helpful links

General Publications

• Luo G, Chen L, Kostich WA, Hamman B, Allen J, Easton A, Bourin C, Gulianello M, Lippy J, Nara S, Maishal TK, Thiyagarajan K, Jalagam P, Pattipati SN, Dandapani K, Dokania M, Vattikundala P, Sharma V, Elavazhagan S, Verma MK, Das ML, Wagh S, Balakrishnan A, Johnson BM, Santone KS, Thalody G, Denton R, Saminathan H, Holenarsipur VK, Kumar A, Rao A, Putlur SP, Sarvasiddhi SK, Shankar G, Louis JV, Ramarao M, Conway CM, Li YW, Pieschl R, Tian Y, Hong Y, Ditta J, Mathur A, Li J, Smith D, Pawluczyk J, Sun D, Yip S, Wu DR, Vetrichelvan M, Gupta A, Wilson A, Gopinathan S, Wason S, Bristow L, Albright CF, Bronson JJ, Macor JE, Dzierba CD. Discovery of (S)-1-((2',6-Bis(difluoromethyl)-[2,4'-bipyridin]-5-yl)oxy)-2,4-dimethylpentan-2-amine (BMS-986176/LX-9211): A Highly Selective, CNS Penetrable, and Orally Active Adaptor Protein-2 Associated Kinase 1 Inhibitor in Clinical Trials for the Treatment of Neuropathic Pain. J Med Chem. 2022 Mar 24;65(6):4457-4480. doi: 10.1021/acs.jmedchem.1c02131. Epub 2022 Mar 8.

Study record dates

Study Major Dates

• Study Start (Actual): December 10, 2020
• Primary Completion (Actual): November 18, 2022
• Study Completion (Actual): December 28, 2022

Study Registration Dates

• First Submitted: December 4, 2020
• First Submitted That Met QC Criteria: December 4, 2020
• First Posted (Actual): December 10, 2020

Study Record Updates

• Last Update Posted (Actual): February 13, 2026
• Last Update Submitted That Met QC Criteria: January 27, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Nervous System Diseases; Neuromuscular Diseases; Peripheral Nervous System Diseases; Neuralgia; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Neuralgia, Postherpetic
• Other Study ID Numbers: LX9211.1-202-PHN; 2020-004639-26 (EudraCT Number)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Qualified researchers may request access to patient level data and related study documents including the clinical study report, study protocol with any amendments, blank case report form, statistical analysis plan, and dataset specifications. Patient level data will be anonymized and study documents will be redacted to protect the privacy of trial participants.
• 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