A Phase 2 interventional study of Placebo and LX9211 in Postherpetic Neuralgia, sponsored by Lexicon Pharmaceuticals. Completed at 32 sites in 3 countries. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-02-13.
Sponsored by Lexicon Pharmaceuticals · Phase 2, Interventional, and Treatment
Evaluation of the efficacy of LX9211 compared to placebo in reducing pain related to postherpetic neuralgia over an 11 week assessment period.
Exclusion Criteria:
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
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 matching-placebo, tablets will be administered orally.
LX9211 tablets will be administered orally.
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.
Time frame: Baseline (Week 2 of the Run-in period) to Week 6
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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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)
Participants took part in the study at multiple investigative sites from 10 Dec 2020 to 28 Dec 2022.
| Milestone | Placebo | LX9211 |
|---|---|---|
| Started | 41 | 38 |
| Completed | 34 | 21 |
| Not completed | 7 | 17 |
| Withdrew: Adverse event | 4 | 13 |
| Withdrew: Withdrawal by subject | 1 | 2 |
| Withdrew: Lack of efficacy | 1 | 0 |
| Withdrew: Reason not specified | 1 | 2 |
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.
| score on a scale | Placebo | LX9211 |
|---|---|---|
| Change From Baseline (Week 2 of the Run-in Period) in Average Daily Pain Score (ADPS) | -1.62 ± 0.360 | -2.42 ± 0.397 |
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.
| score on a scale | Placebo | LX9211 |
|---|---|---|
| Change From Baseline in Pain Interfering With Sleep Based on Question 9F of the ZBPI at Week 6 | -1.43 ± 0.323 | -2.04 ± 0.364 |
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.
| percentage of participants | Placebo | LX9211 |
|---|---|---|
| Percentage of Participants With ≥30% Reduction in Pain Intensity in ADPS From Baseline at Week 6 | 34.15 | 42.11 |
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.
| percentage of participants | Placebo | LX9211 |
|---|---|---|
| Percentage of Participants With ≥50% Reduction in Pain Intensity in ADPS From Baseline at Week 6 | 19.51 | 23.68 |
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.
| score on a scale | Placebo | LX9211 |
|---|---|---|
| General Activity: Change at Week 6 | -0.52 ± 0.392 | -1.75 ± 0.417 |
| Mood: Change at Week 6 | -1.52 ± 0.407 | -2.36 ± 0.435 |
| Walking Ability: Change at Week 6 | -0.28 ± 0.373 | -0.72 ± 0.391 |
| Normal Work: Change at Week 6 | -0.61 ± 0.383 | -1.28 ± 0.397 |
| Relations With Other People: Change at Week 6 | -0.89 ± 0.381 | -1.27 ± 0.400 |
| Relations With Sleep: Change at Week 6 | -1.61 ± 0.370 | -1.66 ± 0.382 |
| Enjoyment of Life: Change at Week 6 | -1.13 ± 0.405 | -1.93 ± 0.435 |
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.
| Participants | Placebo | LX9211 |
|---|---|---|
| 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 | 1 | 0 |
PGIC is assessed on a 7-point rating scale where 1= very much improved to 7 = very much worse. Higher scores indicate worse outcomes.
| score on a scale | Placebo | LX9211 |
|---|---|---|
| Patient Global Impression of Change (PGIC) at Week 6 | 3.06 ± 0.222 | 2.65 ± 0.265 |
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.
| weeks | Placebo | LX9211 |
|---|---|---|
| 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. | NA (NA to NA) | NA (NA to NA) |
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.
| Participants | Placebo (Double-blind Treatment Period) | LX9211 (Double-blind Treatment Period) | Placebo (Single-blind Placebo Safety Follow-up Period) | LX9211 (Single-blind Placebo Safety Follow-up Period) |
|---|---|---|---|---|
| Number of Participants With Treatment-emergent Adverse Events (TEAEs) | 13 | 24 | 9 | 5 |
Collected over 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). Non-serious events are listed at a 5% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Placebo (Double-blind Treatment Period) | 0/41 (0%) | 0/41 (0%) | 6/41 (14.6%) |
| LX9211 (Double-blind Treatment Period) | 0/38 (0%) | 0/38 (0%) | 24/38 (63.2%) |
| Placebo (Single-blind Placebo Safety Follow-up Period) | 0/38 (0%) | 0/38 (0%) | 2/38 (5.3%) |
| LX9211 (Single-blind Placebo Safety Follow-up Period) | 0/31 (0%) | 0/31 (0%) | 1/31 (3.2%) |
| Event | Placebo (Double-blind Treatment Period) | LX9211 (Double-blind Treatment Period) | Placebo (Single-blind Placebo Safety Follow-up Period) | LX9211 (Single-blind Placebo Safety Follow-up Period) |
|---|---|---|---|---|
| DizzinessNervous system disorders | 2/41 | 11/38 | 0/38 | 0/31 |
| ConstipationGastrointestinal disorders | 0/41 | 4/38 | 0/38 | 0/31 |
| HeadacheNervous system disorders | 2/41 | 4/38 | 1/38 | 1/31 |
| NauseaGastrointestinal disorders | 0/41 | 3/38 | 0/38 | 1/31 |
| Urinary tract infectionInfections and infestations | 2/41 | 3/38 | 2/38 | 1/31 |
| DiarrheaGastrointestinal disorders | 3/41 | 0/38 | 0/38 | 0/31 |
| VertigoEar and labyrinth disorders | 0/41 | 2/38 | 0/38 | 0/31 |
| Dry mouthGastrointestinal disorders | 0/41 | 2/38 | 0/38 | 0/31 |
| Balance disorderNervous system disorders | 0/41 | 2/38 | 0/38 | 0/31 |
| SomnolenceNervous system disorders | 0/41 | 2/38 | 0/38 | 0/31 |
Modified Intent-to-Treat (mITT) population included all randomized participants who had taken at least 1 dose of study drug.
| Age, Continuous(years) | Placebo | LX9211 | Total |
|---|---|---|---|
| Mean | 63.6 ± 12.5 | 65.4 ± 11.7 | 64.5 ± 12.1 |
| Sex: Female, Male(Participants) | Placebo | LX9211 | Total |
|---|---|---|---|
| Female | 24 | 23 | 47 |
| Male | 17 | 15 | 32 |
| Ethnicity (NIH/OMB)(Participants) | Placebo | LX9211 | Total |
|---|---|---|---|
| Hispanic or Latino | 12 | 11 | 23 |
| Not Hispanic or Latino | 29 | 27 | 56 |
| Unknown or Not Reported | 0 | 0 | 0 |
| Race (NIH/OMB)(Participants) | Placebo | LX9211 | Total |
|---|---|---|---|
| American Indian or Alaska Native | 0 | 0 | 0 |
| Asian | 0 | 0 | 0 |
| Native Hawaiian or Other Pacific Islander | 0 | 0 | 0 |
| Black or African American | 2 | 0 | 2 |
| White | 39 | 37 | 76 |
| More than one race | 0 | 0 | 0 |
| Unknown or Not Reported | 0 | 1 | 1 |
Documents are hosted by the registry — open the source record to download them.
Plan to share: Yes — 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.
Supporting information: Study protocol, Sap, Csr
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Lexicon Pharmaceuticals