Dose Response Study of EMA401 in Patients With Post-herpetic Neuralgia (PHN) (EMPHENE)

A Double-blind, Placebo-controlled, Randomized Dose Ranging Trial to Determine the Safety and Efficacy of Three Dose Levels of EMA401 in Reducing 24-hour Average Pain Intensity Score in Patients With Post-herpetic Neuralgia

Status

Active, not recruiting

Phases

Phase 2

Study type

Interventional

Source

JPRN

Registry ID

JPRN-jRCT2080223760

Enrollment

360

Registered

2017-12-21

Start date

2017-06-27

Completion date

Unknown

Last updated

2026-06-29

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Post-herpetic Neuralgia

Interventions

investigational material(s) Generic name etc : EMA401 INN of investigational material : Olodanrigan Therapeutic category code : 114 Antipyretics, analgesics and anti-inflammatory agents Dosage and Adm

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: * At the time of Screening, have documented diagnosis of PHN (ICD-10 code B02.29), defined as pain in the region of the rash persisting for more than 6 months after onset of herpes zoster rash. * Be assessed as suffering from moderate to severe neuropathic pain across the Screening epoch (NRS >= 4). * Patients must have documented past and/or ongoing inadequate treatment response (having insufficient pain relief with treatment or inability to tolerate) to at least 2 different prescribed therapies commonly used to treat and considered effective by the Investigator for the treatment of PHN.

Exclusion criteria

Exclusion criteria: * History or current diagnosis of electrocardiogram (ECG) abnormalities indicating significant risk of safety for patients participating in the study. * Major depressive episode within 6 months prior to Screening and/or a history of diagnosed recurrent major depressive disorder according to Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-V) diagnostic criteria. * Women of child-bearing potential, defined as all women physiologically capable of becoming pregnant. * Have evidence of significant renal insufficiency or pre-existing liver condition. * Have platelets = 8%. Those who do not have a known diagnosis of diabetes with a hemoglobin A1c > 7%. * Have previously received herpes zoster vaccine. * Patient is unwilling or unable to complete daily e-Diary. Other protocol-defined inclusion/exclusion criteria may apply.

Design outcomes

Primary

Measure	Time frame
efficacy Dose-response in change in weekly mean of the 24-hour average pain score, using an 11-point Numeric Rating Scale (NRS), from Baseline to Week 12 [ Time Frame: Baseline, Week 12 ]	—

Secondary

Measure	Time frame
efficacy Change in weekly mean 24-hour average pain score (using the 11 point Numerical Rating Scale) from Baseline to Week 12 [ Time Frame: Baseline, Week 12 ] efficacy Change in Brief Pain Inventory-Short Form interference total score from Baseline to Week 12 [ Time Frame: Baseline, Week 12 ] efficacy Change in weekly mean of the 24-hour worst pain score, using an 11-point NRS, from Baseline to Week 12 [ Time Frame: Baseline, Week 12 ] efficacy Patient Global Impression of Change at Week 12 [ Time Frame: Week 12 ] efficacy Percentage of patients meeting responder criteria from Baseline to Week 12 [ Time Frame: Baseline, Week 12 ] efficacy Change in Insomnia Severity Index from Baseline to Week 12 [ Time Frame: Baseline, Week 12 ] efficacy Change in Neuropathic Pain Symptom Inventory from Baseline to Week 12 [ Time Frame: Baseline, Week 12 ] pharmacokinetics Pharmacokinetics of EMA401: Tmax [ Time Frame: Week 8, Week 12 ] pharmacokinetics Pharmacokinetics of EMA401: Cmax [ Time Frame: Week 8, Week 12 ] pharmacokinetics Pharmacokinetics of EMA401: AUC [ Time Frame: Week 8, Week 12 ] pharmacokinetics Exposure-response (decrease in pain intensity) [ Time Frame: Week 8, Week 12 ]	—

Measure

Time frame

efficacy Change in weekly mean 24-hour average pain score (using the 11 point Numerical Rating Scale) from Baseline to Week 12 [ Time Frame: Baseline, Week 12 ] efficacy Change in Brief Pain Inventory-Short Form interference total score from Baseline to Week 12 [ Time Frame: Baseline, Week 12 ] efficacy Change in weekly mean of the 24-hour worst pain score, using an 11-point NRS, from Baseline to Week 12 [ Time Frame: Baseline, Week 12 ] efficacy Patient Global Impression of Change at Week 12 [ Time Frame: Week 12 ] efficacy Percentage of patients meeting responder criteria from Baseline to Week 12 [ Time Frame: Baseline, Week 12 ] efficacy Change in Insomnia Severity Index from Baseline to Week 12 [ Time Frame: Baseline, Week 12 ] efficacy Change in Neuropathic Pain Symptom Inventory from Baseline to Week 12 [ Time Frame: Baseline, Week 12 ] pharmacokinetics Pharmacokinetics of EMA401: Tmax [ Time Frame: Week 8, Week 12 ] pharmacokinetics Pharmacokinetics of EMA401: Cmax [ Time Frame: Week 8, Week 12 ] pharmacokinetics Pharmacokinetics of EMA401: AUC [ Time Frame: Week 8, Week 12 ] pharmacokinetics Exposure-response (decrease in pain intensity) [ Time Frame: Week 8, Week 12 ]

—

Countries

Asia except Japan, Europe, Japan, North America, Oceania

Outcome results

None listed

Source: JPRN (via WHO ICTRP) · Data processed: Jul 3, 2026