Efficacy and Safety of SIKD1977 in Combination with Standard Treatment for Postherpetic Neuralgia: Study Protocol for a Double Blind, Placebo-Controlled, Randomized, Multicenter, Phase 2 Clinical Trial

Abstract

Purpose

Postherpetic neuralgia (PHN) is the most common chronic complication of herpes zoster, associated with poor quality of life and increased patient and healthcare resource expenditure. This randomized controlled trial aims to evaluate the efficacy and safety of SIKD1977 (Sogeonjungtang) in combination with standard treatment and estimate an effective dose for treating PHN.

Patients and Methods

This is a protocol for a randomized, placebo-controlled, double-blind, multicenter trial. A total of 90 eligible participants with PHN will be recruited from three hospitals and randomly allocated to high-dose group, low-dose group, or placebo group in a 1:1:1 ratio. The trial will involve a 6-week oral administration of SIKD1977/placebo, and a 1-week follow-up period. The primary outcome will be the weekly average change in average daily pain score (ADPS) from baseline to the end of treatment. The secondary outcomes will include the weekly average changes in ADPS from baseline to week 2, 4, and 7, differences in Short-Form McGill Pain Questionnaire, Visual analogue scale, 5-level EuroQol-5 dimensions, Patient Global Impression of Change, and consumption of rescue drugs. All adverse events will be assessed during the trial.

Conclusion

This study will provide evidence for the efficacy and safety of SIKD1977, and an effective dose for PHN.

Trial Registration

This protocol has been registered in the Clinical Research Information Service with the identification code KCT0007939.

Keywords:

• postherpetic neuralgia
• herbal medicine
• SIKD1977
• Sogeonjungtang
• randomized controlled trial
• protocol

Abbreviations

ADPS, average daily pain score; ANCOVA, analysis of covariance; e-CRF, electronic case report form; EQ-5D-5L, 5-level EuroQol-5 dimension; FAS, full analysis set; IRB, Institutional Review Board; IWRS, Interactive Web Response System; NRS, numeric rating scale; GIC, Patient Global Impression of Change; PHN, postherpetic neuralgia; PP, per-protocol; SF-MPQ, Short-Form McGill Pain Questionnaire; SGJT, Sogeonjungtang; TCA, tricyclic antidepressant; VAS, visual analogue scale.

Trial Status

The final protocol version is 2.2, dated 26 September 2022. The recruitment will begin on 1 February 2023. We anticipate that it would be take 2 years to complete this trial.

Data Sharing Statement

Data and material from this trial are available upon reasonable request and approved by the corresponding author.

Author Contributions

Hyo-Rim Jo is the first author. All authors made a significant contribution to the work reported, whether that is in the conception, study design, execution, acquisition of data, analysis and interpretation, or in all these areas; took part in drafting, revising, or critically reviewing the article; have agreed on the journal to which the article has been submitted; gave final approval of the version to be published; and agree to be accountable for all aspects of the work. And they will also accept the responsibility for the study protocol.

Disclosure

Yong-Gyun Kim and Young-Ee Kwon are employees of Samik Pharmaceutical Company, the sponsor of this study. None of the other authors were financially compensated for their collaboration in this project or for the development of this paper. The authors report no other conflicts of interest in this work.

Additional information

Funding

This research is supported by a grant of the Korea Health Technology R&D Project through the Korea Health Industry Development Institute, funded by the Ministry of Health & Welfare, Republic of Korea (grant number HF22C0071). The funding source has no role in the design of the study, collection, analysis, and interpretation of data, and in writing the manuscript.