165: IncobotulinumtoxinA in Postherpetic Neuralgia: Sustained Pain Improvement in the PaiNT Phase 2 Study

Topic: Clinical Science
Subtopic: Pain category (ICD-11), Chronic neuropathic pain, Drug development, Treatment/management

Background and Aims: Postherpetic neuralgia (PHN) causes persistent, often debilitating peripheral neuropathic pain (PNP) that can greatly restrict daily life. Many patients continue to struggle due to shortcomings of available treatments, highlighting the need for approaches that can meaningfully ease pain over time. The PaiNT study addresses this need by investigating how average daily pain (ADP) evolves over 20‑weeks in patients receiving a single incobotulinumtoxinA (incoBoNT-A, Xeomin®) treatment.

Methods: The PaiNT study enrolled adults with two distinct PNP conditions: postherpetic neuralgia or PNP following trauma or surgery. Participants received a single subcutaneous treatment of incoBoNT-A at a dose up to 300 units (up to 60 injections) into the painful area. Only PHN participants are included in this analysis. Pain was recorded as average daily pain (ADP) intensity (0-10 NRS) over 20 weeks and changes from baseline were summarized as weekly averages. Responder status was assessed weekly; persistence was summarized as the median number of weeks meeting the threshold during the 20‑week follow‑up.

Results: Across the 20‑week period, ADP intensity improved consistently in favour of incoBoNT-A compared to placebo. The greatest separation between treatment groups occurred at Week 6, when the adjusted mean difference to placebo was –1.14 points (p = 0.0488). Responder rates (≥30% and ≥50% pain reduction) were also higher in the incoBoNT-A group throughout the 20-week period. Statistically significant differences in ≥30% response were observed at multiple weeks. IncoBoNT‑A showed greater persistence of response across follow‑up compared to placebo, with median weeks in response of 16.5 vs 5.5 (≥30%) and 11.0 vs 4.5 (≥50%).

Conclusions: IncoBoNT‑A produced a clinically meaningful reduction in ADP intensity, with statistically significant separation from placebo at Week 6 and substantially longer maintenance of ≥30% and ≥50% improvement over 20 weeks, indicating a considerable and stable treatment effect in PHN.. Taken together, these findings indicate that a single incoBoNT-A treatment can provide sustained pain relief in PHN and warrant further evaluation in larger confirmatory studies.

References: N/A

Presenting Author: Nadine Attal
Submitting Author: Nadine Attal

Senior Author: Nadine Attal

IASP 2026 Global Year theme of Neuropathic Pain: Yes

• Ilona Bicker - Merz Therapeutics GmbH, Frankfurt am Main, Germany
• Irena Pulte - Merz Therapeutics GmbH, Frankfurt am Main, Germany
• Ralf Baron - University Hospital Schleswig-Holstein, Kiel, Germany
• Gudrun Klein - Merz Therapeutics GmbH, Frankfurt am Main, Germany
• Nanna B. Finnerup - Aarhus University, Aarhus, Denmark
• Thorin L. Geister - Merz Therapeutics GmbH, Frankfurt am Main, Germany
• Ullrich Munzel - Merz Therapeutics GmbH, Frankfurt am Main, Germany
• Eric Viel - Nîmes University Hospital and Montpellier-Nîmes Faculty of Medicine, Montpellier, France