IncobotulinumtoxinA Wins Pediatric Indication for Chronic Sialorrhea

Heakyung Kim, MD

Recently, the FDA accepted and approved a supplemental biologics license application (sBLA) for incobotulinumtoxinA (Xeomin; Merz Therapeutics) for the treatment of patients aged 2 years and older with chronic sialorrhea.

This indication marks incobotulinumtoxinA as the first and only FDA-approved neuromodulator available for this purpose, after it was previously granted a priority review designation upon sBLA filing acceptance by the FDA. The basis of the approval came from a phase 3 prospective, randomized, double-blind, placebo-controlled study that evaluated the efficacy and safety of incobotulinumtoxinA in 255 children and adolescents aged 2 to 17 years.

Results showed that the treatment significantly reduced unstimulated Salivary Flow Rate (uSFR), or the primary end point, compared with placebo at week 4 among patients aged 6 to 17 years, and sustained efficacy over 64 weeks. The study’s second primary end point, Global Impression of Change Scale (GICS) score, was also significantly improved and sustained over 64 weeks with the treatment compared with placebo. Notably, there were no observations of clinical resistance or secondary treatment failure due to neutralizing antibodies, which Merz noted supports the importance of the treatment’s unique purification process through XTRACT technology.

NeurologyLive inquired with Heakyung Kim, MD, A. David Gurewitsch Professor of Rehabilitation and Regenerative Medicine and Professor of Pediatrics, Columbia University Medical Center, to learn more about the potential impact of this approval.

NeurologyLive: How important is such an indication for this patient population?

Heakyung Kim, MD: I'm very happy to hear that incobotulinum toxin A (Xeomin) has been approved for the management of pediatric sialorrhea. Children with severe swallowing problems have significant problems with clearing their secretions which can lead to aspiration pneumonia, even though they are not fed by mouth. These patients frequently present to the emergency department and then require admission to the pediatric intensive care unit. These frequent hospital admissions lead to poor quality of life and a significant increase in health care costs.

How does it compare to the current standard of chronic sialorrhea management?

The current standard of care for sialorrhea is pharmacological management with anticholinergics such as glycopyrrolate or a scopolamine patch. However, these medications could cause significant side effects such as urinary retention, increased mucus plugging, and blurry vision. Therefore, botulinum toxin injection, including Xeomin, which he will be given locally, decreasing the risk of systemic side effects.

What should the clinical community know about this therapy regarding its mechanism of action and use, as it makes its way to market?

Generally, the mechanism of action of botulinum toxins is to block the transmission of acetylcholine at the neuromuscular junction. When used in the salivary glands, botulinum toxin such as Xeomin reduces the secretion of saliva by inhibiting cholinergic parasympathetic and postganglionic sympathetic activity.

Transcript edited for clarity.

REFERENCE
FDA Approves pediatric indication for Xeomin (incobotulinumtoxinA) for the treatment of chronic sialorrhea. News release. Merz. December 21, 2020. Accessed December 21, 2020. https://www.merzusa.com/news/pediatricsialorrhea/