Merz North America has announced that the US Food and Drug Administration (FDA) has accepted its Biologics License Application (sBLA) for Xeomin (incobotulinumtoxinA) as a treatment for chronic sialorrhea.

The FDA has set a Prescription Drug User Fee Act (PDUFA) action date in the fourth quarter of 2018. If approved, Xeomin has the potential to be the first neurotoxin with this indication in the US.

Chronic sialorrhea results from neurologic disorders such as Parkinson’s Disease and is characterised by excessive drooling.

“Sialorrhea is a common problem among people living with neurological disorders, causing added physical and psychosocial challenges for patients as well as caregivers,” Merz North America vice president David Dobrowski said.

“We believe Xeomin can help manage excessive drooling, and we look forward to continuing to work closely with the FDA as they review our application.”

The application is based on a Phase III study conducted last year which met both of its co-primary endpoints, achieving statistically significant change in both unstimulated salivary flow rate (uSFR) and in the subjects’ Global Impression of Change Scale (GICS).

The trial enrolled 184 patients who were administered with incobotulinumtoxinA dosed at either 100 U or 75 U, or placebo over a 16-week period.

A statistically significant improvement was observed in uSFR at week four as compared with baseline pre-injection, while the change in GICS was also observed at week four. The most common side-effects included tiredness, headache, muscle weakness and dry mouth. However, overall frequency of adverse events was similar between placebo and treatment groups with no new or unexpected adverse effects reported.

“Drooling is a burden to both patients and their caregivers,” the study’s coordinating investigator Dr Andrew Blitzer said.

“Importantly, the study results demonstrate a duration of efficacy and benefit beyond four months after the initial injection.”

Results of the study were presented at the 2017 International Congress of Parkinson’s Disease and Movement Disorders, American Academy of Physical Medicine and Rehabilitation and American Congress of Rehabilitation Medicine annual meetings.

Xeomin is a neuromuscular blocker that is already approved to treat muscle stiffness in patients with upper limb spasticity, cervical dystonia in both botulinum toxin-naïve and previously treated adult patients, blepharospasm in adults previously treated with onabotulinumtoxinA, and for the temporary improvement in the appearance of moderate-to-severe glabellar lines associated with corrugator and/or procerus muscle activity.