The company, a unit of Germany’s Merz Pharma, will present results from the SIAXI Phase 3 clinical trial (NCT02091739) June 7 at the 21st International Congress of Parkinson’s Disease and Movement Disorders now underway in Vancouver.
“The breadth of data to be presented is encouraging and provides valuable information to the scientific and medical communities,” Bob Rhatigan, president and CEO of Merz North America, said in a press release. “The results will deepen understanding of the complexities of treating, and the challenges of living with, neurological disorders.”
Lead author Andrew Blitzer and his colleagues conducted the largest-ever controlled study of Xeomin to treat sialorrhea, or excessive drooling. This disabling symptom occurs in 50 to 80 percent of all Parkinson’s patients — especially men — and can lead to social isolation, embarrassment and other consequences.
The subjects selected for their study, “SIAXI: Efficacy and safety of incobotulinumtoxinA for the treatment of sialorrhea in Parkinson’s disease (PD) and other neurological conditions: Results of a Phase III, placebo-controlled, randomized, double-blind study,” were adults with chronic, troublesome drooling due to Parkinson’s, stroke or traumatic brain injury.
Participants were randomly assigned in a double-blind fashion to receive either 75U or 100U incobotulinumtoxinA or placebo, and followed for 16±2 weeks after treatment.
Researchers evaluated the efficacy of the two doses of incobotulinumtoxinA at week four after injection, using as primary endpoints the unstimulated Salivary Flow Rate (uSFR) and Global Impression of Change Scale (GICS) and comparing to baseline. They also measured other secondary outcomes such as Drooling Severity and Frequency Scale (DSFS) and modified Radboud Oral Motor Inventory in Parkinson’s Disease (mROMP) drooling.
The researchers found that the 75U dose was more effective than placebo, but with no statistical significance difference at week four. At week eight and 12 after treatment, patients showed significant improvement in both uSFR and GICS, with constant progress in the uSFR in both dose groups at the last observation point at week 16. Secondary analyses (DSFS and mROMP drooling) confirmed the effectiveness of both treatment regimens.
These observations provided robust and consistent evidence that Xeomin improves sialorrhea in Parkinson’s patients, said the company. Importantly, no safety signals were identified during the study. In fact, it said, the 100U dose provided better results with no additional side effects.