Early Use of Gocovri Could Delay Levodopa-induced Dyskinesia: Study
The study, “Amantadine Treatment and Delayed Onset of Levodopa-Induced Dyskinesia in Patients with Early Parkinson’s Disease” was published in the European Journal of Neurology.
Levodopa and its derivatives are a mainstay of treatment for Parkinson’s disease. Although these medications are effective for controlling disease symptoms, they also cause side effects. Specifically, almost everyone treated with levodopa will eventually develop levodopa-induced dyskinesia, or LID, characterized by involuntary jerky movements.
Gocovri is approved to treat LID. This oral medication is also sometimes prescribed to help manage symptoms of early Parkinson’s, a practice generally more common in Asia than in Europe or America. Emerging evidence suggests that people with early-stage Parkinson’s who are treated with Gocovri may be less likely to develop LID, but this connection is poorly understood.
Scientists in Taiwan analyzed medical records of Parkinson’s patients at their hospital, identifying 798 early-stage patients who were treated with Gocovri. For comparison, 728 patients who had recently started on other treatments — specifically monoamine oxidase-B inhibitors (MAOBIs) or anticholinergic medicines — were included in the analysis.
The Gocovri group was older on average (69.46 vs. 62.4 years), and these patients tended to have more severe Parkinson’s and to be taking a higher equivalent dosage of levodopa (more than 400 mg of levodopa daily).
Patients were divided into three groups: those who had been treated with Gocovri or a comparator for at least six months, for at least a year, and those treated for at least 18 months. Statistical analyses were then conducted to calculate the risk of developing LID, with a median follow-up time of about three years in each group.
“To our knowledge, this is the first observational study that used longitudinal data to evaluate the effect of early amantadine [Gocovri] treatment on LID,” the scientists wrote.
Result showed that six months or one year of Gocovri treatment was associated with a significantly lower likelihood of developing levodopa-induced dyskinesia — by about 35% at both time points.
“Our results demonstrated that patients with early PD [Parkinson’s disease] who received amantadine treatment for at least 6 months had a significantly lower risk of LID than those who received either anticholinergics or MAOBIs for at least 6 months,” the team wrote.
Gocovri treatment for 18 months was also associated with a lower likelihood of LID onset, but the difference was not statistically significant. The researchers noted this finding may be because this group’s data covered fewer patients.
“We excluded patients with dyskinesia during the landmark periods; hence, the non-significant finding could have also resulted from the lower number of patients analyzed at the 18-month landmark point, which could have led to a loss of [statistical] power,” the researchers wrote.
Although this finding might also be due to Gocovri becoming less effective over time, “our clinical observations did not suggest that the effect of amantadine decreases over time,” the researchers wrote.
They stressed that more studies are needed to determine the optimal length of treatment with Gocovri to delay LID. They also noted a need for more research into the possible biological mechanisms underlying this effect, which remain poorly understood.
A limitation to this study is its single-center and retrospective nature, the researchers noted, adding that a “well-designed randomized controlled trial is required to validate our findings.”
Gocovri is marketed by Supernus Pharmaceuticals, which was not involved in this work.