Gocovri (amantadine) extended release capsules work to help lessen dyskinesia, or involuntary muscle movement, and off episodes in Parkinson’s, but special care needs to be given elderly patients with poorer kidney function, according to data presented by Adamas Pharmaceuticals, the treatment’s developer, at a science conference.
Renal insufficiency — or inadequate kidney function, often due to blood flow problems — can be common in people starting around age 70. Doctors should carefully monitor their kidney health and adjust Gocovri doses accordingly, the researchers said, to prevent amantadine from accumulating at unsafe levels in their system.
Gocovri is an extended release prescription medicine for dyskinesia, the sudden and uncontrolled movements that Parkinson’s patients experience on levodopa therapy, with or without use of other medicines working to increase the effects of dopamine — a chemical messenger— in the brain.
Although the therapy’s exact mechanism of action is not known, Gocovri has been shown to increase dopamine release and block its re-uptake, raising overall dopamine levels and easing motor symptoms.
Data from Gocovri’s development program and post-marketing surveillance were highlighted in five scientific posters at the International Congress of Parkinson’s Disease and Movement Disorders, running in France through Sept. 26.
In the study “The Effect of Gocovri on Motor Aspects of Experiences of Daily Living: Analyses of MDS-UPDRS Part II Data from a Phase 3 Program,” researchers assessed the impact of Gocovri capsules, taken at bedtime, on motor aspects of daily life in Parkinson’s patients.
Combined data from two Phase 3 trials (NCT02136914 and NCT02274766) found that 12 weeks of Gocovri treatment significantly improved motor skills and life activities in 82 treated patients, addressing such issues as freezing, tremor, eating, and getting out of bed/car/deep chair, compared to 87 patients given a placebo. According to the researchers, the improvement noted “was both statistically significant and clinically meaningful.”
In the study “Analysis of the Shape of the Gocovri Steady-state PK Profile: Implications for an Extended Release Product,” researchers detailed Gocovri’s pharmacokinetic profile — essentially, how the body affects a medicine.
Bedtime dosing of Gocovri resulted in a delayed, slow rise in amantadine concentrations. The analysis showed concentrations to be high in the morning and sustained throughout the day, but with minimal nighttime exposure, contributing to a sustained reduction in both dyskinesia and off episodes. (Off time refers to the periods when dopaminergic medication stops working, and motor symptoms reoccur.)
Three posters assessed the Gocovri’s safety. These assessments were made during the Phase 3 trials and throughout the year after the medicine was approved and made available to patients.
These posters are: “Gocovri Dose Adjustment in Elderly Parkinson’s Patients at Risk for Renal Impairment: Implications from an Exposure Simulation Model,” “The Efficacy and Safety of Gocovri Based on Age: Special Population Analyses of a Phase 3 Study Program” and “Safety of Gocovri in Clinical Practice: One-Year Post-Launch Pharmacovigilance Data.”
The most common side effects reported with Gocovri use are dizziness, hallucinations, and falls. While the treatment did ease dyskinesia and other motor complications in all age groups (under 65 to older than 75) studied, adverse events were more frequent in people age 75 and older.
Elderly patients are also more susceptible to renal impairment, the researchers noted in these posters, and may have evidence of chronic kidney disease (defined by researchers here as renal function of less 50 mL/min/m2). In these cases, doctors need to adjust Gocovri doses to avoid drug accumulation, resulting toxicity, and dose- and exposure-related side effects.
“No dose adjustment of Gocovri is recommended on the basis of age alone; however, because renal impairment is common in elderly patients, care should be taken in dose selection, and it may be useful to monitor renal function,” they wrote.
Gocovri extended release is available at two different doses, as 68.5 mg and 137 mg capsules.
Side effects seen in prescription use closely mirror those observed in the Phase 3 trials, the researcher noted, including reports of hallucinations.
“Adamas’ purpose is to significantly improve the lives of people affected by neurological diseases, and we remain committed to the presentation of Gocovri data to provide further information to support robust clinical discussions,” Rajiv Patni, MD, the company’s chief medical officer, said in a news release.
“Our goal is to ensure that neurologists understand how Gocovri may be an option for their Parkinson’s disease patients with dyskinesia on dopaminergic therapies by providing them with a treatment that may increase functional on time by decreasing both dyskinesia and off,” Patni added.