Acadia Pharmaceuticals recently released the results of their Phase 3 trial of Nuplazid, a treatment for the psychosis that Parkinson’s disease patients experience. This medication has been approved since 2016, but its long-term affects were still unknown. Understanding them was the purpose of this trial. The results were presented at the virtual 2020 American Society of Clinical Psychopharmacology (ASCP) Annual Meeting, and you can read about them here.
About Parkinson’s Disease
Parkinson’s disease is a progressive disorder that affects the central nervous system (CNS). It is characterized by its effect on movement through five different stages. As the disease progresses, severity increases. Stage one is characterized by subtle tremors on one side of the body. In stage two symptoms are more noticeable, with tremors and rigidity on both sides of the body. Stage three brings loss of balance and slow movement, while stage four makes it impossible for one to live independently. Stage five is the most severe, as patients cannot stand or walk. Hallucinations and delusions are common symptoms of this stage.
Parkinson’s disease occurs due to the death of motor neurons, some of which produce dopamine. Dopamine is important in the transmittance of messages to the muscles from the brain, so the loss of dopamine results in the loss of motor functions. Abnormal brain activity occurs when these neurons are lost. Doctors do not know why these motor neurons die, but they do suspect a few factors that play a role, such as genetics, environmental factors like toxins, and Lewy bodies.
There are no FDA approved therapies for Parkinson’s, and treatment is symptomatic. Treatment options include dopamine substitutes, carbidopa-levodopa, MAO-B inhibitors, catechol-O-methyltransferase (COMT) inhibitors, anticholinergics, and amantadine.
About the Study
Nuplazid was developed by Acadia Pharmaceuticals and approved by the FDA in 2016. It is intended to treat psychosis, which is a symptom of Parkinson’s disease. It does so by blocking signals to and from certain serotonin receptors.
While this medication has already been approved and studied in a number of clinical trials, medical professionals did not know enough about its safety and tolerability in the long run. Because of this, Acadia began an extension trial that included 459 patients who had participated in prior trials. All participants were given Nuplazid orally every day for the past ten years. They were evaluated on a set schedule for the past decade to measure this treatment’s safety and tolerability.
The study found that the majority (85.4%) of participants experienced an adverse effect, which were typically mild to moderate. Serious adverse effects, including UTIs, pneumonia, and hip fracture, were reported in 41% of participants. Because of adverse effects, 29% decided to stop their treatment.
In terms of symptom severity, this study discovered that the effects of Parkinson’s remained stable over time. Researchers used the Clinical Global Impression scale to evaluate this. On the other hand, caregiver burden scores did increase by 4.3 over 192 weeks.
The researchers working on this study do acknowledge that there were limitations, as there was no control group, and they could not follow patients who chose to discontinue treatment; but they still feel that this study proves that Nuplazid is safe and well-tolerated.