The U.S. Food and Drug Administration (FDA) has approved tavapadon, a once-daily oral medication for the treatment of motor symptoms of Parkinson’s disease.
Tavapadon, which will be sold under the brand name Juvmo, is a new drug in an existing class of Parkinson’s drugs: dopamine agonists. These medications act like dopamine, the brain chemical that decreases in Parkinson’s and causes movement symptoms such as slowness, stiffness and tremor. Dopamine agonists can reduce motor symptoms, but they can have side effects that can be difficult for some to tolerate. Because tavapadon works differently than previous dopamine agonists, it could cause fewer side effects.
In clinical trials, tavapadon improved movement symptoms in people with both recently diagnosed and progressing Parkinson’s, either on its own or in addition to levodopa, respectively.
“People with Parkinson’s need more than one path to symptom control,” said Rachel Dolhun, MD, DipABLM, principal medical advisor at The Michael J. Fox Foundation. “Every new treatment expands what people and their doctors can consider, increasing the chances of finding an approach that fits each person’s symptoms, priorities and daily life.”
Read on to learn more about tavapadon, the clinical trial results that led to approval and what this new treatment may mean for you.
How Does Tavapadon Work?
Dopamine agonists work by mimicking dopamine. Rather than replacing the missing chemical, like levodopa does, these drugs instead do the work of dopamine. They attach to dopamine’s docking sites (receptors) on brain cells and switch them on much as dopamine would.
Previously approved dopamine agonists attach to receptors in brain circuits both for movement and for reward and alertness. So they ease motor symptoms but also can cause side effects that include daytime sleepiness, sudden sleep attacks, hallucinations and impulse control disorders, which are hard-to-resist urges that lead to behaviors like excessive shopping or eating or increased increase in sex.
Tavapadon works differently, targeting only the brain circuit for movement. Because of this, tavapadon may ease motor symptoms with lower rates of the side effects that have limited earlier dopamine agonists. However, tavapadon has not been directly tested against other dopamine agonists and trials may have been too short to demonstrate the full amount and extent of the drug’s potential side effects.
An ongoing study (TEMPO-4) is designed to gather data beyond the clinical trials to better understand tavapadon’s longer-term safety, side effects and benefits.
Tavapadon is a once-daily pill. Other approved dopamine agonists come in various forms — pills, a skin patch, an as-needed injection and a pump that delivers medication continuously under the skin. Some are taken multiple times per day; others once daily. All dopamine agonists, including tavapadon, can be taken on their own or along with levodopa and other Parkinson’s medications.
What Did the Clinical Trials Show?
Tavapadon approval was supported by the TEMPO clinical trials, a series of Phase III studies that evaluated the drug in people at different points in Parkinson’s.
The TEMPO-1 and TEMPO-2 trials studied the drug in people with earlier Parkinson’s who were within three years of diagnosis and not on dopamine medication, like levodopa. Compared to placebo, tavapadon improved motor symptoms such as tremor, stiffness and slowness and ability to do daily activities, including dressing, eating and caring for personal hygiene.
The TEMPO-3 trial studied the drug in people already taking levodopa who experienced “off” time, when symptoms return between doses, or dyskinesia (involuntary movements). Adding tavapadon provided an average of about one additional hour of daily “on” time, when symptoms are well-controlled, without dyskinesia. It also reduced “off” time by about an hour per day.
Across the clinical trials, tavapadon was generally well tolerated. The most common side effects were nausea, headache and dizziness. In people with progressing Parkinson’s who took tavapadon in addition to levodopa, side effects also included dyskinesia, orthostatic hypotension (low blood pressure on standing) and hallucinations. Impulse control disorders, daytime sleepiness and hallucinations seemed to happen at less frequent rates than what’s reported with older dopamine agonists but were slightly increased in people with progressing disease compared to people with earlier disease.
MJFF Adds Perspective of Patients to Economic Review
As part of The Michael J. Fox Foundation’s (MJFF’s) growing work to help move new treatments from approval to access, the Foundation weighed in on a review of tavapadon by the Institute for Clinical and Economic Review (ICER). ICER is an independent nonprofit that assesses the value of treatments. Its findings can influence how insurers approach coverage, although ICER does not make coverage decisions. This was ICER’s first review of a Parkinson’s treatment and its formal recommendations are expected in the coming weeks.
MJFF joined other Parkinson’s organizations, people with Parkinson’s and care partners to help ensure the ICER review reflected what treatment benefits can mean in everyday life, including greater independence, improved daily function, fewer non-motor symptoms, less unpredictable “off” time and reduced impact on care partners. Highlighting these factors helped ensure that the assessment considered the treatment’s full potential value, beyond changes measured in clinical trials. The review also highlighted a broader field-wide challenge: Available evidence does not always connect changes measured in clinical trials with quality of life, care needs and impacts on families. Addressing these gaps can help future assessments and may ensure coverage decisions more fully reflect the value treatments may bring to people with Parkinson’s and their families.
What Does Tavapadon Mean for People with Parkinson’s?
Tavapadon, manufactured by AbbVie, adds another option for treating Parkinson’s motor symptoms, both for people who are recently diagnosed and for those who having been living with Parkinson’s for some time.
“While new drug approvals signal important research progress, newer doesn’t always mean better for each individual,” says Dr. Dolhun. “If your medication regimen is working, you may not need to make any changes. But if not, and if you’re interested in tavapadon, speak with your personal Parkinson’s care team.”
Tavapadon should be available by prescription within the coming months, though insurance coverage may take longer to fall into place.