Phase 2 trial of VG081821 to ease motor symptoms fully enrolled
150 patients being given low or high dose treatment or placebo for 12 weeks
Enrollment is complete in a Phase 2 trial of VG081821, an investigational therapy to treat early to mid-stage Parkinson’s disease, the therapy’s developer, Vimgreen, announced.
A total of 150 patients have been randomized to receive a low or high dose of VG081821 or a placebo for 12 weeks, or about six months. The trial will assess the treatment’s safety and efficacy in easing disease motor symptoms and is expected to be completed in November, the company, based in Hangzhou, China, stated in a press release.
Parkinson’s is caused by the progressive dysfunction and death of dopaminergic neurons, nerve cells responsible for producing dopamine, a brain neurotransmitter (chemical messenger) essential for motor control. This leads to a characteristic set of disease motor symptoms, including slowed movements, muscle rigidity, and tremors, as well as Parkinson’s nonmotor symptoms.
Therapy designed to block the adenosine A2A receptor and lower its activity
Currently available disease therapies mainly work to replace dopamine so as to increase its levels, such as levodopa, the precursor of dopamine; monoamine oxidase-B inhibitors, which reduce the breakdown of dopamine in the brain; and COMT inhibitors that block an enzyme which deactivates levodopa, improving its action.
Another group of medicines, dopamine agonists, mimic dopamine activity in the brain.
While these therapies work to ease symptoms, they are unable to slow disease progression. Moreover, long-term use of levodopa is associated with off episodes, periods between doses when symptoms are not fully controlled, and with dyskinesia, the sudden and uncontrolled movements that commonly affect patients.
VG081821, also called VG081821AC, is an antagonist of the adenosine A2A receptor (A2AR), a type of receptor that regulates adenosine, another neurotransmitter involved in the regulation of movement. An antagonist is a molecule that binds to a receptor and prevents it from being activated.
VG081821 also is reported to work as an inverse A2AR agonist. This means that instead of just blocking the receptor, like an antagonist does, it lowers its activity level.
“More than a classical A2A antagonist, VG081821 may have extra therapeutic effect and greater efficacy on motor dysfunction,” the company stated in its release.
As such, Vimgreen expects that the treatment will both ease Parkinson’s motor symptoms and decrease, delay, or prevent the motor complications associated with long-term levodopa use and other medications.
Trial’s main goal is an easing in motor symptoms with treatment
“VG081821 is to be used as monotherapy for improving movements in early-to-mid stage of PD [Parkinson’s disease]. Later on, as the disease progresses, it can be used in combination with low doses of L-Dopa [levodopa],” said Sanxing Sun, Vimgreen’s president and CEO. “This L-dopa sparing effect may minimize the problem of L-Dopa and prolong the quality of life of PD patients.”
The trial’s main goal is to assess changes in motor symptoms compared with baseline measures (those treatment initiation), using part three of the Movement Disorder Society-Unified Parkinson’s Disease Rating Scale. Scientists also will evaluate changes in A2AR levels in circulating blood, because A2AR gene expression, or activity, is known to be high in patients’ blood cells.
Measuring changes in a patient’s A2AR expression levels with treatment could help doctors determine whether VG081821 might be a personalized, or precision, medicine for that person, the company stated.
More information on the Phase 2 trial, including where it is taking place and how the treatment is administered, was not available.
About the Author
