Does levodopa inhalation powder improve wearing-off time of patients with Parkinson’s disease?

This study investigated the effectiveness and safety of levodopa inhalation powder (CVT-301; Inbrija) in the treatment of wearing-OFF symptoms in patients with Parkinson's disease (PD). Researchers suggested that CVT-301 decreased the daily OFF time of these patients with manageable side effects.

Parkinson’s disease is a chronic disorder that affects 1% of the population over the age of 60. It affects the brain cells which are responsible for certain body functions. When these cells lose their abilities, the patient is left with symptoms such as tremors.

Levodopa is the standard treatment for patients with Parkinson’s disease. However, long-term use of levodopa is associated with wearing-OFF symptoms. This happens when the Parkinson’s symptoms are back, sometimes worse, before the next dose of levodopa. Overtime, levodopa is more readily taken in by the body, shortening ON times.

CVT-301 is a levodopa powder approved for the treatment of OFF episodes in patients previously treated with levodopa/carbidopa. It is administered through an inhaler in the mouth. It has been shown that the delivery of CVT-301 to the bloodstream is constant and reliable. Prior studies showed the 12-week effectiveness of CVT-301. However, too little is known about the long-term effectiveness and safety of this therapy.

This study included information about 312 patients receiving levodopa/carbidopa plus CVT-301. Patients received either 60 mg or 84 mg of CVT-301. Follow-up visits occurred every 3 months up to 12 months. Safety assessments included dyskinesia (uncontrolled body movements) and side effects. Other assessed outcomes were maintenance of improvement, change in daily OFF time, and patient impression of change.

Overall, 69.9% of patients reported at least one side effect related to the treatment. Most of these were mild. The most frequent side effects were cough (15.4%), fall (13.1%), respiratory infection (7.1%), and dyskinesia (5.1%). No significant changes were seen in lung function at 12 months.

At 12 months, 73% of patients on CVT-301 84 mg achieved an ON state within 60 minutes. The daily OFF time was reduced by 0.55 hours in the first month, and by 0.88 hours after 12 months. 65.5 to 91.9% of patients reported overall treatment satisfaction over 12 months. 

This study concluded that CVT-301 is associated with improved long-term outcomes in patients with Parkinson’s disease, with manageable side effects.

This study was funded by Acorda Therapeutics, the CVT-301 manufacturer.