SAN DIEGO — Inhaled levodopa (CVT-301) can reduce the amount of “off” time per day for patients with Parkinson’s disease on an oral levodopa/dopamine-decarboxylase inhibitor regimen, according to a study presented at the International Parkinson and Movement Disorder Society (MDS) 19th International Congress in San Diego, Calif.
Levodopa is the most effective oral treatment for Parkinson motor symptoms. However, irregular intestinal absorption causes approximately half of patients treated with the drug to experience “off” episodes where the drug does not help with motor improvement. The researchers wanted to determine if inhaled levodopa could remedy the delayed and/or unreliable onset of the drug’s effects.
The study included 86 patients with Parkinson’s disease who experienced at least two hours of “off” time per day. They were randomly assigned to either CVT-301 or placebo in addition to their oral levodopa/dopamine-decarboxylase inhibitor regimen. Each participant was told to self-administer the drug as needed for “off” states up to three times per day over a four-week period. During the first two weeks, participants took 35mg of inhaled levodopa with each administration. This was increased to 50mg for weeks three and four.
Participants in the CVT-301 and placebo groups were matched for age, gender, duration of disease, duration of “off” episodes, Parkinson’s disease drug use, and Unified Parkinson’s Disease Rating Scale (UPDRS) Part III scores during “on” and “off” times.
The researchers assessed each patient with the UPDRS Part III in 10-minute intervals after drug or placebo administration, from 0 to 60 minutes. Participants taking CVT-301 showed improvement at all 10-minute intervals beginning at 10 minutes after administration compared with those taking placebo. These improvements over placebo were present both with 35mg and 50mg of levodopa.
The results indicated that the 35mg dose of levodopa reduced “off” duration by an average of 1.1 hours per day. The 50mg dose significantly reduced the duration by an average of 1.6 hours per day.
Additionally, the researchers did not find any differences in “on” time with dyskinesia with CVT-301 at any point compared with placebo. The medication was safe and well tolerated.
The researchers believe that CVT-301 could be a comparator for apomorphine (Apokyn) injections. They suggest a crossover study in order to determine if one of the treatments is more effective than the other.