Acorda Announces Positive Phase 3 Clinical Trial Results for CVT-301 showing a statistically significant improvement in motor function in people with Parkinson’s disease experiencing OFF periods. CVT-301 is an investigational, inhalable formulation of levodopa (L-dopa). It is being studied as a treatment for OFF periods in people with Parkinson’s disease taking an oral carbidopa / levodopa regimen. OFF periods refer to the re-emergence of Parkinson’s symptoms.