The US Food and Drug Administration has approved levodopa inhalation powder (Inbrija, Acorda Therapeutics) for intermittent treatment of "off" episodes in people with Parkinson's disease who are already taking an oral carbidopa-levodopa regimen.

"Despite being on treatment, patients may experience 'off' periods as Parkinson's progresses, which can be disruptive," Todd Sherer, PhD, CEO, the Michael J. Fox Foundation, said in a company news release.

"The Foundation provided funding for the early clinical development of Inbrija because patients told us that 'off' periods were one of their most serious issues. We knew we had to help address this unmet need, and this approval is a significant step forward for the community, as it provides a new option to manage these gaps in symptom control," said Sherer.

The efficacy of levodopa inhalation powder was demonstrated in the randomized, double-blind, placebo-controlled, phase 3 SPAN-PD trial of patients with mild to moderate Parkinson's who experienced "off" periods while taking carbidopa-levodopa.

The trial met its primary endpoint, with patients using levodopa inhalation showing statistically significant improvement in motor function at the week 12 visit, as indicated by a reduction in Unified Parkinson's Disease Rating Scale Part III (UPDRS III) score, compared to those taking placebo.

The change at week 12 in UPDRS III score was –9.83 for patients receiving the 84-mg dose vs –5.91 for the group taking placebo (P = .009). Onset of action was seen as early as 10 minutes.

The most common adverse reactions with inhaled levodopa were cough, upper respiratory tract infection, nausea, and discolored sputum.

Inhaled levodopa was also investigated in a phase 3 long-term, active-controlled, randomized, open-label study that assessed safety and tolerability over 12 months. In this study, the average reduction in forced expiratory volume in 1 second from baseline was the same (-0.1 L) for the inhaled levodopa and observational cohorts.

The study excluded patients who had been diagnosed with chronic obstructive pulmonary disease, asthma, or other chronic respiratory disease within the past 5 years.

Inbrija is expected to be available by prescription in the United States in the first quarter of 2019 and will be distributed through a network of specialty pharmacies.

Full prescribing information is available online.

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