The inhaled INBRIJA therapy is indicated to treat 'off' episodes in patients taking carbidopa/levodopa.
A new Parkinson disease (PD) therapy received regulatory approval 2 weeks prior to its deadline—and within hours of the government shutdown preventing it from happening.
The US Food and Drug Administration (FDA) approved levodopa inhalation powder (INBRIJA) as a first-of-its-kind intermittent therapy for ‘off’ episodes in patients with PD currently being treated with carbidopa/levodopa. Drug maker Acorda Therapeutics received word of its approval on the evening of December 21—just prior to the government shutdown taking place at midnight.
Following the announced approval on the morning of the 22nd, Chris Kenney, MD, senior vice president of Medical Affairs for Acorda, called the FDA decision in the scope of the impeding shutdown “incredible timing,” and one that which puts the company in a unique position of offered therapies going into 2019.
Among the approximate 1 million people in the US with PD, about 40% experience off periods. The limited market for therapies offering capability to shorten or improve off periods is generally comprised of drugs that influence patients’ gastroenterological systems. The powder is the first to be delivered through inhalation, and has been showed to provide benefit in as soon as 10 minutes.
“You’re treating a disorder of the central nervous system through the pulmonary system,” Kenney said. “This is very rare.”
The therapy’s approval was backed by the phase 3 pivotal efficacy trial SPANSM-PD—a 12-week, randomized, placebo-controlled, double blind study in which patients with mild to moderate PD who experience off periods were treated with either inhaled levodopa or placebo.
Patients administered 84 mg of the investigative therapy (n= 114) reported statistically significant motor function improvement in week 12 versus those given placebo (n= 112), as measured by reduced scores in the Unified Parkinson’s Disease Rating Scale (UPDRS) Part III score. At the 30-minute post-dose mark, they reported a mean UPDRS score reduction of 9.83 points, versus 5.91 for those on placebo (P = .009). Investigators reported an action onset as early as 10 minutes following administration.
Common adverse reactions in patients treated with levodopa inhalation included cough (15%), upper respiratory tract infection (6%), nausea (5%), and discolored sputum (5%). In another phase 3, long-term trial assessing its safety and tolerability in 398 patients over 1 year of care, treated patients reported similar reductions in forced expiratory volume in 1 second (FEV1) as those in observational cohorts (-0.1 L). The trial excluded patients with asthma, chronic obstructive pulmonary disease (COPD), or other chronic respiratory disease within the last 5 years.
Kenney called the development and eventual approval of an inhaled, tolerable therapy for PD off episodes a venture that spanned 20 years—from early work in the lab of Massachusetts Institute of Technology (MIT) professor Dr. Robert Langer, to the present day approval. He cited the adage “it takes a village” when describing the process of progressing a new therapy for PD.
“There were massive amounts of resources that went into this, and it’s the culmination of 20 years of work,” Kenney said. “We’re just excited to be here at this point of time.”
INBRIJA is anticipated to become commercially available in Q1 2019, and Kenney said expects there to be phase 4 trials and consideration towards other indications for the drug, but such plans have not yet been made.