As multiple drugmakers race to bring novel, levodopa-based Parkinson’s disease treatments to the market, New Jersey’s Amneal Pharmaceuticals has taken home the gold in the U.S.
Late Wednesday, the FDA granted approval to Amneal’s Crexont—formerly known as IPX203—which is an oral, extended-release formulation of the common Parkinson’s drugs carbidopa/levodopa (CD/LD).
The capsule, which contains a mix of immediate-release CD/LD granules and extended-release LD-coated beads, is expected to launch in the U.S. in September, Amneal said in a release.
Crexont is designed to deliver more “good on” time for Parkinson’s patients with less frequent dosing versus immediate-release CD/LD. Essentially, the goal of the medication is to boost the duration of therapeutic benefit over existing formulations with fewer doses.
Those short-acting, oral formulations of CD/LD make up more than 90% of current Parkinson’s prescriptions, according to an Amneal spokesperson. Some patients end up taking these immediate-release formulations up to 10 times a day and still experience motor fluctuations from their disease, she added.
The FDA based its approval on Amneal’s late-stage RISE-PD study, in which Crexont offered statistically significant improvement of 30 minutes additional “good on” time per day compared to immediate-release CD/LD. On average, patients on Crexont took three doses a day versus five for those on short-acting Parkinson’s formulations.
Further, in a post hoc analysis, Crexont was seen to give patients another 1.6 hours of “good on” time per dose, boosting patients’ improved daily function by 4.8 hours compared to instant-release CD/LD.
Amneal defines “good on” time as “on” time without dyskinesia, or involuntary muscle movements.
“The approval of Crexont is a seminal moment in the treatment paradigm for Parkinson’s disease,” Amneal’s co-CEOs, Chirag Patel and Chintu Patel, said in a statement. “Amneal is so excited to introduce this meaningful new treatment for Parkinson’s patients in the U.S. and soon internationally.”
There are roughly 1 million people with Parkinson’s living in the U.S. and approximately 90,000 new cases diagnosed each year, according to Amneal.
The company has clinched an approval after the FDA rejected Crexont last summer, citing inadequate safety data on the drug’s CD component, which demanded additional pharmacokinetic information. At the time, the company said it was targeting peak U.S. annual net sales of Crexont between $300 million and $500 million.
Amneal has been counting on the approval of Crexont to maintain its competitive edge in Parkinson’s, where the company’s marketed med Rytary is expected to lose patent protection in 2028.
The pharma is, however, far from the only company to run up against regulatory hurdles while developing novel formulations of levodopa.
In June, for instance, the FDA rejected AbbVie’s ABBV-951—a more convenient successor to the company’s established Parkinson’s med Duopa—for controlling motor fluctuations in patients with advanced Parkinson’s. The snub hinged on observations made by the regulator during an inspection of a third-party manufacturer listed in AbbVie’s drug application.
AbbVie’s prospective therapy is a combination of foscarbidopa and foslevodopa, which are the respective prodrugs for the carbidopa and levodopa included in AbbVie’s 2015-approved Parkinson’s treatment Duopa. Prodrugs are versions of medications that become active once they enter the body.
Also in June, NeuroDerm was hit with a complete response letter on its application for ND0612, which is a 24-hour subcutaneous infusion of liquid LD/CD.