Amneal lines up FDA Parkinson's filing as pivotal data roll in

Brain image from Parkinson's study
A brain image from a Parkinson's study (Radiological Society of North America)

Amneal Pharmaceuticals has teed up an attack on the Parkinson’s disease market. With phase 3 data on IPX-203 now in, Amneal is gearing up for a filing for FDA approval of a drug it thinks can unlock the carbidopa/levodopa market.

IPX-203 consists of carbidopa/levodopa granules, in both immediate-release and extended-release forms, and mucoadhesive polymers. Amneal tested the formulation, which is distinct from its Rytary extended-release product, in a phase 3 clinical trial. 

After a seven-week open-label period, investigators randomized 631 Parkinson's patients with motor fluctuations to receive IPX-203 or immediate-release carbidopa/levodopa for 13 weeks. Across the 20-week study, mean "On" time without troublesome dyskinesia in the IPX-203 group increased from 9.46 hours to 11.35 hours. The rise in the control group was smaller, and the 0.53-hour difference was big enough for the study to hit its primary endpoint.

Amneal also linked IPX-203 to reduced "Off" time and positive results on a patient-reported outcome. Almost 30% of patients on IPX-203 said they felt at least “much improved,” compared to 19% of their peers on immediate-release carbidopa/levodopa. However, IPX-203 was no better than the control in terms of scores on the MDS-UPDRS Parkinson’s disease rating scale. 

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With IPX-203 outperforming control in some areas despite being dosed less frequently, Amneal plans to file for FDA approval around the middle of next year. Winning approval would set Amneal to try to go after a larger slice of the Parkinson’s market. 

Amneal’s extended-release carbidopa/levodopa formulation Rytary won FDA approval in 2015 but is a niche product. Rytary sales in the first half of the year totaled $80 million, and Amneal calculates it represents around 5% penetration into the broader carbidopa/levodopa market.  

Ahead of the planned filing for approval, Amneal has begun to consider what it will take to make a commercial success of IPX-203. The planned strategy diverges from how Amneal has approached the task in the past, with a greater emphasis on engagement of key opinion leaders, formulary coverage, patient support services and dose conversion education.