The FDA had issued a complete response letter (CRL) in July 2023 for IPX203 and asked for additional pharmacokinetic data of carbidopa, one of the drugs the oral, extended release therapy.
Amneal has resubmitted its application for an oral formulation of carbidopa/levodopa (CD/LD) extended-release capsules for the treatment of Parkinson’s disease. The FDA had issued a complete response letter (CRL) in July 2023 for IPX203. The FDA had asked for additional pharmacokinetic data of carbidopa, one of the drugs in IPX203. Pharmacokinetic data provides information about how the drug is adsorbed, distributed, metabolized and excreted from the body.
The FDA’s CRL for IPX203 indicated that although an adequate scientific bridge was established for the safety of one ingredient, levodopa, based on pharmacokinetic studies, it was not adequately established for carbidopa. The letter did not identify any issues with respect to the efficacy or manufacturing of IPX203.
About 1 million patients diagnosed with Parkinson’s disease in the United States. It is a progressive disorder of the central nervous system that affects dopamine-producing neurons in the brain that affect movement.
IPX203 contains extended-release beads that consist of levodopa, coated with a sustained release polymer, to allow for slow release of the drug. Additionally, this formulation contains immediate-release granules that consist of carbidopa and levodopa, with a disintegrant polymer to allow for rapid dissolution. This formulation of IPX203 is different from Rytary extended-release capsules, Amneal’s extended-release carbidopa/levodopa treatment for Parkinson’s disease that the FDA approved in 2015.
The NDA submission is based on the results from the phase 3 RISE-PD clinical trial, which found that IPX203’s extended-release formulation offers significantly more “Good On” time. The trial also showed this was the case when IPX203 was dosed on average three times per day and immediate-release carbidopa/levodopa was dosed on average five times per day. The trial also showed that subjects on IPX203 demonstrated significantly less “Off” time compared with immediate-release carbidopa/levodopa.