Application of Parkinson’s therapy IPX203 resubmitted to FDA

Agency sought more information on treatment's safety in July 2023

Margarida Maia, PhD avatar

by Margarida Maia, PhD |

Share this article:

Share article via email
A bell with the word

Amneal Pharmaceuticals has resubmitted its application for IPX203, an investigational extended-release oral formulation of carbidopa and levodopa for treating Parkinson’s disease.

The move follows a request by the U.S. Food and Drug Administration (FDA) in July 2023 for more information on the safety of IPX203’s carbidopa component before a final decision is made. The resubmission included data from a study in healthy volunteers conducted late last year. The FDA hadn’t asked for additional data.

“We are pleased to provide our complete response resubmission for IPX203 as we look to expand our Parkinson’s franchise,” Chirag and Chintu Patel, Amneal’s CEOs, said in a press release. “We look forward to launching this much-needed treatment in the second half of 2024, subject to FDA approval.”

Parkinson’s is caused by the progressive loss of dopamine, a chemical messenger that transmits information from one nerve cell to another, in an area of the brain responsible for planning and controlling body movements.

Recommended Reading
A scientist is shown using a laser that points to a large rendering of the words

Knight gains rights to IPX203, for off times, in Canada and Latin America

Steady carbidopa, levodopa levels aim of IPX203

The mainstay of Parkinson’s treatment is levodopa, a molecule cells use to make dopamine. It’s often given with carbidopa, which stops cells outside the brain from diverting levodopa, letting more of it reach the brain where it can ease Parkinson’s symptoms.

Levodopa may begin to lose its effect with long-term use, however. As a result, patients may have off episodes, when levodopa wears off between doses and dyskinesia (uncontrolled, involuntary movements) and other symptoms return.

IPX203 is designed to maintain steady levels of carbidopa and levodopa in the body. It contains rapidly dissolving granules of carbidopa and levodopa along with extended-release beads coated with a polymer (large molecule) that allows for a slow release of levodopa.

The formulation differs from that of Rytary, Amneal’s approved capsules that are designed to immediately release a given amount of carbidopa and levodopa when its administered and continue releasing them slowly for several more hours.

The application of IPX203 was based on topline data from RISE-PD (NCT03670953), a Phase 3 clinical trial in 506 adults with advanced Parkinson’s where IPX203 was better than immediate-release tablets of carbidopa and levodopa at prolonging daily time without dyskinesia.

IPX-203 three times daily still offered more benefits than immediate-release tablets taken five times a day. A post hoc analysis showed each dose of IPX-203 reduced the average duration of off episodes by about 1.5 hours compared with the immediate release tablets.