FDA Approves Carbidopa, Levodopa Extended Release for Parkinson Disease

Carbidopa and levodopa extended-release capsules are a novel, oral formulation that combine immediate-release granules and extended-release pellets.

Updated at 5:25 pm ET on August 7, 2024.

The FDA approved carbidopa and levodopa (CL/LD) (Crexont; Amenal) as extended-release capsules for the treatment of Parkinson disease. The novel, oral formulation combines immediate-release (IR) granules and extended-release pellets.¹

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“The approval of [carbidopa and levodopa] is a seminal moment in the treatment paradigm for Parkinson's disease,” Chirag and Chintu Patel, co-CEOs of Amneal, said in a news release.¹ "The burden of this incurable neurodegenerative disease increases with time. Some [Parkinson disease] patients on IR CD/LD take up to 10 daily doses and still experience motor fluctuations. [CL/LD's] innovative formulation provides a longer duration of 'Good On' time with less frequent dosing compared to IR CD/LD."

According to the press release, the existing oral CD/LD are short-acting products, which can cause patients to experiencing motor fluctuations and less daily “Good On” time, which is considered the “on” time for patients without dyskinesia plus “on” time with non-troublesome dyskinesia. This has become an indicator of successful motor symptoms control and is an emerging primary end point for Parkinson diseaes–related clinical trials, according to The Expert Institute for Parkinson’s Disease.^1,2

The drug has shown a statistically significant improvement of 0.5 hours of additional “Good On” time per day when compared with IR CD/LD and has an average of 3 times a day dosing compared with 5 times a day, respectively, according to results from the RISE-PD clinical trial (NCT03670953). RISE-PD was a 20-week randomized, double-blind phase 3 trial that was conducted across 105 academic and clinical centers in the US and Europe. Patients were screened by investigators from November 6, 2018, and June 15, 2021.³

About The Trial

Title: A Study to Evaluate the Safety and Efficacy of IPX203 in Parkinson's Disease Participants With Motor Fluctuations

ClinicalTrials.gov ID: NCT03670953

Sponsor: Impax Laboratories LLC

Completion Date: June 2021

The study consisted of a screening period that lasted up to 4 weeks, a 3-week open-label IR CD/LD dose-adjustment periods and a 4-week open-label ER CD/LD dose-conversion period. There was also a 12-week double-blind, double-dummy treatment period, according to the authors. Of 506 individuals who completed the open-label conversion, 88.7% completed the study.³

Investigators also found that the change from baseline in off-time hours per day showed that ER CD/LD resulted in significantly less off-time compared with IR CD/LD and 29.7% rated themselves much improved or very improved compared with 18.8%, respectively. In the double-blind period, 108 individuals on IR CD/LD experienced treatment-emergent adverse event (TEAEs) compared with 79 on ER CD/LD. Approximately 5.5% and 1.2% experienced TEAEs that resulted in discontinuation, respectively, and 3.1% and 1.6% experienced serious TEAEs, respectively.³

The most common TEAEs for ER CD/LD were nausea, anxiety, and dizziness compared with fall, urinary tract infection, and back pain for IR CD/LD.¹

“The treatment goals for people living with Parkinson disease include achieving a more robust duration of benefit per dose of LD, reducing ‘Off’ time, and simplifying dosing regimens," Robert A. Hauser, MD, professor of neurology at the University of South Florida and director of the Parkinson's Disease and Movement Disorders Center, said in the news release.¹ "[CL/LD’s] longer ‘Good On’ time per day and per dose represents a substantial advancement in managing motor symptoms and maintaining more consistent therapeutic effects, which is very encouraging for both patients and the Parkinson’s community."

References

1. Amneal receives US FDA approval for IPX203 for treatment of Parkinson’s disease to be launched as Crexont (carbidopa and levodopa) extended-release capsules. News release. Amneal. August 7, 2024. Accessed August 7, 2024. https://www.businesswire.com/news/home/20240807284173/en/Amneal-Receives-U.S.-FDA-Approval-for-IPX203-for-Treatment-of-Parkinson%E2%80%99s-Disease-to-Be-Launched-as-CREXONT%C2%AE-Carbidopa-and-Levodopa-Extended-Release-Capsules

2. Dewey RB, Pahwa R. The importance of “Good On” time and reducing dyskinesia. The Expert Institute for Parkinson’s Disease. 2022. Accessed August 7, 2024. https://pdexpertinstitute.com/wp-content/themes/eipd/docs/The%20Importance%20of-Good%20On-Time%20and%20Reducing%20Dyskinesia.pdf

3. Hauser RA, Espay AJ, Ellenbogen AL, et al. IPX203 vs immediate-release carbidopa-levodopa for the treatment of motor fluctuations in Parkinson disease: the RISE-PD randomized clinical trial. JAMA Neurol. 2023;80(10):1062–1069. doi:10.1001/jamaneurol.2023.2679