The US Food and Drug Administration (FDA) has declined to approve Amneal Pharmaceuticals’ Parkinson’s disease treatment, with the regulator requesting additional safety data.
IPX203 is a new formulation of carbidopa-levodopa (CD/LD) – the standard of care for Parkinson’s disease – designed in a way that allows it to remain in the small intestine for a longer period, helping in its consistent absorption.
The company’s application was based on results from the phase 3 RISE-PD trial, which found that IPX203’s extended-release formulation offered significantly more ‘good on’ time, as well as significantly less ‘off’ time, compared to immediate-release CD/LD, even when dosed less frequently.
In a complete response letter, the FDA noted that although the company established the safety of levodopa, it was not able to adequately establish safety for carbidopa.
The letter did not identify any issues with respect to the efficacy or manufacturing of the drug, Amneal said, adding that it will be working with the FDA to address the comments.
Chirag and Chintu Patel, co-chief executive officers at Amneal, said: “We are committed to advancing IPX203 for Parkinson’s disease, which has been developed to provide a longer duration of therapeutic benefit than existing formulations with fewer doses.
“We plan to work closely with the FDA to address the agency’s feedback and we remain confident in bringing this new treatment to Parkinson’s patients as soon as possible.”
There is currently no cure for Parkinson’s disease, a progressive and chronic neurological disorder that affects an estimated one million people in the US alone – a number expected to rise to 1.2 million by 2030.
Amneal has another Parkinson’s drug approved in the US, Rytary, but only 4% of patients use it.
“Amneal aims to provide people living with Parkinson’s disease effective treatments that allow them to live their lives with less concern about their mobility and symptoms, and more freedom to choose how to spend their time,” said Gustavo Pesquin, the then chief commercial officer of Amneal Specialty, at the time of the original submission.
“We are pleased that IPX203 has the potential to address this need by extending periods when symptoms are better controlled, with less frequent dosing,” he added.