Following the news that Amneal Pharmaceuticals received a complete response letter (CRL) from the FDA, concerning its new drug application for IPX203 (carbidopa/levodopa) as a treatment for Parkinson’s disease (PD); Christie Wong, Neurology Analyst at GlobalData, a leading data and analytics company, offers her view:
“Although levodopa has been the gold standard for patients with PD for over 50 years, occurrences of peak-dose dyskinesia and off-episodes are common motor complications that are caused by intermittent dopaminergic stimulation. Amneal’s IPX203 is an oral extended-release (ER) capsule formulation of levodopa that is designed to sustain levodopa plasma concentrations and control motor fluctuations in PD patients.
“IPX203 consists of immediate-release (IR) granules of carbidopa/levodopa and ER beads of levodopa. It is common for levodopa-based therapies to be formulated in combination with carbidopa to ensure that adequate concentrations of levodopa reach the central nervous system. However, the FDA has requested additional safety information for the carbidopa present within the IR granules, which contain disintegrant polymer to allow for rapid dissolution. Although the drugs are common in PD, the formulation is just novel enough to require further due diligence by the agency.
“The patent expiry of Amneal’s Rytary, an oral ER capsule formulation of levodopa, is anticipated in 2028, which will inevitably shrink its sales. But should IPX203 receive regulatory approval could help maintain Amneal’s presence in the PD market.
“However, some key opinion leaders (KOLs) previously interviewed by GlobalData indicated that the improvement in efficacy with IPX203 compared with IR formulations of levodopa was not significant to impact their treatment patterns, particularly if IPX203 is anticipated to have premium pricing. But IPX203 could be an option for patients who have not had a good experience with Rytary, as they have distinct formulations.
“In addition to the regulatory snag of a CRL, IPX203 will need to compete with novel subcutaneous levodopa delivery systems. KOLs showed great enthusiasm for AbbVie’s ABBV-951 and NeuroDerm’s ND0612, which enable continuous infusion of carbidopa/levodopa and could create additional options to control severe motor fluctuations in advanced-stage patients.”