How to dose extended-release carbidopa-levodopa capsules (IPX203, CREXONT®) in patients with Parkinson's disease.

IPX203 (CREXONT®) is a novel, oral, extended-release (ER) carbidopa-levodopa (CD-LD) formulation, designed to rapidly achieve LD plasma concentrations similar to immediate-release (IR) CD-LD and to maintain LD concentrations for a longer duration than other oral CD-LD products. In the pivotal phase 3 clinical trial, IPX203 provided superior clinical benefit with fewer doses than IR CD-LD. Since the plasma concentration profile of IPX203 is different from that of IR LD, converting patients treated with IR LD to IPX203 requires a conversion strategy. In the pivotal phase 3 trial, patients on IR CD-LD were converted to IPX203 based on the most frequent single dose of the patient's stable dosing regimen of IR CD-LD. IPX203 was initially administered 3 times per day for most patients. Further titration was then undertaken based on clinical response, and patients were dosed 2 to 4 times per day. Of 589 patients previously treated with IR CD-LD, 506 patients completed the conversion to IPX203; the mg conversion ratio for individual doses was 2.8 at the beginning of the dose-conversion period and 2.9 after titration to clinical response, with the majority of IPX203 patients (84%) dosed 3 times per day. Objective: To provide guidance on dosing of IPX203 (CREXONT®) in clinical practice.