To present the adverse event (AE) profile of IPX203 in the Phase 3 clinical trials in Parkinson disease (PD).

IPX203 is an investigational oral extended-release carbidopa-levodopa (CD-LD) designed to produce prolonged therapeutic LD plasma concentrations. IPX203 has shown improvement in “Good On” time compared to immediate-release CD-LD.

Safety data from a multi-center, double-blind, randomized, active-controlled Phase 3 study and an open-label extension Phase 3 study were combined and analyzed.

Safety population consisted of 630 patients with PD experiencing motor fluctuations, with a mean age of 66.5yrs (9.0), and mean duration of disease of 8.5yrs (4.9). The average total daily dose (TDD) of IPX203 was 1520.97 mg (±587.78); most subjects (83.0%) received IPX203 at an average TDD between 800 mg and <2400 mg of LD. The average daily dosing frequency of IPX203 was 3.08 times/day, the mean (range) treatment duration was 242.9 (2 to 553) days and person-years of exposure was 388.34. The majority, 385/584 (65.9%), were exposed to IPX203 for 6 months or longer, and 179 (30.7%) were exposed for 12 months or longer.

In the Phase 3 studies pool, 397 (67.4%) of IPX203 subjects experienced 1355 treatment-emergent AEs (TEAEs) (837 mild, 419 moderate, 99 severe). Of these, 205 (34.8%) experienced 471 TEAEs that were treatment-related. The most reported TEAEs were dyskinesia (10.7%), nausea (7.5%), fall (5.9%), and urinary tract infection (5.3%). The analysis of TEAEs by duration of exposure to study treatment showed that most IPX203 subjects (55.0%) experienced TEAEs (first onset) within the first 3 months. The occurrence of TEAEs remained stable over time.

Considering the disease duration and presence of motor fluctuations in the PD cohort enrolled in our Phase 3 trials, IPX203 was generally safe and well tolerated; the safety profile was stable over time and consistent with the known effects of other LD formulations.