ABBV 951 showed improvement in controlling motor fluctuations compared to oral levodopa/carbidopa medication.

The study met its primary endpoint of increase from baseline in "On" time (hours) without troublesome dyskinesia (involuntary movements) after 12 weeks based on the Parkinson's Disease Diary (PD Diary). These results will be a key component of global regulatory submissions. The increase in "On" time at week 12 was 2.72 hours for ABBV-951 versus 0.97 hours for oral levodopa/carbidopa (LD/CD) (p= 0.0083). Improvements in "On" time were observed as early as the first week and persisted throughout the 12 weeks. It was also observed that an improvement from baseline in hours of average daily normalized "Off" time followed a similar pattern in reductions versus oral LD/CD after the first week and persisting through week 12. Decreases in "Off" time after 12 weeks were 2.75 hours for ABBV-951 versus 0.96 hours for oral LD/CD (p=0.0054).

The majority of the adverse events (AEs) reported were non-serious and mild to moderate in severity in the ABBV 951 group. Incidence of serious AEs were 8% and 6% in the ABBV 951 group and oral LD/CD group, respectively. There was one patient with a treatment-emergent AE leading to death in the oral LD/CD group and none in the ABBV 951 group. The most common AEs reported in greater than 5% in the ABBV 951 group were infusion site AEs (erythema, pain, cellulitis, edema, bruising, hemorrhage, nodule, induration, infection, and pruritus), dyskinesia, "On" and "Off" phenomenon, fall, hallucinations (including visual hallucination), balance disorder, constipation and peripheral swelling. The incidence of infusion site AEs was higher in the ABBV 951 group than in the oral LD/CD group and most of them were non-serious, mild to moderate in severity, resolved with or without treatment and none led to systemic complications. Incidence of hallucination and psychosis AEs was higher in the ABBV 951 group than in the oral LD/CD group. Most of these AEs were non-serious, mild to moderate in severity. Incidence of falls and associated injuries was lower in the ABBV 951 group compared to the oral LD/CD group. Adverse events led to study treatment discontinuation in 21.6% of patients in the ABBV 951 group and 1.5% in the oral LD/CD group.

Full results from the Phase III study will be presented at a future medical meeting or submitted for publication in a peer-reviewed journal. ABBV 951 is an investigational therapy and it is not approved for use. The safety and efficacy of ABBV 951 have not been evaluated by regulatory authorities.