Evaluate outcomes (up to 3 years) from the ongoing Extension Period of the InfusON study (NCT02339064) of continuous subcutaneous apomorphine infusion (CSAI).

Primary data from InfusON showed that CSAI as adjunctive treatment for Parkinson disease (PD) motor fluctuations was generally safe and provided ongoing reduction in OFF time and corresponding improvement in Good ON time (ON time without troublesome dyskinesia) over a 52-Week Maintenance Period.

This open-label U.S. study enrolled individuals experiencing ≥3 hours (h) daily OFF time despite optimized levodopa plus current or prior use of ≥1 additional therapy. CSAI was initiated with a 1-2 mg bolus then 1 mg/h infusion, titrated to optimal efficacy and tolerability (not exceeding 8 mg/h or 150 mg/day), followed by a 52-week Maintenance Period. Individuals completing Maintenance could continue in an Extension Period.

Of 99 participants, 69 completed Maintenance Week 12 (primary efficacy timepoint), and 48 completed Maintenance Week 52. Of 45 participants entering Extension, 27 completed ≥2 years, and 21 completed ≥3 years. By Week 12, mean (SD) daily OFF time decreased by -3.0 (3.2) h from a baseline of 6.6 (2.4) h (primary efficacy endpoint), and this was sustained at the 1‑year: -3.2 (3.2) h, 2-year: -2.9 (3.2) h and 3-year: -3.8 (4.3) h visits. Corresponding Week 12 increases in Good ON time were 3.1 (3.4) h from a baseline of 9.3 (2.6) h, also sustained at the 1-year: 3.7 (3.3) h, 2-year: 3.2 (3.4) h and 3-year: 3.7 (3.6) h visits. The fraction of participants who rated themselves as improved compared to baseline (Patient Global Impression of Change) was 90% at 1 year, 90% at 2 years, and 86% at 3 years. The most common adverse events were mostly mild infusion site nodules.

These data support the long-term safety, tolerability, and efficacy of adjunctive CSAI.