Subcutaneous Apomorphine Infusion Titration Reaches Optimization Without Antiemetics in Real-World PD Cohort

Early real-world data presented at the 2026 Advanced Therapeutics in Movement & Related Disorders (ATMRD) Congress suggest that continuous subcutaneous apomorphine infusion (CSAI; Onapgo; Supernus Pharmaceuticals) can be titrated to a first optimization dose in most patients with Parkinson's disease (PD) without antiemetic pretreatment.¹

The findings come from the Clinical Nurse Navigator (CNN) program database, which captures titration and dosing data from patients who opted into Supernus's nurse-support program during the first 6 months of U.S. market availability following Onapgo's FDA approval in April 2025.

Background and Program Design

CSAI has been used globally since the 1980s to manage motor fluctuations in PD and received FDA approval in the United States in April 2025 as Onapgo. Because CSAI represents a new therapy type in the U.S. market, Supernus Pharmaceuticals developed the CNN program to provide education and support to patients, clinicians, and care partners. The program is staffed by licensed nurses experienced with PD and Onapgo, and includes home visits starting pre-treatment and continuing through maintenance therapy.

Led by senior author Mindy Grall, PhD, MSN, a senior director of Medical Affairs at Supernus, the analysis objective was to characterize CSAI titration patterns among patients who opted into the CNN program, using data recorded in the CNN database from initiation through first optimization dose, defined by patient and healthcare provider as the dose providing the best initial balance of efficacy and tolerability.

Titration Findings

As of November 3, 2025, 558 patients had started CSAI through the CNN program. The most common starting dose was 1.0 mg/h, used in 98.7% of patients, with 91.8% of initiations conducted at the patient's home. The first titration visit occurred approximately 1 day after the initiation visit for 89.9% of patients; subsequent titration visits were spaced approximately 1 week apart. Most common doses at titration visits 1, 2, and 3 were 1.5 mg/h, 2.0 mg/h, and 2.5 mg/h, respectively.

Of the 558 starts, 536 (96.1%) reached titration visit 1, 495 (88.7%) reached titration visit 2, and 436 (78.1%) reached titration visit 3 by January 21, 2026. A total of 252 patients (45.2%) had reached a first optimization dose by that date, with a median of 6 titration visits required (range, 1 to 14) and a mean of 63 days from start to first optimization. The first optimization dose ranged from 1.0 to 6.0 mg/h, with a mean of 3.0 mg/h.

Notably, 99.2% of patients who reached a first optimization dose did so without antiemetic pretreatment; 99.3% of all starts did not use an antiemetic at initiation. This is a clinically meaningful finding, as nausea and vomiting have historically been significant tolerability barriers to apomorphine use and have driven antiemetic pretreatment protocols in markets with longer experience with the drug.^2,3

Safety and Discontinuation

As of January 21, 2026, 327 of 558 patients (58.6%) were still receiving CSAI and 231 (41.4%) had discontinued. Reasons for discontinuation included change in patient health status (15.2%), patient choice (11.8%), alternate therapy (7.3%), alternate therapy with Vyalev (2.0%), and other reasons (4.8%). Timing of discontinuation relative to optimization was not available at the time of analysis.

Limitations and Disclosures

The analysis was descriptive and limited by its observational design, lack of a comparator group, and the fact that nearly 55% of patients had not yet reached a first optimization dose at the time of the data cut. Discontinuation timing relative to optimization was not captured, limiting interpretation of tolerability outcomes. All three authors (Cindy Happel, Andrea Formella, and Mindy Grall) are employees of Supernus Pharmaceuticals, which sponsored the study and was fully involved in data analysis and interpretation.

Click here for more ATMRD 2026 coverage.

REFERENCES
1. Happel C, Formella A, Grall M. Initiation and titration of continuous subcutaneous apomorphine infusion (CSAI) in the United States: Early data from the Clinical Nurse Navigator (CNN) Program. Poster presented at: Advanced Therapeutics in Movement & Related Disorders (ATMRD) Congress; June 4-8, 2026; Washington, DC.
2. Stibe C, Lees A, Stern G. Subcutaneous infusion of apomorphine and domperidone in the treatment of parkinsonian on-off fluctuations. Lancet. 1987;1:71. https://doi.org/10.1016/S0140-6736(87)91924-3
3. Stibe CM, Lees AJ, Kempster PA, Stern GM. Subcutaneous apomorphine in parkinsonian on-off oscillations. Lancet. 1988;1(8582):403-406. doi:10.1016/S0140-6736(88)91193-2. https://doi.org/10.1016/S0140-6736(88)91193-2
4. Onapgo (apomorphine HCl injection, for subcutaneous use 4.8 mg/mL) prescribing information. Rockville, MD: NDD US Operations, LLC, a subsidiary of Supernus Pharmaceuticals, Inc.; 2025.
5. Trenkwalder C, Chaudhuri KR, Garcia Ruiz PJ, et al. Expert Consensus Group report on the use of apomorphine in the treatment of Parkinson's disease. Parkinsonism Relat Disord. 2015;21(9):1023-1030. doi:10.1016/j.parkreldis.2015.06.012. https://doi.org/10.1016/j.parkreldis.2015.06.012