In a French multicenter retrospective cohort of 50 mostly MSA-P patients with partial dopaminergic responsiveness, continuous subcutaneous apomorphine infusion yielded short‑term (6-month) improvement in motor fluctuations with generally acceptable tolerability.

The study supports symptomatic repurposing of apomorphine for selected MSA patients—useful for clinical management and designing symptomatic treatment trials—but provides limited mechanistic or disease‑modifying insight relevant to Parkinson's therapeutic discovery.

BACKGROUND: Continuous subcutaneous apomorphine infusion (CSAI) is effective in Parkinson's disease but has not been evaluated in multiple system atrophy (MSA). OBJECTIVE: To assess the 6-month efficacy and tolerability of CSAI in MSA patients. METHODS: French multicenter retrospective registry-based analysis of CSAI use in MSA. The primary outcome was the 6-month clinical response using the Clinical Global Impression Improvement (CGI-I) scale. Secondary outcomes included tolerability, indications, infusion parameters, and treatment course. RESULTS: Fifty patients were included; 94% had MSA-P. All had motor fluctuations and 88% showed a clinically meaningful dopaminergic response. CSAI was initiated for motor symptoms (100%) or pain (54%). At 6 months, most patients improved (36% "much," 54% "minimally"), mainly due to reduced motor fluctuations. Only 8% discontinued CSAI. Tolerability was rated good/excellent in 74%; 20% reported somnolence and/or orthostatic hypotension. CONCLUSION: In selected MSA patients with partial dopaminergic responsiveness and motor fluctuations, CSAI provided short-term clinical benefit with acceptable tolerability.