Ono Pharma reported Phase 2 ONO-2808 data in multiple system atrophy (MSA) at WPC 2026, showing a favorable safety profile and exploratory signals of disease-modifying potential, supporting advancement to Phase 3.
Written by: Chikkula Pavankumar PharmD
Reviewed By: Pharmacally Editorial Team
Ono Pharmaceutical Co., Ltd. announced new clinical findings from the randomized, double-blind, placebo-controlled Phase 2 ONO-2808-03 study (NCT05923866, jRCT2041230153) of ONO-2808 in multiple system atrophy (MSA). Results were shared in a poster presentation at the 7th World Parkinson Congress (WPC), held May 24–27, 2026, in Phoenix, Arizona, USA.
Study Design and Endpoints
The 24-week core study evaluated safety, tolerability, pharmacokinetics, and exploratory efficacy in early-stage MSA patients. The primary endpoint was the incidence of treatment-emergent adverse events (TEAEs). Exploratory endpoints included changes in modified Unified Multiple System Atrophy Rating Scale (mUMSARS) scores and MRI-based volumetric brain assessments.
Safety Outcomes
TEAEs occurred in 91% of placebo-treated participants (21/23) and 93% of ONO-2808-treated participants (64/69). No unexpected safety signals were observed, supporting continued clinical development.
Exploratory Efficacy Findings
Encouraging trends suggested potential suppression of disease progression. In parkinsonism-predominant MSA (MSA-P), mean mUMSARS score change at Week 24 was 3.90 (95% CI: 1.76–6.04) in placebo, compared with 1.39 (95% CI: -0.85–3.64) in the medium-dose group and 1.16 (95% CI: -1.10–3.41) in the high-dose group.
MRI analyses indicated dose-dependent attenuation of brain atrophy progression. While not powered for formal efficacy conclusions, the findings suggest disease-modifying potential.
Next Steps in Development
Based on Phase 2 results, Ono Pharma and affiliate Deciphera plan to initiate a pivotal Phase 3 study to further evaluate ONO-2808 in MSA.
Trial Overview
ONO-2808-03 is a multicenter Phase 2 trial conducted in Japan and the United States in patients within five years of MSA symptom onset. Ninety-two participants were randomized to receive one of three ONO-2808 dose levels or placebo once daily for 24 weeks, followed by an extension phase of up to 80 weeks assessing long-term safety and efficacy.
Mechanism of Action
ONO-2808 is an orally bioavailable selective S1P5 receptor agonist discovered by Ono Pharma. S1P5 receptors regulate oligodendrocyte differentiation and myelin stabilization. ONO-2808 is being investigated for its potential to promote remyelination and suppress α-synuclein accumulation, mechanisms that may help slow disease progression in MSA.
Disease Context
MSA is a rare, rapidly progressive neurodegenerative disorder characterized by parkinsonian features, cerebellar ataxia, autonomic dysfunction, and abnormal α-synuclein accumulation. Average life expectancy is approximately 9–10 years, with no disease-modifying therapies currently available.
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About the Writer
Chikkula Pavan Kumar (LinkedIn), PharmD is a Doctor of Pharmacy with a keen interest in clinical pharmacy, pharmacovigilance, and evidence-based practice. In his words, he is passionate about patient safety and translating complex medical information into clear, research-driven communication.