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Trial of Prasinezumab in Early-Stage Parkinson’s Disease

List of authors.
  • Gennaro Pagano, M.D., Ph.D.,
  • Kirsten I. Taylor, Ph.D.,
  • Judith Anzures-Cabrera, Ph.D.,
  • Maddalena Marchesi, M.D.,
  • Tanya Simuni, M.D.,
  • Kenneth Marek, M.D., Ph.D.,
  • Ronald B. Postuma, M.D.,
  • Nicola Pavese, M.D., Ph.D.,
  • Fabrizio Stocchi, M.D., Ph.D.,
  • Jean-Philippe Azulay, Ph.D.,
  • Brit Mollenhauer, M.D.,
  • Lydia López-Manzanares, M.D.,
  • David S. Russell, M.D., Ph.D.,
  • James T. Boyd, M.D.,
  • Anthony P. Nicholas, M.D., Ph.D.,
  • María R. Luquin, Ph.D.,
  • Robert A. Hauser, M.D.,
  • Thomas Gasser, M.D.,
  • Werner Poewe, M.D., Ph.D.,
  • Benedicte Ricci, Ph.D.,
  • Anne Boulay, Ph.D.,
  • Annamarie Vogt, Ph.D.,
  • Frank G. Boess, Ph.D.,
  • Juergen Dukart, Ph.D.,
  • Giulia D’Urso, Ph.D.,
  • Rebecca Finch, M.Sc.,
  • Stefano Zanigni, M.D., Ph.D.,
  • Annabelle Monnet, M.Sc.,
  • Nathalie Pross, Ph.D.,
  • Andrea Hahn, M.Sc.,
  • Hanno Svoboda, Ph.D.,
  • Markus Britschgi, Ph.D.,
  • Florian Lipsmeier, Ph.D.,
  • Ekaterina Volkova-Volkmar, Ph.D.,
  • Michael Lindemann, Ph.D.,
  • Sebastian Dziadek, Ph.D.,
  • Štefan Holiga, Ph.D.,
  • Daria Rukina, Ph.D.,
  • Thomas Kustermann, Ph.D.,
  • Geoffrey A. Kerchner, M.D., Ph.D.,
  • Paulo Fontoura, M.D., Ph.D.,
  • Daniel Umbricht, M.D., Ph.D.,
  • Rachelle Doody, M.D., Ph.D.,
  • Tania Nikolcheva, M.D., Ph.D.,
  • and Azad Bonni, M.D., Ph.D.
  • for the PASADENA Investigators and Prasinezumab Study Group*



Aggregated α-synuclein plays an important role in the pathogenesis of Parkinson’s disease. The monoclonal antibody prasinezumab, directed at aggregated α-synuclein, is being studied for its effect on Parkinson’s disease.


Download a PDF of the Research Summary.

In this phase 2 trial, we randomly assigned participants with early-stage Parkinson’s disease in a 1:1:1 ratio to receive intravenous placebo or prasinezumab at a dose of 1500 mg or 4500 mg every 4 weeks for 52 weeks. The primary end point was the change from baseline to week 52 in the sum of scores on parts I, II, and III of the Movement Disorder Society–sponsored revision of the Unified Parkinson’s Disease Rating Scale (MDS-UPDRS; range, 0 to 236, with higher scores indicating greater impairment). Secondary end points included the dopamine transporter levels in the putamen of the hemisphere ipsilateral to the clinically more affected side of the body, as measured by 123I-ioflupane single-photon-emission computed tomography (SPECT).


A total of 316 participants were enrolled; 105 were assigned to receive placebo, 105 to receive 1500 mg of prasinezumab, and 106 to receive 4500 mg of prasinezumab. The baseline mean MDS-UPDRS scores were 32.0 in the placebo group, 31.5 in the 1500-mg group, and 30.8 in the 4500-mg group, and mean (±SE) changes from baseline to 52 weeks were 9.4±1.2 in the placebo group, 7.4±1.2 in the 1500-mg group (difference vs. placebo, –2.0; 80% confidence interval [CI], –4.2 to 0.2; P=0.24), and 8.8±1.2 in the 4500-mg group (difference vs. placebo, –0.6; 80% CI, –2.8 to 1.6; P=0.72). There was no substantial difference between the active-treatment groups and the placebo group in dopamine transporter levels on SPECT. The results for most clinical secondary end points were similar in the active-treatment groups and the placebo group. Serious adverse events occurred in 6.7% of the participants in the 1500-mg group and in 7.5% of those in the 4500-mg group; infusion reactions occurred in 19.0% and 34.0%, respectively.


Prasinezumab therapy had no meaningful effect on global or imaging measures of Parkinson’s disease progression as compared with placebo and was associated with infusion reactions. (Funded by F. Hoffmann–La Roche and Prothena Biosciences; PASADENA number, NCT03100149.)

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Prasinezumab in Early Parkinson’s Disease

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Funding and Disclosures

Supported by F. Hoffmann–La Roche and Prothena Biosciences.

Disclosure forms provided by the authors are available with the full text of this article at

A data sharing statement provided by the authors is available with the full text of this article at

We thank all the participants and their families who participated in the trial, and the staff of the clinical trial sites around the world for their ongoing partnership and assistance. We also thank Lisa Michelle Restelli (Roche) and Amanda Gallagher (Chrysalis Medical Communications) for providing medical writing assistance and Megan Speakman (MediTech Media) for providing medical editing assistance with an earlier version of the manuscript; they were funded by F. Hoffmann–La Roche, in accordance with Good Publication Practice (GPP3) guidelines (

Author Affiliations

From the Neuroscience and Rare Diseases, Discovery and Translational Area (G.P., K.I.T., A. Boulay, A.V., F.G.B., J.D., G.D., H.S., M.B., S.D., Š.H., T.K., G.A.K., D.U., A. Bonni), and Pharmaceutical Sciences (B.R.), Roche Pharma Research and Early Development (pRED), and Roche pRED Informatics (F.L., E.V.-V., M.L.), Roche Innovation Center Basel, and Product Development Neuroscience (S.Z., A.M., N. Pross, P.F., R.D., T.N.) and Product Development Safety (M.M., D.R.), F. Hoffmann–La Roche — all in Basel, Switzerland; University of Exeter Medical School, London (G.P.), Roche Products, Welwyn Garden City (J.A.-C., R.F.), and the Clinical Ageing Research Unit, Newcastle University, Newcastle upon Tyne (N. Pavese) — all in the United Kingdom; the Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago (T.S.); Institute for Neurodegenerative Disorders, New Haven, CT (K.M., D.S.R.); the Department of Neurology, McGill University, and Montreal Neurological Institute, Montreal (R.B.P.); University San Raffaele Roma and the Institute for Research and Medical Care, IRCCS San Raffaele Pisana, Rome (F.S.); Centre Hospitalier de la Timone, Marseille, France (J.-P.A.); Paracelsus-Elena-Klinik, Kassel (B.M.), the Department of Neurology, University Medical Center Göttingen, Göttingen (B.M.), Hertie Institute for Clinical Brain Research, University of Tübingen, and the German Center for Neurodegenerative Diseases, Tübingen (T.G.), the Institute of Neurosciences and Medicine, Brain and Behavior, Research Center Jülich, Jülich (J.D.), the Institute of Systems Neuroscience, Medical Faculty, Heinrich Heine University Düsseldorf, Düsseldorf (J.D.), and Excelya Germany, Freiburg (A.H.) — all in Germany; the Department of Neurology, University Hospital de La Princesa, Madrid (L.L.-M.), and University Clinic of Navarra, Pamplona (M.R.L.) — both in Spain; University of South Florida, Tampa (R.A.H.); University of Vermont Larner College of Medicine, Burlington (J.T.B.); University of Alabama Medical Center, Birmingham (A.P.N.); and the Department of Neurology, Innsbruck Medical University, Innsbruck, Austria (W.P.).

Dr. Pagano can be contacted at or at the Neuroscience and Rare Diseases, Discovery and Translational Area, Roche Pharma Research and Early Development, Roche Innovation Center Basel, Grenzacherstr. 124, Basel 4070, Switzerland.

The members of the PASADENA Investigators and Prasinezumab Study Group are listed in the Supplementary Appendix, available at