Monoclonal Antibodies No Better Than Placebo for Early Parkinson Disease

HealthDay News — The monoclonal antibodies cinpanemab and prasinezumab show almost no benefit for early Parkinson disease, according to two phase 2 trials published in the August 4 issue of the New England Journal of Medicine.

Anthony E. Lang, MD, from the University of Toronto, and colleagues conducted a 52-week phase 2 trial involving participants with early Parkinson disease who were randomly assigned to receive infusions of placebo (control) or cinpanemab at a dose of 250mg, 1250mg, or 3500mg every 4 weeks (100, 55, 102, and 100 participants, respectively), followed by an active-treatment dose-blinded extension period for up to 112 weeks. Due to lack of efficacy, the trial was stopped after the week 72 interim analysis. The researchers found that the change to week 52 in the Movement Disorder Society-sponsored revision of the Unified Parkinson’s Disease Rating Scale (MDS-UPDRS) score was 10.8, 10.5, 11.3, and 10.9 points, respectively.

Gennaro Pagano, MD, PhD, from the Roche Innovation Center Basel in Switzerland, and colleagues randomly assigned participants with early-stage Parkinson disease to receive intravenous placebo or prasinezumab 1500mg or 4500mg every 4 weeks for 52 weeks in a phase 2 trial (105, 105, and 106 participants, respectively). The researchers found that the changes from baseline to 52 weeks in the MDS-UPDRS scores were 9.4 in the placebo group, 7.4 in the 1500-mg group, and 8.8 in the 4500-mg group.

“Neither trial showed benefit with respect to the primary or secondary end points save that there was a suggestion that treatment with low-dose prasinezumab slowed progression on a secondary end point,” write the authors of an accompanying editorial.

The Lang study was funded by Biogen, the manufacturer of cinpanemab; the Pagano study was funded by F. Hoffmann-La Roche and Prothena Biosciences, the manufacturers of prasinezumab.

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