Monoclonal antibody no better than placebo for early Parkinson's disease: NEJM
USA: Cinpanemab, a monoclonal antibody, is no better than placebo as a disease-modifying treatment for Parkinson's disease, according to a recent study published in the New England of Medicine.
The study stated that "the effects of cinpanemab on clinical measures of disease progression and changes in dopamine transporter single-photon-emission computed tomography (DaT-SPECT) imaging did not differ from those of placebo over a 52-week period in patients with early Parkinson's disease."
Aggregated α-synuclein plays an important part in the pathogenesis of Parkinson's disease. Cinpanemab is a human-derived monoclonal antibody that binds to α-synuclein. It is being evaluated as a disease-modifying treatment for Parkinson's disease.
For this purpose, Anthony E. Lang and colleagues conducted a 52-week, multicenter, double-blind, phase 2 trial that included 357 participants with early Parkinson's disease. They were randomly assigned in the ratio of 2:1:2:2 to receive intravenous infusions of placebo (control; n=100) or cinpanemab at a dose of 250 mg (n=55), 1250 mg (n=102), or 3500 (n=100) mg every 4 weeks. This was followed by an active-treatment dose-blinded extension period for up to 112 weeks.
Changes from baseline in the Movement Disorder Society-sponsored revision of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS) total score (range, 0 to 236, with higher scores indicating worse performance) at weeks 52 and 72 were the primary endpoints. Secondary endpoints were MDS-UPDRS subscale scores and striatal binding as assessed on DaT-SPECT.
Key findings of the study include:
- The trial was stopped after the week 72 interim analysis owing to lack of efficacy.
- The change to week 52 in the MDS-UPDRS score was 10.8 points in the control group, 10.5 points in the 250-mg group, 11.3 points in the 1250-mg group, and 10.9 points in the 3500-mg group (adjusted mean difference vs. control, −0.3 points; and 0.1 points respectively.
- The adjusted mean difference at 72 weeks between participants who received cinpanemab through 72 weeks and the pooled group of those who started cinpanemab at 52 weeks was −0.9 points for the 250-mg dose, 0.6 points for the 1250-mg dose, and −0.8 points for the 3500-mg dose.
- Results for secondary endpoints were similar to those for the primary endpoints.
- DaT-SPECT imaging at week 52 showed no differences between the control group and any cinpanemab group.
- The most common adverse events with cinpanemab were headaches, nasopharyngitis, and falls.
"The effects of cinpanemab on clinical measures of disease progression and changes in DaT-SPECT imaging did not differ from those of placebo in In participants with early Parkinson's disease, over a 52-week period," the researchers conclude.
Reference:
The study titled, "Trial of Cinpanemab in Early Parkinson's Disease," was published in the New England Journal of Medicine.
DOI: 10.1056/NEJMoa2203395
