ADVERTISEMENT
Two Monoclonal Antibody Treatments Fail to Affect Early Parkinson’s Progression
A pair of phase 2 trials investigating two different monoclonal antibodies for early Parkinson disease found neither offered meaningful benefit in slowing disease progression compared with placebo. Results from both studies were published in The New England Journal of Medicine.
In one multicenter, double-blind trial, investigators evaluated cinpanemab, which binds to α-synuclein, in 357 patients with early Parkinson disease. Every 4 weeks for 52 weeks, participants received intravenous infusions of placebo (100 patients), 250 mg cinpanemab (55 patients), 1250 mg cinpanemab (102 patients), or 3500 mg cinpanemab (100 patients). An active-treatment dose-blinded extension took place afterward, which was planned for up to 112 weeks. Researchers, however, stopped the study after an interim analysis at week 72 demonstrated a lack of efficacy.
According to the study, adjusted mean differences from baseline on the Movement Disorder Society-sponsored revision of the Unified Parkinson’s Disease Rating Scale (MDS-UPDRS) total score at 52 weeks were -0.3 points with 250 mg cinpanemab, 0.5 points with 1250 mg cinpanemab, and 0.1 point with 3500 mg cinpanemab compared with placebo. At 72 weeks, adjusted mean differences between participants who received cinpanemab through 72 weeks and the pooled group that 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. Additionally, dopamine transporter single-photon-emission computed tomography showed no differences between cinpanemab and placebo at week 52.
In another trial, researchers investigated prasinezumab, also directed at aggregated α-synuclein, in 316 patients with early Parkinson’s disease. Every 4 weeks for 52 weeks, participants received intravenous placebo (105 patients) 1500 mg prasinezumab (105 patients), or 4500 mg prasinezumab (106 patients).
At 52 weeks, mean changes from baseline were in -2.0 with 1500-mg prasinezumab and -0.6 with 4500-mg prasinezumab compared with placebo, researchers reported. Furthermore, single-photon-emission computed tomography revealed no substantial difference between prasinezumab treatment and the placebo in dopamine transporter levels.
“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,” researchers wrote, adding that, “infusion reactions occurred in 19.0% and 34.0%, respectively.”
References
