Patients also tolerated the therapy well, researchers said.
Werner Poewe, a professor at Austria’s Medical University Insbruck, presented the results at the 21stInternational Congress of Parkinson’s Disease and Movement Disorders in Vancouver, Canada, June 4-8.
He is part of a European collaboration known as SYMPATH whose aim is to develop vaccines targeting the aSyn protein. The collaboration involves AFFiRiS and seven academic and industry partners in Germany, France and Austria. The European Union is financing SYMPATH.
The 52-week Phase 1 trial (NCT02267434) evaluated the immune response, safety and tolerability of AFFITOPE PD03A in patients with early Parkinson’s disease.
Researchers randomized 36 patients to receive one of two doses of the vaccine or a placebo. One dose was five times larger than the other. The basic immunization was an injection a month for four months. At 36 weeks, patients received a booster immunization.
The vaccine triggered immune responses against the aSyn protein over time. The reactions were dose-dependent, meaning that the higher dose triggered a stronger response than the lower one. The booster immunization reactivated the vaccine’s antibody production, researchers said.
Both doses of the vaccine were well tolerated, with patients reporting no serious adverse events.
AFFITOPE PD03A is a synthetically produced aSyn-mimicking peptide — or protein component — that targets the aSyn protein.
ASyn plays a key role in the onset and progression of Parkinson’s. Current treatments can only alleviate the disease’s symptoms. Scientists say aSyn has the potential to actually slow the disease’s progression.
SYMPATH researchers hope to develop an aSyn-targeting vaccine for multiple system atrophy as well as Parkinson’s. The consortium has already created a vaccine besides AFFITOPE PD03A, known as AFFITOPE PD01A. A key reason the EU became involved in the project is that current therapies for many neurodegenerative conditions are unable to alter the diseases’ course.
“The immunogenicity profile [of AFFITOPE PD03A] looks encouraging and supports the hypothesis that patients elicit an antibody response specific to alpha synuclein, a protein that is believed to be contributing to the pathogenesis of Parkinson’s,” Poewe, the principal investigator of the study, said in a press release.