Promising Outcomes of Original Grant:
Accumulation and/or aggregation of alpha-synuclein is central to the pathogenesis of Parkinson’s disease (PD), and its reduction is expected to positively modify the course of the disease. PD01A is an alpha-synuclein-targeting vaccine. The Phase 1A trial demonstrated that PD01A is safe and well tolerated. Evaluation of participants' blood demonstrated induction of the intended alpha-synuclein-reactive antibodies. Further analyses indicated that antibody-responders benefited from the PD01A vaccination regardless of the course of their disease. Follow-up of participants in the study revealed that the vaccination-induced antibody response waned over time; therefore, an additional booster immunization will be administered. This study will determine if an additional boost is safe and, if so, whether it can enhance the antibody response.
Objectives for Supplemental Investigation:
To advance further development of PD01A, we must determine if it is possible to repeatedly boost the PD01A-induced immune response. To this end, individuals with PD who participated in the PD01A Parkinson program and have received a total of 5 PD01A immunizations will be offered another boost of PD01A.
Importance of This Research for the Development of a New PD Therapy:
Previous studies established the safety of PD01A immunizations and demonstrated the importance of the dose and vaccination schedule for its immunological efficacy. Together, these results supported further development of PD01A. We now take the next step in testing whether a second boost immunization can enhance the antibody response, which would indicate the possibility of maintaining the response over a prolonged period of time. This, in turn, is necessary for a vaccine to slow disease progression. These results will help advance PD01A into Phase II testing, the next development phase.