Another major milestone in the journey of the Parkinson’s biomarker has been achieved. In late summer 2024, the U.S. Food and Drug Administration (FDA) issued a “Letter of Support” to encourage drug developers to use the alpha-synuclein seed amplification assay (αSyn-SAA) — a Parkinson’s biomarker discovered in 2023 — in research and clinical trials. Because the tool can objectively detect early biology related to Parkinson’s and related diseases, including Dementia with Lewy Bodies (DLB), even before any symptoms emerge, trials using αSyn-SAA are better positioned to test therapies that aim to delay or even prevent the onset of disease, which could speed drug trials and improve their chances of success.  

This important moment of recognition stems in part from multi-stakeholder collaboration by The Michael J. Fox Foundation for Parkinson’s Research (MJFF) and the Critical Path Institute (C-Path), with both organizations supporting use of the biomarker for clinical trials and advancing new drugs for PD.  

An FDA Letter of Support is an important proof point that a biomarker has enough evidence and potential to move the field forward. In the letter, FDA emphasizes that their support stems from significant evidence made possible through the Foundation’s landmark study, the Parkinson’s Progression Markers Initiative (PPMI). The Letter of Support states: “Key success factors for PPMI include the alignment, harmonization, and transparency of data collection methodologies and open sharing of data.” 

Heralded as “the study that’s changing everything” about how Parkinson’s is diagnosed, managed and treated, PPMI and its data are made possible by more than 3,000 in-clinic and 42,000 online research volunteers with and without Parkinson’s disease. 

“The search for a Parkinson’s biomarker has been a centerpiece of The Michael J. Fox Foundation’s mission-critical work since our earliest days,” said Todd Sherer, PhD, MJFF’s chief mission officer. “As we continue working urgently toward better treatments and a cure, the FDA’s backing of αSyn-SAA is an important milestone in advancing today’s robust pipeline of Parkinson’s therapies that patients and families urgently need.”  

Building on the Biomarker Breakthrough 

PPMI data first validated αSyn-SAA in April 2023 has set about a sea change in how we understand PD and its underlying biology.  

Clinical trials for potential new Parkinson’s therapies are historically time-consuming and costly — the development of a single new therapy takes decades and costs billions of dollars. As an objective and reliable biomarker of Parkinson’s biology — and now with the support of the FDA — αSyn-SAA holds potential to make these trials faster, clearer and more efficient. By doing so, it significantly decreases the risk for industry to invest in the development of potential blockbuster therapies, including preventive approaches. With αSyn-SAA in hand, it will be possible to establish objective endpoints for clinical trials of Parkinson’s treatments, ensure study participants exhibit relevant pathology, and detect therapy-induced changes in their status.   

The FDA also acknowledged the potential of the neuronal synuclein disease integrated staging system (NSD ISS), a proposed way of staging patients with Parkinson’s based in part on αSyn-SAA. NSD ISS creates a framework to identify and acknowledge those with Parkinson’s biology who may not have clinical symptoms yet. The concepts of the NSD-ISS framework have also emerged largely from the Foundation’s landmark PPMI study. Overall, the FDA’s recognition of NSD ISS in its letter of support for αSyn-SAA shows just how rapidly our characterization of PD is evolving. 

“In my conversations to my fellow patients, I have used the analogy of previous Parkinson's drug research as ‘cave exploration in the dark’,” said Kevin Kwok, PharmD, former biopharmaceutical executive, PPMI community advisory board member and patient advocate diagnosed with PD in 2009. “PPMI's biomarker initiative has resulted in the creation of an alpha-synuclein ‘lantern’ so we are no longer groping in the darkness but now have biological illumination of the cavern we are exploring.” 

The Michael J. Fox Foundation continues to fund advances in technology and medicine to drive toward effective therapies that can prevent, slow or stop disease progression.   

You can be a part of that mission.   

The Parkinson’s Progression Markers Initiative (PPMI) is our landmark study on a mission to stop the disease. It is open to anyone over age 18 in the United States. Whether you have Parkinson’s or not, join the study that's changing everything.  

Recently diagnosed with PD or live outside the U.S.? Connect with the PPMI team.