Two-year University of Arizona study will use human brain-cell models to investigate sex-specific biology and help guide future research and clinical trials.
Critical Path Institute (C-Path) and the University of Arizona are launching a two-year research project to investigate how Parkinson’s disease may work differently in women and men.
Led by Lalitha Madhavan, M.D., Ph.D., professor of neurology at the University of Arizona, the study will compare brain cells grown from women and men with Parkinson’s. Researchers hope to identify biological differences that may help explain differences in symptoms and how the disease progresses.
Why this research matters to women
Women with Parkinson’s have described differences in their experience of the disease, including how long it takes to receive a diagnosis and the balance of movement-related and non-movement symptoms they experience. Yet women have been underrepresented in Parkinson’s research, and scientists still have much to learn about the biological reasons for these differences.
Parkinson’s is more common in men. A 2015 analysis found that men had about 1.5 to 2 times the risk of developing the disease compared with women. But understanding risk is only part of the picture. Studying the biology of Parkinson’s in women may help researchers better understand how the disease develops and progresses—and support more informed decisions about how future clinical trials are designed and treatments are evaluated.
“Addressing sex-specific biology is an essential and long-overdue step in Parkinson’s research,” said Diane Stephenson, Ph.D., C-Path’s vice president of neurology and executive director of the Critical Path for Parkinson’s Consortium. “This foundational work can provide evidence to improve how clinical trials are designed and help ensure new therapies are evaluated with greater precision.”
Studying brain cells in the lab
University of Arizona researchers will use stem-cell lines from people with sporadic Parkinson’s disease. These cells, provided through the Parkinson’s Progression Markers Initiative (PPMI), can be developed into cortical neurons—brain cells that researchers can study in the laboratory.
The team will compare neurons from women and men with Parkinson’s with cells from people of similar age and sex who do not have the disease. Researchers will examine cell characteristics and function, including how the cells respond electrically and which proteins they produce.
The project is part of C-Path’s Global Evidence in Medicine for Parkinson’s Disease (GEM-PD) initiative, launched in March 2025 to address questions about how sex-specific biology may affect Parkinson’s symptoms, progression and treatment. It is also part of GEM-PD’s real-world evidence workstream.
“This new phase of our partnership further accelerates our commitment to understanding how Parkinson’s affects women,” said Kristen Swingle, M.S., C-Path’s president and chief operating officer. “The specialized neurons Dr. Madhavan’s lab will grow are essential to answering questions that clinical information alone cannot.”
Madhavan said the project will use the University of Arizona’s stem-cell expertise to create human-derived models that make it possible to investigate questions about Parkinson’s biology in women.
A human-cell-based research approach
The project uses a New Approach Methodology, or NAM: a research model based on human cells rather than traditional animal-based preclinical systems. C-Path also supports the development and use of NAMs through its New Approach Methodologies Developer Coalition.
The partnership runs from April 2026 through June 2028 and includes four milestones. The researchers expect to share their findings at scientific meetings, including the International Society for Stem Cell Research and the AD/PD meeting, and publish a research paper.
To learn more about GEM-PD, visit c-path.org/program/critical-path-for-parkinsons.
About Critical Path Institute
Founded in 2005 as a public-private partnership in response to the FDA’s Critical Path Initiative, Critical Path Institute works with collaborators to advance better treatments for people around the world. Its programs and consortia bring together more than 1,600 scientists and representatives from government and regulatory agencies, academia, patient organizations, disease foundations, pharmaceutical companies and biotechnology companies. C-Path is headquartered in Tucson, Arizona, with its European subsidiary based in Amsterdam, Netherlands. Learn more at c-path.org.
Funding disclosure: Critical Path Institute is supported by the Food and Drug Administration of the U.S. Department of Health and Human Services. According to the organization, 43% of its funding comes from FDA/HHS ($20,724,703) and 57% from non-government sources ($27,346,613). The contents are those of the authors and do not necessarily represent the official views of, or an endorsement by, FDA/HHS or the U.S. Government.
