Development and Application of PET and SPECT Imaging Ligands as Biomarkers for Drug Discovery and for Pathophysiological Studies of CNS Disorders (R01 Clinical Trial Optional) | PAR 25 036

Opportunity Information: Apply for PAR 25 036

The National Institutes of Health (NIH) is offering an R01 research grant opportunity (PAR-25-036) focused on advancing brain imaging tools for central nervous system (CNS) research and drug development. The opportunity supports projects that develop and evaluate new radioligands for positron emission tomography (PET) or single photon emission computed tomography (SPECT) imaging in the human brain. The main goal is to generate the kind of rigorous, decision-ready evidence needed to move promising imaging ligands forward into clinical research, where they can serve as biomarkers for understanding disease biology and for guiding therapeutic discovery.

The scientific emphasis is on creating and testing novel PET or SPECT ligands that can measure relevant molecular targets in the living human brain. Applications are expected to include strong development and evaluation plans, and the NOFO also encourages incorporating pilot or clinical feasibility work that leverages previously collected preclinical data. In practical terms, this means applicants can build on existing preclinical findings (for example, binding specificity, selectivity, stability, or animal imaging results) and then perform the additional steps needed to demonstrate whether a ligand is suitable for human brain imaging, including early feasibility assessments that help determine whether it is ready for broader clinical research use.

The imaging ligands supported under this program are intended to function as biomarkers in two closely related contexts. First, they can help drug discovery by enabling target engagement studies, dose selection, pharmacodynamic readouts, and early go/no-go decisions for candidate therapeutics. Second, they can be used to study pathophysiological mechanisms in CNS disorders, helping researchers map receptor systems, enzymes, transporters, aggregated proteins, neuroinflammation markers, or other molecular processes in vivo. The overall expectation is that funded work will produce the critical validation-style data needed to justify and enable clinical research applications of these ligands, rather than stopping at early chemistry or purely exploratory work.

This is a discretionary grant mechanism under the NIH R01 activity, with clinical trials listed as optional, meaning applicants may propose studies that do or do not meet the NIH definition of a clinical trial, depending on the project design. The funding announcement is categorized under health-related research activities, with CFDA numbers 93.242 and 93.866. While the listing does not provide an award ceiling or expected number of awards, it does provide a firm application due date of May 7, 2026. The opportunity was created on November 6, 2024.

Eligibility is broad and includes many organization types across academia, government, nonprofit, and industry. Eligible applicants include state, county, and local governments; special district governments; independent school districts; public and state-controlled institutions of higher education; private institutions of higher education; federally recognized Native American tribal governments; tribal organizations that are not federally recognized; public housing authorities and Indian housing authorities; nonprofits with or without 501(c)(3) status (excluding institutions of higher education in those nonprofit categories); for-profit organizations (other than small businesses); and small businesses. The NOFO also explicitly highlights additional eligible applicant categories such as Alaska Native and Native Hawaiian Serving Institutions, Asian American Native American Pacific Islander Serving Institutions (AANAPISIs), Hispanic-serving Institutions, Historically Black Colleges and Universities (HBCUs), Tribally Controlled Colleges and Universities (TCCUs), faith-based or community-based organizations, eligible federal agencies, regional organizations, U.S. territories or possessions, and non-U.S. entities (foreign organizations).

In short, this NIH funding opportunity is designed for teams capable of bridging radiochemistry, imaging physics, pharmacology, and translational/clinical neuroscience to deliver new PET or SPECT brain imaging ligands that are ready to be used as credible biomarkers. Successful projects will typically be those that can demonstrate a clear path from ligand concept and preclinical support to human-relevant evaluation, producing the evidence needed to justify broader clinical research and to strengthen both drug development pipelines and mechanistic studies of CNS disorders.

• The National Institutes of Health in the health sector is offering a public funding opportunity titled "Development and Application of PET and SPECT Imaging Ligands as Biomarkers for Drug Discovery and for Pathophysiological Studies of CNS Disorders (R01 Clinical Trial Optional)" and is now available to receive applicants.
• Interested and eligible applicants and submit their applications by referencing the CFDA number(s): 93.242, 93.866.
• This funding opportunity was created on 2024-11-06.
• Applicants must submit their applications by 2026-05-07. (Agency may still review applications by suitable applicants for the remaining/unused allocated funding in 2026.)
• Eligible applicants include: State governments, County governments, City or township governments, Special district governments, Independent school districts, Public and State controlled institutions of higher education, Native American tribal governments (Federally recognized), Public housing authorities/Indian housing authorities, Native American tribal organizations (other than Federally recognized tribal governments), Nonprofits having a 501 (c) (3) status with the IRS, other than institutions of higher education, Nonprofits that do not have a 501 (c) (3) status with the IRS, other than institutions of higher education, Private institutions of higher education, For-profit organizations other than small businesses, Small businesses, Others.

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