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 18 227

Opportunity Information: Apply for PAR 18 227

This National Institutes of Health (NIH) grant opportunity, PAR-18-227, supports R01 research projects focused on creating and applying new PET or SPECT radioligands that can image targets in the human brain. The central goal is to expand the toolkit of imaging biomarkers that can be used both to speed up central nervous system (CNS) drug discovery and to deepen understanding of the biology underlying CNS disorders. The FOA is specifically oriented toward ligand development efforts that do not stop at chemistry or in vitro validation, but also include some level of pilot testing or feasibility evaluation, which can occur in preclinical studies, through quantitative model development, and/or in clinical studies. Clinical trials are allowed but not required, which gives applicants flexibility to propose anything from advanced preclinical packages with first-in-human readiness to early clinical feasibility and quantification work.

From a scientific standpoint, the announcement emphasizes novel radioligand development for PET (positron emission tomography) and SPECT (single photon emission computed tomography) imaging in the human brain. In practice, this typically involves identifying a relevant molecular target (for example, receptors, transporters, enzymes, aggregated proteins, neuroinflammatory markers, or synaptic markers), designing and radiolabeling a compound that binds that target with high selectivity and suitable kinetics, and demonstrating that the signal can be quantified reliably in brain. Because the FOA explicitly calls out biomarker use for drug discovery, competitive projects commonly address how the ligand could be used for target engagement, receptor occupancy, dose selection, patient stratification, pharmacodynamic readouts, or monitoring disease-related changes over time. At the same time, the FOA also welcomes ligands primarily aimed at studying pathophysiology, meaning applications that help map where and how disease processes operate in vivo, potentially linking imaging outcomes to symptoms, progression, or other biological measures.

A key feature is the expectation that projects integrate feasibility evaluation rather than treating imaging as a purely methodological exercise. That can include preclinical imaging proof-of-concept, kinetic/compartmental modeling work to establish quantification methods, development of reference region strategies or metabolite correction approaches, reproducibility assessments, and early-stage human imaging to confirm brain penetration, specificity, and usable signal-to-noise. While the text provided does not list detailed review criteria, the intent implies that successful applications should present a clear translational plan showing how the ligand will progress from design and validation to an imaging tool that can realistically be deployed in humans and used as a biomarker in neuroscience research or therapeutic development.

The opportunity is offered as a discretionary grant under the NIH R01 mechanism, with the funding activity category listed under Education and Health. It is associated with multiple CFDA numbers (93.242, 93.273, 93.279, 93.286, 93.866), reflecting that several NIH institutes or programs may participate depending on the specific CNS focus and target area. The FOA was created on 2017-11-17, and the original closing date shown is 2020-01-07. No award ceiling or expected number of awards is provided in the source data excerpt, so applicants would typically look to standard NIH R01 budget policies and the specific institute guidance to gauge likely budget ranges and paylines.

Eligibility is broad and includes many types of domestic U.S. applicants such as state, county, city/township, and 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 not federally recognized; public housing authorities/Indian housing authorities; nonprofits with and without 501(c)(3) status (other than universities); for-profit organizations other than small businesses; and small businesses. The FOA also explicitly highlights additional eligible applicant categories, including Alaska Native and Native Hawaiian Serving Institutions, AANAPISI institutions, Hispanic-serving institutions, Historically Black Colleges and Universities (HBCUs), Tribally Controlled Colleges and Universities (TCCUs), eligible federal agencies, faith-based or community-based organizations, regional organizations, U.S. territories or possessions, and non-U.S. entities (foreign organizations). In short, the NIH is signaling that it wants a wide range of institutions to participate, including organizations that may bring specialized radiochemistry, imaging infrastructure, clinical populations, or unique collaborative networks to CNS imaging ligand development.

Overall, this FOA is best understood as a translational imaging methods and biomarker development program for the brain, aimed at delivering new PET/SPECT ligands that can be used in humans and that are positioned to answer high-value questions in CNS drug development and disease biology. It supports the full arc of work needed to turn a promising target-binding molecule into a practical, quantifiable imaging biomarker, with room for either preclinical-to-clinical bridging studies or early clinical feasibility, depending on where the proposed ligand sits on the development timeline.

• The National Institutes of Health in the education, 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, 93.273, 93.279, 93.286, 93.866.
• This funding opportunity was created on 2017-11-17.
• Applicants must submit their applications by 2020-01-07. (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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