Fc-Dependent Mechanisms of Antibody-Mediated Killing (R21 Clinical Trial Not Allowed) | PA 19 020

Opportunity Information: Apply for PA 19 020

The National Institutes of Health (NIH) funding opportunity titled "Fc-Dependent Mechanisms of Antibody-Mediated Killing (R21 Clinical Trial Not Allowed)" (Funding Opportunity Number: PA-19-020) supports exploratory, early-stage research aimed at filling key knowledge gaps in how antibodies eliminate target cells through Fc-dependent immune mechanisms. The focus is on understanding how antibodies, through their Fc (constant) region, recruit and direct immune effector functions to kill infected cells, remove abnormal or diseased cells, or therapeutically ablate cell types that drive immune-mediated disorders such as autoimmune and allergic diseases. This is an R21 mechanism, meaning the intent is to encourage innovative, higher-risk ideas and proof-of-concept work rather than large, mature programs, and it explicitly does not allow clinical trials.

Scientifically, the FOA centers on two major Fc-dependent pathways: antibody-dependent cellular cytotoxicity (ADCC) and antibody-dependent cell-mediated phagocytosis (ADCP). ADCC generally refers to the process where immune cells recognize antibody-coated targets and then kill those targets (often through cytotoxic effector cells). ADCP refers to immune cells recognizing antibody-opsonized targets and engulfing and clearing them through phagocytosis. The FOA is seeking applications that clarify the underlying biology of these processes, including what determines whether a target is killed versus cleared, which immune cell types and Fc receptor interactions matter most, how different antibody features influence outcomes, and why these mechanisms can vary across tissues, disease contexts, or experimental systems.

A major emphasis is also placed on practical enablers for the field: the development of tools, technologies, and animal models that make it easier to identify, measure, and evaluate Fc-driven killing mechanisms mediated by human antibodies in vivo. In plain terms, NIH is not only interested in conceptual advances, but also in methods that let researchers reliably test Fc-dependent antibody function in living systems in ways that translate better to human biology. This could include improved assays, engineered model systems, or platforms that help disentangle complex immune interactions that are hard to capture with standard in vitro experiments.

From an administrative standpoint, this is a discretionary grant opportunity in the health category (CFDA: 93.855) administered by NIH. The award ceiling listed is $200,000. The original closing date provided is 2022-01-07, and the FOA was created on 2018-10-05. Because the R21 mechanism is typically used for exploratory research, proposed projects are expected to be targeted, hypothesis-generating, and methodologically creative, rather than requiring extensive preliminary data or delivering late-stage development outcomes. The "Clinical Trial Not Allowed" designation means applicants must ensure their studies do not meet NIH's definition of a clinical trial (for example, prospective assignment of human participants to interventions to assess health-related outcomes).

Eligibility is broad and includes many types of U.S.-based organizations: 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 (including those other than federally recognized tribal governments); public housing authorities/Indian housing authorities; nonprofits with or without 501(c)(3) status (outside of higher education); for-profit organizations other than small businesses; and small businesses. The FOA 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, U.S. territories or possessions, regional organizations, and non-U.S. entities (foreign organizations). This wide eligibility reflects NIH's interest in drawing from diverse research environments and institutional strengths to tackle complex immunological and translational measurement challenges.

Overall, the opportunity is designed to move the field toward a clearer, mechanistic, and more testable understanding of how human antibodies drive Fc-dependent elimination of cells in infection, cancer or other aberrant cell contexts, and immune pathology, while also building the experimental systems needed to evaluate these mechanisms rigorously in vivo.

• The National Institutes of Health in the health sector is offering a public funding opportunity titled "Fc-Dependent Mechanisms of Antibody-Mediated Killing (R21 Clinical Trial Not Allowed)" and is now available to receive applicants.
• Interested and eligible applicants and submit their applications by referencing the CFDA number(s): 93.855.
• This funding opportunity was created on 2018-10-05.
• Applicants must submit their applications by 2022-01-07. (Agency may still review applications by suitable applicants for the remaining/unused allocated funding in 2026.)
• Each selected applicant is eligible to receive up to $200,000.00 in funding.
• 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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