Microbial-based Cancer Therapy -Bugs as Drugs (R21 Clinical Trial Not Allowed) | PAR 19 194

Opportunity Information: Apply for PAR 19 194

The NIH funding opportunity titled "Microbial-based Cancer Therapy - Bugs as Drugs (R21 Clinical Trial Not Allowed)" (PAR-19-194) is aimed at jump-starting early-stage, high-impact research on using microorganisms as anticancer therapies, particularly in situations where standard treatments tend to fall short. The program is especially interested in difficult-to-treat settings such as poorly vascularized and hypoxic solid tumors, tumor regions that are hard for drugs to reach, dormant or slow-cycling cancer cells that resist therapies designed for rapidly dividing cells, and brain tumors where delivery barriers and the tumor microenvironment often limit current options. The core idea is to push forward innovative "microbe-as-therapy" concepts that can either act directly against tumors or work alongside existing treatments to improve outcomes.

A central focus of the FOA is understanding and leveraging the biology of non-viral microorganisms in cancer, including bacteria, archaebacteria, bacteriophages, and other non-virus microbes. NIH is looking for projects that dig into the mechanisms behind the complex three-way relationship among the microorganism, the tumor, and the immune system. That means proposals should not treat the microbe as a simple tool or payload carrier in isolation, but instead explore how microbial behavior, tumor biology, and immune responses influence each other. Studies can include how microbes localize to tumors (including hypoxic regions), how they survive or are cleared, what immune pathways they activate or suppress, and how those immune changes affect tumor growth or tumor immune evasion.

Another major theme is using microorganisms as delivery vehicles for cancer treatment. This can include engineering or selecting microbes that can carry therapeutic payloads, express anticancer molecules in the tumor microenvironment, or help concentrate treatment where it is needed while limiting systemic toxicity. The FOA also explicitly encourages approaches that complement or synergize with established cancer therapies, which could involve pairing microbial therapies with chemotherapy, radiotherapy, immunotherapies, or other modalities, so long as the proposed work remains in the basic mechanistic or preclinical space. The intent is to advance the preclinical development pipeline for microbial-based anticancer agents by producing convincing mechanistic insight and animal or cell culture evidence that supports future translational steps.

The research scope is limited to basic mechanistic studies and preclinical work in cell culture and animal models, reflecting the "Clinical Trial Not Allowed" designation. Applicants are expected to propose state-of-the-art projects that meaningfully advance knowledge or development readiness, whether the work is hypothesis-driven, discovery-driven, design-directed, or developmental. Strong applications are likely to take an integrative approach, tying together microbial genetics or physiology, tumor microenvironment features, and immune mechanisms to explain not only whether a microbial strategy works, but why it works and under what conditions it might fail.

A key requirement is that proposed projects must address both sides of the equation: the microbial component and the tumor component. In practical terms, NIH is signaling that applications should not be solely about microbial engineering without a serious tumor biology plan, and likewise should not be purely tumor immunology studies without a substantive microbial therapeutic angle. Because these questions span multiple technical domains, the FOA emphasizes multidisciplinary collaboration, encouraging teams that combine expertise from fields such as microbiology, oncology, immunology, and cellular and molecular cancer biology. The goal is to build collaborative efforts capable of tackling complex microbial-tumor-immune interactions with the right experimental models, analytical tools, and conceptual frameworks.

This opportunity uses the R21 mechanism, which typically supports exploratory, early-stage projects designed to generate compelling preliminary data or prove feasibility. The listed award ceiling is $200,000. The agency is the National Institutes of Health, and the program is associated with CFDA numbers 93.395 and 93.396. Eligibility is broad and includes many types of organizations: state, county, and local governments; public and private institutions of higher education; federally recognized tribal governments and other tribal organizations; public housing authorities and Indian housing authorities; nonprofits with or without 501(c)(3) status; for-profit organizations (other than small businesses) as well as small businesses; and other categories. The FOA also highlights additional eligible applicant groups such as HBCUs, Hispanic-serving institutions, tribally controlled colleges and universities, Alaska Native and Native Hawaiian serving institutions, AANAPISIs, faith-based or community-based organizations, eligible federal agencies, regional organizations, US territories or possessions, and even non-US (foreign) entities.

Overall, the grant opportunity is designed to grow the scientific and preclinical foundation for "bugs as drugs" cancer strategies by funding innovative, multidisciplinary projects that explain mechanisms, demonstrate preclinical promise, and clarify how microbial therapies might be developed to reach and treat tumors that are currently poorly served by conventional approaches.

• The National Institutes of Health in the education, health sector is offering a public funding opportunity titled "Microbial-based Cancer Therapy -Bugs as Drugs (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): 93.395, 93.396.
• This funding opportunity was created on 2019-02-22.
• Applicants must submit their applications by 2022-02-17. (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.

Apply for PAR 19 194

[Watch] Creating a grant proposal using the step-by-step wizard inside the applicant portal: