Ancillary Studies to Ongoing Clinical Projects (R21 Clinical Trial Not Allowed) 2025

The National Institutes of Health (NIH), through the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), has reissued a Notice of Funding Opportunity (NOFO) titled "Ancillary Studies to Ongoing Clinical Projects (R21 Clinical Trial Not Allowed)" under Funding Opportunity Number PAR-25-230. This initiative utilizes the R21 Exploratory/Developmental Research Grant mechanism and is intended to support innovative, time-sensitive ancillary studies that enhance ongoing clinical projects aligned with the NIAMS mission. The goal is to maximize the utility of existing infrastructure, data, and biological samples by supporting exploratory studies that build on ongoing clinical research without conducting clinical trials themselves. The funding opportunity specifically targets ancillary studies that are not part of the parent project but extend its scientific scope by exploring novel hypotheses, mechanisms, or methodologies. Eligible parent projects include publicly or privately funded interventional clinical trials, observational studies, or disease-specific repositories that are actively collecting samples or clinical data. These parent projects must have sufficient resources, including cohorts of well-characterized patients and access to biospecimens or data. Ancillary studies may involve subsets of these cohorts and must not interfere with or overburden the original studies. While investigators submitting to this NOFO may or may not be part of the parent study, collaborations that allow junior researchers to lead projects under senior mentorship are strongly encouraged. Applications must clearly justify the need for accelerated review and demonstrate how the proposed research takes advantage of timely opportunities in the parent study, such as ongoing sample collection or time-bound clinical interventions. Only studies that are time-sensitive and demonstrate clear alignment with NIAMS's research priorities will be accepted. Examples of appropriate research include mechanistic investigations into disease processes, biomarker discovery, sex-based differences in disease progression, or validation of novel measurement methodologies. Applications using only previously collected data or preserved specimens will not be considered responsive and will be returned without review. Funding is limited to a maximum of $400,000 in direct costs over a two-year period, with a cap of $250,000 in any one year. No clinical trials are allowed under this NOFO. Applications must be submitted electronically via NIH ASSIST, Grants.gov Workspace, or institutional systems. The application must include several required documents: a synopsis of the parent project, a one-page statement describing the parent study’s PD/PI and funding source, and a formal letter from a leadership body of the parent study approving the ancillary research and confirming access to required resources. The application must also include a detailed research strategy, timeline, and a specific "Time-Sensitivity Justification" section. Applicants must be registered with SAM.gov, eRA Commons, and Grants.gov, and all PDs/PIs must have valid eRA Commons credentials. Multiple applicant types are eligible, including higher education institutions, nonprofits, for-profits, local and tribal governments, and U.S. territories, though foreign organizations are excluded. Projects involving human subjects must include protections, burden documentation, and appropriate IRB approvals. Key application dates include an opening date of March 9, 2025, with deadlines on April 9, August 6, and December 5, 2025. Letters of intent are due 30 days before each application deadline. The opportunity is expected to expire on December 6, 2025, and is offered on a recurring basis. Review and award cycles are accelerated to accommodate the time-sensitive nature of these studies, with earliest possible start dates ranging from December 2025 to July 2026 depending on the cycle. Contact for scientific inquiries is Dr. Heiyoung Park at parkh1@mail.nih.gov, and for peer review questions, Dr. Kathy Salaita at salaitak@mail.nih.gov. Grants management inquiries can be directed to Teresa N. Do at dote@mail.nih.gov. Interested applicants are strongly encouraged to consult the NIAMS Ancillary Studies FAQ page for additional guidance before applying.

Contact NIAMS staff to confirm R21 suitability. Emphasize innovation and urgency.