Botulinum Toxin Potency Assay using Tissue Chips (BoT PATCh) (U43/U44 - Clinical Trail Not Allowed) | RFA TR 22 032

Opportunity Information: Apply for RFA TR 22 032

The Botulinum Toxin Potency Assay using Tissue Chips (BoT PATCh) funding opportunity (RFA-TR-22-032) is an NIH Small Business Innovation Research (SBIR) cooperative agreement aimed at moving botulinum toxin potency testing away from the traditional LD50 mouse lethality bioassay (often called the mouse lethality bioassay, or MLB). The central purpose is to support the development, regulatory qualification, and commercialization of new approach methodologies (NAMs) that use neuromuscular junction (NMJ) tissue chip platforms as an alternative potency assay for botulinum toxin. In practical terms, the program is pushing for a modern, biology-relevant, potentially more reproducible and humane test system that can ultimately replace an animal lethality test that has long been used for lot release and potency determination.

A key feature of the opportunity is the explicit partnership between NIH (specifically NCATS) and the FDA. Rather than funding being purely hands-off, the award is structured as a cooperative agreement (U43/U44), meaning the government expects active collaboration with recipients. The intent is for NIH and FDA staff to work directly with funded small businesses to coordinate technical progress, align the assay with regulatory expectations, and shape the evidence package needed for acceptance. This collaborative model is designed to reduce the common gap between promising lab methods and methods that regulators and industry can actually rely on for high-stakes decisions such as potency measurement.

The program goal is to establish BoT PATCh as a Drug Development Tool (DDT). That matters because DDT status is tied to a formal regulatory framework in which a tool, method, or assay is supported by a defined context of use and a robust validation plan, making it easier for sponsors to adopt the tool with confidence in how FDA will interpret the resulting data. Within that DDT framing, the FOA emphasizes positioning the tissue-chip-based assay as a stand-alone replacement for the MLB, not merely a supplementary or partial alternative. That indicates applicants should be thinking beyond proof-of-concept and toward the kind of analytical validation, performance characterization, reproducibility testing, and cross-site transferability that would be required for the method to function independently in real-world potency testing.

Because it is an SBIR cooperative agreement, eligibility is limited to U.S. small business concerns. Foreign institutions are not eligible, non-U.S. components of U.S. organizations are not eligible, and foreign components are not allowed. The funding mechanism is U43/U44, which typically aligns with phased development (with U43 often corresponding to an initial phase and U44 to a subsequent phase), and the FOA explicitly notes that clinical trials are not allowed. The work is therefore intended to be preclinical and method-focused: building the assay platform, demonstrating performance, defining and executing validation plans, and advancing toward a commercially viable product or service that can be used broadly by developers and manufacturers of botulinum toxin products.

Administratively, the opportunity is a discretionary funding program under the NIH with CFDA numbers 93.350 and 93.853. The original closing date listed is 2023-08-21, and the FOA was created on 2022-09-19. While the summary information provided does not specify an award ceiling or expected number of awards, the thrust of the program is clear: fund U.S. small businesses to develop NMJ tissue-chip potency assays for botulinum toxin, work side-by-side with NIH and FDA on the final validation strategy, and generate the level of evidence needed to qualify the approach as a DDT so it can credibly replace the longstanding LD50 mouse lethality assay.

• The National Institutes of Health in the health sector is offering a public funding opportunity titled "Botulinum Toxin Potency Assay using Tissue Chips (BoT PATCh) (U43/U44 - Clinical Trail Not Allowed)" and is now available to receive applicants.
• Interested and eligible applicants and submit their applications by referencing the CFDA number(s): 93.350, 93.853.
• This funding opportunity was created on 2022-09-19.
• Applicants must submit their applications by 2023-08-21. (Agency may still review applications by suitable applicants for the remaining/unused allocated funding in 2026.)
• Eligible applicants include: Small businesses.

Apply for RFA TR 22 032

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