Potency Assessment of Active Immunotherapy Products August 2026

GUIDANCE DOCUMENT

Submit Comments by 11/18/2026

Submit Comments Online

Although you can comment on any guidance at any time (see 21 CFR 10.115(g)(5)), to ensure that the FDA considers your comment on a draft guidance before it begins work on the final version of the guidance, submit either online or written comments on the draft guidance before the close date.

If unable to submit comments online, please mail written comments to:

Dockets Management
Food and Drug Administration
5630 Fishers Lane, Rm 1061
Rockville, MD 20852

All written comments should be identified with this document's docket number: FDA-2026-D-8561

---

• Docket Number: FDA-2026-D-8561
• Issued by: Center for Biologics Evaluation and Research, Office of Therapeutic Products

For a high-level overview of this guidance document, please watch this recorded webinar featuring Ramjay Vatsan, PhD from FDA’s Office of Therapeutic Products.

This guidance document provides recommendations for developing assays  to assess potency  as a part of a potency assurance strategy for active immunotherapy products (ACTIMPs) .  Active immunotherapies aim to treat a pre-existing disease or condition by inducing, stimulating, or modulating immune effector cells through introduction of an antigen (or antigens) associated with that disease or condition to the immune system.  This guidance does not apply to preventive vaccines for infectious disease indications, bacteriophage products for infectious diseases, live biotherapeutic products, fecal microbiota for transplantation (FMT) products or allergenic products.  Considerations related to potential safety concerns associated with ACTIMP product design are outside the scope of this guidance. Sponsors are therefore encouraged to consult with the appropriate product office regarding such matters.

When finalized, this guidance will describe the FDA’s current thinking regarding design, validation, and evaluation of potency tests for ACTIMPs.  This guidance is intended to supplement the guidance for industry, when finalized, on Potency Assurance for Cellular and Gene Therapy Products (Ref. 1) with additional advice and considerations specifically for ACTIMPs, including peptide- and-protein based ACTIMPs that are not cellular or gene therapy products (Ref. 2). 

Questions?