Yesterday, the U.S. Food and Drug Administration’s Center for Veterinary Medicine (CVM) published final Guidance for Industry (GFI) #299 “Dual Labeling for Fully Approved and Conditionally Approved New Animal Drugs with a New World Screwworm-Related Indication.” GFI #299 applies to drugs that are fully approved under section 512 of the Federal Food, Drug, and Cosmetic Act (FDCA) (21 U.S.C. § 360b) and that are also conditionally approved[1] under FDCA section 571 (21 U.S.C. § 360ccc). It provides guidance to marketing authorization holders (MAHs) seeking to combine fully and conditionally approved indications on a single new animal drug product label and in the drug’s labeling (dual labeling).
GFI #299 explains that CVM interprets FDCA section 571(f)(2), which provides, “[t]he Secretary shall, through regulation or guidance, determine under what conditions an intended use that is the subject of a conditional approval under this section may be included in the same product label with any intended use approved under section 360b of this title,” as permitting CVM’s determination that the label and the labeling of a product that is both fully and conditionally approved may be dual labeled. CVM intends to issue future guidance addressing more broadly the conditions under which dual labeling would be permissible, but is issuing this guidance now to address products with indications for New World screwworm (Cochliomyia hominivorax) (NWS). CVM is implementing this guidance without first seeking public comment because it has determined that prior public participation is not feasible or appropriate in light of the significant potential for a public health emergency associated with NWS.[2]
NWS is a parasitic fly that lays eggs in and on open wounds and mucous membranes and can infest livestock, pets, wildlife, birds, and (rarely) humans. NWS has been eradicated from North and Central America for decades, but has been progressing north for the past several years and is now approaching the U.S. southern border. It poses a threat to livestock and food security, potentially impacting national security and animal health.[3]
On September 30, 2025, FDA conditionally approved under FDCA section 571 Dectomax®-CA1 (doramectin) injectable, CNADA 141-616, for prevention and treatment of infestations caused by NWS larvae, and prevention of reinfestation for 21 days in cattle.[4] Zoetis Inc., the MAH of CNADA 141-616, is also the MAH for Dectomax® (doramectin) Injectable Solution for Cattle and Swine, NADA 141-061, which is fully approved under FDCA Section 512(b) for, among other indications, the treatment and control of certain nematode and arthropod parasites in cattle and swine.[5]
GFI #299 provides guidance on adverse drug experience (ADE) reporting procedures for ADEs related to the fully approved indications and those related to the conditionally approved indications, as well as for those ADEs with uncertain attribution. The guidance also addresses reports of product/manufacturing defects and periodic drug experience reports for the NADA and the CNADA approvals.
Stakeholders can submit comments at any time, even following finalization of the guidance, to https://www.regulations.gov/, Docket No. FDA-2025-D-4500 for “Dual Labeling for Fully Approved and Conditionally Approved New Animal Drugs With a New World Screwworm-Related Indication.”
If you have any questions concerning the material discussed in this client alert, please contact the following members of our Animal Food and Drug practice.
[1] Conditional approval means that CVM has determined the drug is safe and has a reasonable expectation of effectiveness. Conditionally-approved animal drugs may remain on the market for one year while the marketing authorization holder (MAH) makes progress toward proving substantial evidence of effectiveness to support full approval. The MAH can ask CVM to renew the conditional approval annually for up to four more years, for a total of five years of conditional approval. If the drug is not fully approved at the end of that time, it must be removed from the market.
[2] 90 Fed. Reg. 48313, 48314 (Oct. 16, 2025).
[3] Id.
[4] https://animaldrugsatfda.fda.gov/adafda/app/search/public/document/downloadFoi/17486.
[5] https://animaldrugsatfda.fda.gov/adafda/views/#/home/previewsearch/141-061.