US FDA: CLiK Extra Screwworm EUA for New World Myiasis Prevention

• The FDA has issued an Emergency Use Authorization (EUA) for CLiK Extra (dicyclanil topical suspension) wound spray to prevent New World screwworm (NWS) infestations.
• This emergency use authorization animal drug is approved for use on sheep, cattle, goats, swine, camelids, and specific captive and captured wildlife species.
• CLiK Extra acts as an insect growth regulator, disrupting larval development rather than killing existing NWS larvae, and is available over the counter.
• The EUA is temporary and strictly for prevention associated with wounds, birth, or post-surgical/husbandry procedures, not for treating existing infestations.
• The authorization aims to protect both agricultural livestock and wildlife, recognizing the broad impact of NWS beyond farm environments.

This authorization for CLiK Extra (dicyclanil topical suspension) is an Emergency Use Authorization, meaning the product is not formally approved or conditionally approved by the FDA for any indication under standard regulatory pathways.

The U.S. Food and Drug Administration recently issued an Emergency Use Authorization (EUA) for CLiK Extra, a dicyclanil topical suspension wound spray. This authorization permits the use of the product for the prevention of New World screwworm (NWS) infestations, also known as myiasis, across a wide array of animal species. The authorized application is specifically for use on or around wounds.

CLiK Extra is intended for various livestock, including sheep, cattle, goats, and swine, as well as camelids such as camels, llamas, and alpacas. The scope of this emergency use authorization animal drug also extends to specific captive and captured wildlife species, encompassing cervids like deer and elk, American bison, bighorn sheep, and Sonoran pronghorn. This broad application highlights the FDA's comprehensive approach to combating the pest.

Unlike treatments that kill existing larvae, this New World screwworm prevention drug functions as an insect growth regulator. It works by disrupting the developmental cycle of NWS larvae, effectively halting their progression before they can inflict tissue damage on the host animal. The product is available over the counter for topical application and should be applied at the time a wound appears or is created. Should an existing infestation be present, or if one develops post-application, veterinary consultation for treatment options is advised.

This authorization for CLiK Extra (dicyclanil topical suspension) is an Emergency Use Authorization, meaning the product is not formally approved or conditionally approved by the FDA for any indication under standard regulatory pathways. The FDA’s decision was based on a scientific assessment concluding that it is reasonable to believe the CLiK Extra screwworm EUA may be effective for NWS myiasis prevention when used as authorized, and that its known and potential benefits outweigh its known and potential risks.

The EUA strictly limits the use of Elanco US Inc. screwworm spray to prevention associated with wounds, birth, or post-surgical and husbandry procedures, such as dehorning, ear tagging, castration, tail docking, and shearing. This temporary authorization remains effective until it is either revoked by the FDA or the Secretary of the U.S. Department of Health and Human Services terminates the declaration that the NWS public health emergency justifies the emergency use of animal drugs. Adherence to these specific conditions is crucial for livestock screwworm compliance.

Detailed product information, including vital food safety guidelines, is available in the Fact Sheet: Emergency Use Authorization of CLiK Extra (dicyclanil topical suspension) Wound Spray for New World Screwworm (NWS). The FDA, an agency within the U.S. Department of Health and Human Services, is responsible for ensuring the safety and effectiveness of veterinary drugs, among other public health duties.

The FDA's issuance of this emergency use authorization animal drug underscores a proactive stance against a significant agricultural and wildlife threat. Acting FDA Commissioner Kyle Diamantas, J.D., emphasized that this action provides American farmers, ranchers, veterinarians, and wildlife managers with essential tools to combat the pest, stating that the agency would continue its efforts to fight this threatening pest. This sentiment highlights the broad impact of NWS beyond traditional farm settings.

Timothy Schell, Ph.D., director of the FDA’s Center for Veterinary Medicine, further elaborated on the wider implications, noting that the effects of New World screwworm extend beyond the farm gate. Authorizing the dicyclanil topical suspension for captive and captured wildlife species, including bighorn sheep, Sonoran pronghorn, American bison, and cervids, is critical for protecting these animals and preventing their potential contribution to the spread of NWS within the United States. This strategic move aims to safeguard diverse animal populations and mitigate the overall public health emergency presented by NWS.

Lawyers advising agricultural, veterinary, or wildlife management clients should inform them of the availability and specific conditions of this FDA Emergency Use Authorization for CLiK Extra. Compliance officers must ensure the product is used strictly for prevention as authorized, understand its temporary nature, and review the associated food safety information to mitigate potential liability or regulatory issues related to off-label use or product residues.

Source: Original reporting via U.S. Food and Drug Administration