FDA Conditionally Approves First Drug to Fight New World Screwworm in Cattle
WASHINGTON – The Food and Drug Administration (FDA) has granted conditional approval to Dectomax-CA1, a doramectin injection, for both the treatment of and 21-day prevention of infestations caused by larvae of Cochliomyia hominivorax, commonly known as New World screwworm, in cattle. The approval, announced September 30, addresses an urgent need for tools to combat the parasite’s spread, according to the FDA.
“We understand the urgency with which America’s farmers and ranchers are asking for tools to fight New World screwworm,” FDA Commissioner Martin Makary stated in a press release.
New World screwworm larvae burrow into the flesh of animals, feeding on living tissue and impacting livestock, pets, wildlife, and, rarely, people.
Dectomax-CA1 is an over-the-counter injectable solution available in 250 mL and 500 mL multi-dose vials. The dosage is 1 mL (10 mg doramectin) per 110 lbs of body weight (200 mcg/kg) administered via subcutaneous or intramuscular injection in the neck region.
The drug contains the same active ingredient and dosage as fully approved Dectomax,currently used for treating other parasites in cattle and swine. The withdrawal period for cattle treated with Dectomax-CA1 is 35 days, consistent with Dectomax. it is indeed not approved for use in dairy cattle aged 20 months or older or veal calves to prevent drug residues.
According to Timothy Schell, acting director of the FDA Centre for Veterinary Medicine (CVM), the agency determined the drug is safe with “a reasonable expectation of effectiveness.” It is promptly available while sponsor Zoetis gathers data for full approval.
“The FDA will continue to expedite review of animal drugs to help the U.S. fight this devastating threat to our nation’s livestock and the livelihoods of the farmers and ranchers who care for them,” Schell said.
The conditional approval follows a reported human case of travel-associated New World screwworm in August and the parasite’s detection fewer than 70 miles south of the U.S.-Mexico border in late September, prompting increased veterinary vigilance.
Further data is available on the FDA’s website: https://www.fda.gov/animal-veterinary/safety-health/new-world-screwworm-information-veterinarians. The FDA CVM has also provided information on other drugs veterinarians may consider using extralabel for cattle and other species, including dogs and cats.
