Shares of Phibro Animal Health ($PAHC) have fallen nearly 12% to $24.64 since April 8, when the FDA announced its plans to withdraw its approval of Mecadox (carbadox), an antibiotic for pigs. The agency’s concern is that the drug may leave trace amounts of carcinogenic residue in pork that could pose a cancer risk to people.
Now Phibro is responding to the FDA’s threatened action on Mecadox, which was originally approved in the 1970s. The company issued a statement pointing out that the product was approved--and then granted a supplemental approval in 1998--based on a “rigorous safety review.” The company remains confident in the product’s safety, it said. “After 40 years, carbadox remains a highly effective treatment for controlling bacterial diseases and swine dysentery,” Phibro said in the statement.
In recent years, the FDA has been reaching out to Phibro with questions about whether residues from the antibiotic might persist in pigs’ tissues for longer than initially assumed, according to the company. It responded by launching new studies using “the latest and most sensitive technology available.” Phibro has been providing data from those studies to the agency and expects to complete them within 90 days, at which point it predicts “that the remaining evidence will support the continued safe use of Mecadox.”
The FDA justified its action against Mecadox by stating that there are alternatives to the drug on the market that it feels would pose less of a cancer concern. Those worries about a link between the drug and carcinogenic residues in pork were first raised in 2014, in a report released by the Food and Agriculture Organization of the United Nations and the World Health Organization.
Mecadox has struggled to gain acceptance outside of the U.S. Health Canada banned the product in 2004, just 5 years after the European Union blocked sales of the antibiotic, according to Politico. Several public health organizations have backed the FDA’s decision, including Pew Charitable Trusts and Food Animal Concerns Trust.
Phibro had already faced pressure from a general shift in the market away from antibiotics use in farm animals. In its second fiscal quarter, the company reported a $1.8 million year-over-year drop in sales of medicated feed additives, some of which contain antibiotics.
The company says it will request a hearing to refute the FDA’s reasons for seeking a withdrawal of Mecadox. Meanwhile, Phibro will continue to market it. “We are disappointed that the FDA would take this action when definitive studies are so close to being completed,” it said in the statement.