Wyeth isn't have great luck getting the FDA to approve its drugs for humans, but dogs are another matter. The agency is allowing a limited return of a reformulated version of ProHeart 6, a heartworm med for Fido that was yanked four years ago after being linked to an unusually high rate of deaths and serious side effects - lethargy, vomiting, seizures, difficulty walking, jaundice, bleeding disorders, allergies, and convulsions. With drugs like that, who needs disease?
The new version is an injectable and will be available on a restricted basis under a so-called 'risk minimization' program, in which vets must register and participate in an Internet training program. This is a first for a veterinary drug, says Bernadette Dunham, who heads the FDA’s Center for Veterinary Medicine, in a statement. “While we concur with the limited return of ProHeart 6 to the US market, we strongly encourage veterinarians and pet owners to report any possible adverse reactions.”
Wyeth has worked hard for this moment, but not without enduring a series of embarassments that also spoke poorly of the FDA. In 2003, an FDA vet named Victoria Hampshire began examining a growing number of adverse reactions to ProHeart 6, which was ultimately withdrawn based on her reports.
But then, Wyeth launched a secret investigation into Hampshire; raised conflict-of-interest charges against her at the FDA; and implicitly threatened agency officials that further action would be pursued if Hampshire was allowed to remain in place. Among those involved in a failed effort to allow ProHeart 6 back on the market was former Wyeth ceo Bob Essner. Hampshire transferred to a different FDA job, but the episode was investigated and publicized by US Senator Chuck Grassley.
The FDA says the return of the infamous med is based on results of additional toxicological and pharmacologic studies by Wyeth's Fort Dodge Animal Health units, along with the "low adverse reaction frequency" in international markets.
After the 2004 withdrawal, the FDA says, Wyeth conducted additional tests showing residues of solvents used to make ProHeart 6 may cause allergic reactions. So Wyeth has improved manufacturing specs to decrease the residues, the FDA says, and has marketed the product in international markets, where few adverse events have been reported with the reformulated version.
UPDATE: Grassley, who is the ranking Republican on the Senate Finance Committee, today wrote a letter to the FDA seeking info about how the agency went about approving the new version of ProHeart 6. Among his concerns - whether Wyeth submitted studies that used guinea pigs. Here is his letter.
ANOTHER UPDATE: Victoria Hampshire calls us to say she has concerns. "I'd like to know how the FDA will enforce the process...If (Wyeth) is willing to go that extent to discredit a safety officer it raises questions about how the FDA can enforce restrictions on veterinarians...And given the way the whole matter was handled by the CVM, there should have been a public meeting before the approval."