Risk requirements eased for ProHeart 6 injectable heartworm control

After conducting a 4.5-year-long safety review of ProHeart 6 (moxidectin), an injectable heartworm preventive for dogs administered every six months, Zoetis has announced the lifting of several safety restrictions imposed in 2008 by the U.S. Food and Drug Administration (FDA).

The changes, which are part of the product’s updated risk minimization plan (RiskMAP) with the FDA, are as follows:

> The product may be used in healthy dogs 6 months to 7 years of age.

> The product may be administered by a trained, certified veterinary technician or assistant.

> Clients are no longer required to sign a consent form before administration.

ProHeart 6 has had a rocky history since its launch to the U.S. veterinary market in the early 2000s. After thousands of adverse events, including death, were reported to the FDA in association with administration, the product was pulled from the U.S. market in 2004. The manufacturer at the time, Fort Dodge Animal Health, began conducting studies to evaluate the product’s safety profile and investigate the adverse events.

According to the FDA, these studies suggested that some residual solvents used in manufacturing were allergenic, prompting Fort Dodge to change how the drug was manufactured. After these changes were made, adverse event reports declined in overseas markets and the product was relaunched in 2008 to the U.S. veterinary market.

However, a number of new rules constituting the original RiskMAP program accompanied the 2008 relaunch. Veterinarians were required to complete in-depth training, read the new label, restrict treatment to healthy dogs between the ages of 6 months and 7 years of age, provide dog owners with a client information sheet, obtain signed informed consent, record the product lot number in the medical record, and report adverse events.

Since then, Fort Dodge was acquired by Pfizer Animal Health, which was subsequently spun off as an independent, publically held company, Zoetis Inc. Also, studies of ProHeart 6 have continued, leading to today’s announcement of the less-restrictive RiskMAP. “A steady and dramatic increase in ProHeart 6 use occurred during this 4½-year period, with ProHeart 6 demonstrating predictable safety and efficacy that remained consistent as use increased,” reads an Aug. 28 release from Zoetis. “These data show that ProHeart 6 is a safe and effective product for the prevention of canine heartworm disease for six full months in dogs age 6 months and older.”

“We are very pleased that the predictable performance of ProHeart 6 has made revisions to the RiskMAP appropriate at this time,” says Zoetis’s J. Michael McFarland, DVM, DABVP, group director of companion animal veterinary operations. “Although significant restrictions have been lifted, Zoetis remains committed to education on the proper use of ProHeart 6 and will continue to uphold the guidelines set forth by the FDA to help assure that veterinarians and, through them, pet owners are aware of the benefits and risks of this product.”

To obtain additional information, including a copy of the product labeling or full prescribing information, visit ProHeart6dvm.com or call (888) 963-8471.