It's official: ProZinc’s not just for cats anymore.

The US Food and Drug Administration (FDA) announced last week that it had approved ProZinc for the treatment of hyperglycemia and clinical signs associated with hyperglycemia in dogs with diabetes mellitus (DM).

ProZinc (protamine zinc recombinant human insulin) is manufactured by Boehringer Ingelheim Animal Health, Incorporated (BI), and was FDA approved for use in treating feline DM in 2009.

While veterinarians have been using ProZinc to treat canine DM for years under extralabel use (see the 2018 AAHA Diabetes Management Guidelines for Dogs and Cats), this marks the first time that the drug has been officially sanctioned by the FDA for treating DM in dogs.

Although ProZinc is made from recombinant DNA sourced from the human insulin gene, the drug has not been evaluated for use in humans.

276 dogs received ProZinc during a 182-day clinical field study. Effectiveness was based on successful control of DM, which was defined as improvement in at least one laboratory parameter (blood glucose curve mean, blood glucose curve minimum, or fructosamine) and at least one clinical sign (polyuria, polydipsia, or weight loss).

Based on this definition, 162 of 224 cases (72%) were considered successful.

Among the most common adverse reactions were lethargy, vomiting, seizures, shaking, diarrhea, and ataxia. ProZinc is contraindicated in dogs sensitive to protamine zinc recombinant human insulin or any other ingredients in ProZinc, and during episodes of hypoglycemia.

ProZinc joins Merck Animal Health’s Vetsulin (porcine insulin zinc suspension) as one of only two drug products specifically approved by the FDA for the management of DM in dogs.

NEWStat asked Patty Lathan, VMD, DACVIM, if the appearance of a second FDA-approved insulin therapy for canines will change the way veterinarians treat DM in dogs.

Lathan, associate professor of small-animal internal medicine at Mississippi State University’s College of Veterinary Medicine, and a member of AAHA’s Diabetes Management Task Force, said, “It’s great that BI has committed the resources toward getting ProZinc FDA approved for use in dogs. There was a study that showed its efficacy in dogs in 2012, and I used it successfully in a Chihuahua that I could not get regulated on [non-FDA-approved] NPH insulin when Vetsulin was unavailable.”

But Lathan says it’s too soon to say if the new player on the FDA-approved insulin scene is going to be a gamechanger, although having a choice is definitely a good thing.

“Every dog reserves the right to respond to insulin however he or she feels fit, and not all dogs are easy to regulate with Vetsulin,” said Lathan. “So having the option to switch to another FDA-approved insulin that’s already on their [hospital] shelves is great.”

Ellen Behrend, VMD, PhD, DACVIM, another member of AAHA’s Diabetes Management Task Force, agrees with Lathan that having the choice is a good thing, but can’t say how it's going to affect protocols that individual veterinarians have in place currently.

Behrend, a professor in the Department of Clinical Sciences at theAuburn University College of Veterinary Medicine , told NEWStat, “I’m not sure [FDA approval] will have a big impact. My guess is that those [who] want to use [ProZinc] will have been using it extralabel already.”

Nonetheless, Behrend is impressed with BI’s accomplishment. “I do applaud any company that gets a veterinary drug FDA approved.”

Photo credit: © iStock/FSTOPLIGHT