A short rundown of how animal drugs are regulated
I have a bit that I do when people ask me what I do. I say, “I work on drugs for cats!”
Then they say, “What kind of drugs?”
And I say, “Oh, you know, methamphetamine, LSD, those types of drugs.”
This entertains me but sometimes shuts down the conversation. If the conversation continues, however, and I reveal that I’m actually working on therapeutics for serious feline diseases, the conversation often turns to the regulatory environment around animal drugs. People want to know if there’s any regulatory environment at all, or if it’s less strict than the human regulatory environment.
Here are the short answers to those questions:
1. Yes, there is a regulatory environment.
2. Yes, it is less strict than regulation of human drugs, but it’s comparable in terms of what studies you have to run.
For the longer answers, read on.
First of all, with regards to the regulatory environment that exists, I oversimplify by referring to the animal FDA, which is technically known as the Center for Veterinary Medicine, or CVM1. There are actually roughly 5 different regulatory paths for animal drugs with different expectations for each path:
1. Novel small molecule drugs for pets
2. Novel small molecule drugs for livestock
3. Repurposed small molecules for pets or livestock
4. Novel or repurposed small molecules for “minor uses and minor species” or MUMS 2
5. Biologics, including vaccines and monoclonal antibodies, which for historical reasons are regulated by the USDA3
Literally all of these paths are easier than doing human drugs. While you generally have to show safety and efficacy4, you can do a lot of work in your target species, including efficacy studies if you can figure out how to do it ethically. The stricter, IRB-type regulations only come in when you deal with client-owned pets or livestock, but, even still, injuring or killing someone’s pet is not as serious as injuring or killing a person.
The only additional burdens that these regulatory paths can pose that would not be a problem in human drugs is, well, how they’d impact humans. Not only do people sometimes eat the animals that are given drugs (hopefully only if they’re livestock), but even pet animals sometimes poop in humans’ beds or lick their faces. It would be really bad if people got sick from the drugs those animals were taking.
But, overall, developing animal drugs is cheaper and simpler than developing human drugs. The regulators themselves reflect that, too. The animal FDA regulators are, generally, friendlier than the human FDA regulators, and tend to be more “veterinarians who are temporary regulators” than the full-time, professional regulators of the human FDA. This is generally a good thing for drug companies, although the lack of sophistication of the animal FDA can sometimes be a detriment.
This lack of regulation extends to the payer environment, too. Vets can technically prescribe any drug they want to, they usually have their own pharmacy, and almost all veterinary spending (about 85%) is out of pocket by the owner of the animal. So, all the complicated bits of dealing with insurance, pharmacy benefit managers, and Medicare are thrown out of the window.
Unfortunately, this also impacts revenue. There’s only so much people can pay out of pocket (or are willing to for their animals), and animal drugs that cost more than, say, $10k/year are still so niche as to be almost non-existent. My rule of thumb is that drugs developed for animals cost 10x less than their comparable drugs in humans, but also they make 10x less in revenue.
And that’s my super short rundown of the animal regulatory environment. I tried not to get too into the weeds, but I thought it’d be helpful to give people a broad overview.
This is similar to how people oversimplify by referring to the FDA as a whole, when, actually, the FDA regulates a ton of things, and different departments regulate differently. Even in drugs, it makes a big difference whether your drug ends up being regulated by CDER, which handles normal drugs, or CBER, which handles biologics. Then it can make a big difference which department in the FDA is regulating your drug, because the Division of Neurology is a very different vibe than the Division of Oncology.
This is actually a super interesting regulatory pathway. If an animal drug treats a rare disease or a minor species, defined as not horses, dogs, cats, cattle, pigs, turkeys, or chickens, and people won’t eat the animal while it’s getting the drug, the drug has a very low bar for getting approved. Often, you don’t need to run any real studies at all. The most common place this path comes up is in aquaculture when dealing with fish fry.
Basically, when the regulatory paths were set up, the only biologics that existed were vaccines for livestock, which the USDA claimed as their territory. Now the world is very different, and the best-selling drugs in animals are pet monoclonal antibodies, but still the USDA holds onto its fiefdom. I haven’t had to deal with the USDA so my information about them is secondhand.
The exceptions are in MUMS, as I explain in footnote 2, and, recently, in drugs which get a “reasonable expectation of effectiveness” nod or RXE. If you successfully argue to the FDA that your animal disease is both important and difficult to run an efficacy trial in, you can get your drug temporarily approved for sale for 4.5 years as you run that efficacy trial. Then, at the end of the 5th year, your drug is either actually approved or pulled off the market. This is a weird pathway, but potentially very lucrative and everyone in the animal health space is watching it. If you’re aware of Loyal, it’s the one that Loyal is going down for its dog aging drug.
That's fascinating. Why doesn't Big Pharma do this so they can test drugs more cheaply? Their drugs are too human centric?