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When Are Animals Necessary for Drug Licensing?


funny rat We predict that in the year 2050 there will be no animal experimentation.  That includes animal testing for drug licensing.  Today, 100 million animals are used in experiments, about 13% of those are involved in studies that are required to license drugs.

Happily, a large step toward the goal of providing alternatives to terminal animal studies was published recently.  The FDA commissioner Scott Gottlieb, MD, stated that the FDA is trying to reduce, replace, or refine the use of animals in research. This is heartening news. We hate the current standards for new drug development that require euthanizing animals in studies. Even if a drug is commonly used in other species—if a new indication is under investigation, terminal studies are required. We’ve repeatedly argued against this position.  We lost the debates. But FDA is not insensitive to the issue.

On the horizon are simulation models that include in vitro (non-animal) dissolution tests and computer modeling that will replace animals in some studies.   A first step to animal-alternative testing is the validation of simulation methods designed to show the equivalence of a proposed generic formulation to an approved drug. We can predict a future that allows these same models for new drug development.  Currently, FDA requires data to understand how a drug performs in a live animal.  In our case, mountains of data obtained from goats and dogs and cats won’t substitute for horses.

A part of the generic licensing process involves an animal drug developer to perform “bioequivalence studies”.  These live animal studies compare the originally approved product and a proposed generic version to see if they are similar enough to link them in terms of safety and effectiveness. These are expensive studies and these studies are ignored by compounders.  Another subject for another day.

Back to the good news. There are studies afoot at FDA that will create a physical model to simulate properties of a specific drug when tested in live animals. The proposed studies use dogs. The live animal data will validate the simulations for anti-parasite formulations that are currently used in dogs.  If the studies are successful, animal drug sponsors may use these data to aid in designing in vitro studies.  And that will save the lives of animals.  The initial studies used to equate the simulation to the live animal are designed to use a small number of anima.  The animals are subjected to minimally invasive procedures, perhaps as simple as a blood draw. And more good news, the lab-dogs will be adopted as pets.

The FDA is encouraging drug companies to develop and validate alternatives to animal testing, including in vitro dissolution tests and computer modeling. For now some drugs may still require live animal studies, and these studies may require euthanizing the test subjects to support a new animal drug. We’d like to get back to the future.  We developed a simulation method that is designed to test the equivalence of a proposed generic anti-protozoal medication against approved drugs.  As licensed EPM drugs age out of patents there will be an opportunity for licensed generics. We are refining an animal model that can prevent excessive horse use and will design and test the validation parameters.  I suspect that it will take a year or so to get the rubber stamp on a validated model.  We would like to be instrumental in the movement to decrease animal experimentation.