In the fast-growing field of veterinary regenerative medicine, material from cells and tissues — such as living cells, serum, or bone — is used in animals with the hope of repairing diseased or damaged tissues or organs. For example, in a horse with tendonitis, the damaged tendon may heal with scar tissue that isn’t as strong or elastic as the original tendon before it was damaged. The goal is to transplant living cells or other tissues into the injured tendon, hopefully stimulating it to regenerate and heal.
Veterinary regenerative medicine is an active area of research for developing new cell and tissue therapies for animals. Such therapies are called animal cells, tissues, and cell- and tissue-based products, or ACTPs for short. This term refers to products for use in animals that contain, consist of, or are derived from cells or tissues. Examples include animal stem cells, differentiated cells, and tissues such as blood, platelet-rich plasma, and amnion.
ACTPs are intended to be implanted, transplanted, infused, or transferred from a donor into an animal recipient. Sometimes the donor and recipient are the same animal. Sometimes the donor and recipient are different animals of the same species. And other times, the donor and recipient are different species.
Most ACTPs are Animal Drugs
Most ACTPs meet the legal definition of “drug” because they are intended to treat, control, or prevent a disease or other condition — such as osteoarthritis — or to affect the structure or function of the body — such as improving fertility. Therefore, FDA regulates these products as animal drugs. The same laws and regulations that apply to other animal drugs also apply to ACTPs. FDA must review and approve these products before companies can legally market them.
The pre-market review is integral to FDA’s ability to protect animal and public health. During the review, the agency evaluates information submitted by the company to make sure the animal drug is safe and effective for its intended use and that the drug is properly manufactured and adequately labeled and packaged. If FDA determines that the data show the animal drug is safe, effective, and high-quality, the agency approves the drug for the uses listed on the label.
Unapproved Animal Drugs
An ACTP that meets the legal definition of a drug but is marketed without FDA approval is an unapproved animal drug. It is illegal to market an unapproved ACTP because it hasn’t gone through the required FDA pre-market review and approval process. Unapproved ACTPs may not be safe, effective, properly manufactured, or adequately labeled or packaged. Currently, no ACTPs are FDA-approved.
FDA recognizes that certain ACTPs, while unapproved, pose a lower risk to human and animal safety than other categories of ACTPs. The agency intends to prioritize use of its resources for certain ACTPs in a manner that is protective of human and animal health, based on risk, and informed by available science and data. FDA provides a publicly available list of those ACTPs that the agency has determined are lower risk following a review of product-specific information.
Navigating the Approval Process
FDA is committed to helping those involved in the manufacturing of ACTPs navigate the approval process. The agency understands the need to have safe and effective ACTPs approved and available for use in animals and has taken several actions to encourage the development of these products.
FDA has issued several guidance documents to help developers of ACTPs better understand the regulatory process and associated approval requirements; conducted outreach by presenting at public scientific conferences and publishing web resources about the regulatory process for ACTPs; provided a letter to universities and veterinarians on the development of ACTPs; and started the Veterinary Innovation Program for developers of animal biotechnology products, including ACTPs. For more information on the review process, please see Cell and Tissue Products for Animals.
Clinical Field Studies
FDA keeps a list of current clinical field studies that are investigating the use of ACTPs in animals. (A clinical field study is a type of research study that tests how well a new medical product works in animals.) The companies conducting these studies have given FDA permission to include their studies in the publicly available list, which includes information about the condition being studied and in which species. FDA’s list is publicly available and includes information about the condition being studied and in which species. Depending on the study, enrolled animals may be pets, such as dogs and cats, or food-producing animals, such as cattle and pigs. There is also contact information for each study, so the public can find out further information.
Great Promise but Proof Needed
In recent years, the scientific community has made significant advances in developing ACTPs, and scientists continue to research these innovative therapies. Veterinary regenerative medicine holds great promise for future safe and effective treatments for many animal diseases and other conditions. However, the ultimate proof rests in obtaining high quality data from well-conducted, well-controlled, and well-designed scientific studies. The results of these studies will help FDA, veterinarians, animal owners, and developers of ACTPs better understand the potential benefits and risks of these products.
Because of the novelty and complexity of ACTPs, FDA encourages individuals, universities, and companies interested in developing these products to contact the agency at AskCVM@fda.hhs.gov.