Elanco’s Varenzin-CA1 is the first drug for the control of non-regenerative anemia associated with chronic kidney disease (CKD) in cats to be granted conditional approval by the Food and Drug Administration (FDA) the agency announced on May 1. Varenzin-CA1 is available only by prescription from a licensed veterinarian.
CKD is a disease that requires daily management in cats, and non-regenerative anemia is a complication that often contributes to the death or euthanasia of affected cats due to poor quality of life. Cats with CKD develop non-regenerative anemia when their kidneys produce less of a hormone called erythropoietin, which helps the bone marrow make red blood cells.
Current available treatments for non-regenerative anemia in cats with CKD include blood transfusion, iron supplementation therapy, and erythropoietin replacement. However, there are no erythropoietin treatments approved for use in cats. Varenzin-CA1 works by helping to increase the production of erythropoietin in the kidney, which in turn stimulates the bone marrow to produce more red blood cells.
Tracey Forfa, director of the FDA’s Center for Veterinary Medicine (CVM), said in a statement that this is the first drug for cats with expanded conditional approval, “a path to market that encourages the development of innovative treatments and increases choice to treat animals with rare conditions, serious or life-threatening diseases, or diseases without existing or adequate therapies.”
Under conditional approval, the FDA has concluded that the drug is safe for its intended purpose and has a reasonable expectation of being effective. This allows cats with the disease to receive the treatment while full effectiveness data is collected.
The initial conditional approval is good for one year with the potential for four annual renewals. During this time, the animal drug sponsor must demonstrate active progress to demonstrate substantial evidence of effectiveness for full approval. If a sponsor does not meet the substantial evidence of effectiveness requirements at the five-year mark, the product may no longer be marketed.
Expanded conditional approval authority was granted to the FDA in the Animal Drug User Fee Act of 2018 and is intended for drugs that address a serious or life-threatening disease or condition, or an unmet animal or human health need. , and for which demonstrating efficacy would require a complex or particularly difficult study or studies. The expanded conditional approval program will expire in 2028.
Varenzin-CA1 is a liquid that is administered orally to the cat once daily for up to 28 days. Treatment can be repeated as necessary after a minimum break of seven days.
Before prescribing the drug, the FDA says veterinarians should educate cat owners about possible side effects, including vomiting, increased systolic blood pressure, and thromboembolism. The agency also encourages cat owners to work with veterinarians to report adverse events or side effects potentially related to the use of any medication, including Varenzin-CA1.