On January 13, 2022, the U.S. Food and Drug Administration (FDA) approved Solensia (frunevetmab), the first monoclonal antibody (mAb) new animal drug approved by the FDA for use in any animal species. Solensia™ is approved for the control of pain associated with osteoarthritis in cats.

Developed by Zoetis Inc., frunevetmab is a felinized immunoglobulin G mAb that targets nerve growth factor. Similar to humanization, felinization is a process in which all regions of a murine antibody are replaced with feline counterparts except for the complementarity-determining regions. Substantial evidence of effectiveness was demonstrated by the results of two field studies in cats with naturally occurring osteoarthritis. The endpoints used to evaluate the effectiveness of Solensia™ were observer-reported measures conducted by either owners (assessment of the cat’s activities before development of osteoarthritis, as well as before and after treatment) or veterinarians (orthopedic examinations before and after treatment).

Solensia™ is given by subcutaneous injection once a month and is dosed by weight range. Cats are given the full contents of 1 or 2 vials based on body weight to target a minimum dose of 1 mg/kg. Each vial contains 7 mg of frunevetmab.

At least one other mAb, lokivetmab (Cytopoint), is approved for veterinarian use in the US.  Manufactured by Zoetis, the product is used to treat atopic dermatitis in dogs, but it was approved by the US Department of Agriculture, not FDA. More information on FDA’s Center for Veterinary Medicine and the New Animal Drug Application (NADA) process can be found here.