FDA Approves Monoclonal Antibody to Treat Arthritis in Cats

Solensia (frunevetmab injection) is the first monoclonal antibody drug approved by the FDA for use in any animal species. A monoclonal antibody is a type of protein.

The active ingredient in Solensia is frunevetmab, a cat-specific monoclonal antibody that attaches to a protein called nerve growth factor (NGF) that's involved in pain regulation. When frunevetmab binds to NGF, it prevents the pain signal from reaching the brain, the FDA explained.

"Treatment options for cats with osteoarthritis are very limited. Advancements in modern veterinary medicine have been instrumental in extending the lives of many animals, including cats. But with longer lives come chronic diseases, such as osteoarthritis," said Dr. Steven Solomon, director of the FDA's Center for Veterinary Medicine.

Solensia, marketed by Zoetis, Inc., is available only by prescription from a licensed veterinarian. It's given through injection once a month and the dose is based on a cat's weight.

"Today's approval marks the first treatment option to help provide relief to cats that are suffering from this condition and may significantly improve their quality of life," Solomon said in an agency news release. He said the agency also hopes this approval will expand research and development of other monoclonal antibody products to treat animal diseases.

The FDA's approval of Solensia is based on two studies in which veterinarians assessed cats before and after treatment, and owners reported on their cats' ability to do activities such as jump on furniture, use the litter box or groom themselves.

Overall, cats that received Solensia did better than those that didn't receive the drug.

The most common side effects seen in cats treated with Solensia included vomiting, diarrhea, injection-site pain, scabbing on the head and neck, dermatitis and itchy skin. These effects were relatively mild and did not require a halt to treatment, the FDA said.