By Pat Anson, PNN Editor
The United States Food and Drug Administration has approved a new drug to treat osteoarthritis pain in cats, the first monoclonal antibody approved by the FDA for use in any animal. The same type of drug has been rejected for use in humans due to safety risks.
Solensia (frunevetmab) is an injectable monoclonal antibody manufactured by Zoetis which targets nerve growth factor (NGF), a protein that increases in animals and humans due to injury, inflammation or pain. Solensia is designed to bind to NGF and block pain signals from reaching the brain.
Osteoarthritis (OA) is a progressive joint disorder that leads to cartilage thinning and joint damage. Feline osteoarthritis is a common condition in older cats, but treatment options for them are limited, as they are for humans.
“Advances in modern veterinary medicine have helped extend the lives of many animals, including cats. But with longer lives come chronic diseases, such as osteoarthritis,” said Steven Solomon, DVM, director of the FDA’s Center for Veterinary Medicine.
“Today’s approval marks the first treatment option to help provide relief to cats suffering from this disease and can significantly improve their quality of life. We also hope that today’s approval of the first monoclonal antibody by the FDA for all animal species will expand research. and the development of other monoclonal antibody products to treat animal diseases.”
Safety Issues with NGF Inhibitors
Last year, the FDA refused to approve tanezumab, a monoclonal antibody and NGF inhibitor, as a treatment for osteoarthritis in humans after two of its advisory boards said the drug accelerated damage. arthrosis joints. Rapidly progressive osteoarthritis (RPOA) was so severe that some patients in clinical trials had to stop taking the drug and required total joint replacements.
The side effects of NGF inhibitors have been known for over a decade. The FDA slowed development of NGF inhibitors in 2010 due to concerns that they worsen osteoarthritis in some patients. But under pressure to approve more nonopioid painkillers, the FDA allowed clinical studies of tanezumab to resume in 2015.
Eli Lilly and Pfizer invested heavily in tanezumab research, but ended their joint development of the drug in 2021 after the FDA and European Medicines Agency said they would not approve tanezumab for humans due to security issues.
In A press release announcing Solensia’s approval for cats, the FDA makes no mention of RPOA in its list of side effects, which include vomiting, diarrhea, injection site pain, crusting, dermatitis and itchy skin. The statement said side effects were mild and did not require discontinuation of treatment during observational animal studies.
In more detailed information from the FDA Freedom of Information Summary for Solensia, the agency said “RPOA has not been characterized or reported in cats,” but has this stern warning for humans administering the drug:
“Pregnant, potentially pregnant or breastfeeding women should exercise extreme caution to avoid accidental self-injection of Solensia. It is well established that NGF is important in the normal development of the fetal nervous system, and laboratory studies in non-human primates have shown that human anti-NGF mAbs can cause reproductive and developmental toxicity. Fetal abnormalities, increased stillbirth rate, and increased postpartum fetal mortality have been observed in rodents and non-human primates receiving anti-NGF mAbs.
Solensia is not recommended for pregnant or nursing cats. It will only be available with a prescription from a licensed veterinarian who administers the injection monthly.
“The approval of Solensia is a significant step forward in the control of pain related to feline osteoarthritis. Cat owners and veterinarians can be confident that Solensia, with the active ingredient frunevetmab, a monoclonal antibody (mAb) designed specifically for felines, has been studied and shown to control osteoarthritis pain and help cats move more freely again,” Mike McFarland, DVM, Chief Medical Officer of Zoetis, said in A declaration.
The use of Solensia in cats was aapproved by the European Medicines Agency Last year. The drug is expected to be available to US veterinarians in the second half of 2022.