December 15, 2015
The U.S. Food and Drug Administration is giving notice that the conditional approval for Kinavet-CA1 (masitinib mesylate) to treat mast cell tumors (a type of cancer) in dogs is no longer in effect as of December 15, 2015. Kinavet-CA1, marketed by AB Science, is now an unapproved animal drug with no legal marketing status and further sales of the drug are illegal.
Only animal drugs intended for minor species, such as ferrets or fish, or for minor uses in a major species, such as to treat certain types of cancer in dogs, may be eligible for conditional approval. To receive a conditional approval, a drug company must prove, among other things, that the animal drug is safe and has a “reasonable expectation of effectiveness” when used according to the label for the conditionally-approved use. Conditional approval allows the drug company to legally sell the animal drug for up to five years. During this period, the company develops and submits to the FDA—and the agency reviews—the necessary data to prove that the drug meets the “substantial evidence” standard of effectiveness for full approval.
Conditional approval does not always lead to full approval. Under the Federal Food, Drug, and Cosmetic Act, a conditional approval is no longer in effect if the FDA does not approve the drug before the conditional approval period terminates. The conditional approval period for Kinavet-CA1 terminated today—five years after the drug’s initial conditional approval date. The FDA did not approve Kinavet-CA1 by December 15, 2015, and therefore, the drug’s conditional approval is no longer in effect as of that date.
AB Science must cease marketing Kinavet-CA1 and distributors must cease distributing the drug to veterinary clinics. Veterinarians may want to discuss other available approved treatments with dog owners. For example, the drug Palladia (toceranib phosphate, NADA 141-295), which is FDA-approved for the treatment of mast cell tumors in dogs, may be appropriate in some cases. Also, other FDA-approved animal and human drugs may potentially be used legally in an extralabel manner in dogs with mast cell tumors.
- Dear Veterinarian Letter on Kinavet-CA1
- Freedom of Information Summary for Kinavet-CA1, Application for Conditional Approval 141-308, December 15, 2010 (PDF - 437KB)
Conditional Approval Explained: A Resource for Veterinarians Minor Use/Minor Species Lions and Tigers and Bears! OMUMS! Unapproved Animal Drugs
- Freedom of Information Summary for Palladia, New Animal Drug Application (NADA) 141-295, May 22, 2009 (PDF - 530KB)
The Ins and Outs of Extra-Label Drug Use in Animals: A Resource for Veterinarians