The Food and Drug Administration canceled a temporary approval for a drug used to treat mast cell tumors in dogs.
Sales of Kinavet-CA1 (masitinib mesylate) became illegal Dec. 15, 2015, when AB Science’s conditional approval for the drug expired.
The agency grants such approvals for drugs intended for use in minor species, such as ferrets, or minor uses, such as treatment of certain types of cancers in dogs, if the owners of the drugs prove the drugs are safe and can be used with reasonable expectation of effectiveness. But companies have five years to prove their drugs are effective enough to meet FDA standards for full approval, before conditional approval expires.
Kinavet-CA1 had gained conditional approval Dec. 15, 2010.
In announcing the approval expiration, agency officials noted that the drug Palladia (toceranib phosphate) also is approved for treating mast cell tumors in dogs and may be appropriate in some of the same cases.
“Also, other FDA-approved animal and human drugs may potentially be used legally in an extralabel manner in dogs with mast cell tumors,” the announcement states.