Animal & Veterinary
Conditional Approval of Animal Drugs - What Does This Mean for Veterinarians?
by Laura Alvey, Center for Veterinary Medicine, FDA Printer-friendly PDF 
With the recent and first conditionally-approved animal drug for a major species under the Minor Use and Minor Species (MUMS) Animal Health Act, Kinavet-CA1 (masitinib mesylate), it may be helpful for veterinarians to understand the differences between conditionally-approved animal drug products and fully-approved products. Kinavet-CA1 was conditionally-approved for the treatment of recurrent (post-surgery) or nonresectable Grade II or III cutaneous mast cell tumors in dogs that have not previously received radiotherapy and/or chemotherapy except corticosteroids.
A conditional approval allows a sponsor to market a drug before they have collected all the necessary effectiveness data, as long as the sponsor has demonstrated that there is a reasonable expectation that the drug is effective. The sponsor also has to prove the drug is safe in accordance with the full FDA approval standard prior to receiving conditional approval. In fact, the product labeling includes a specific statement required by the MUMS Act: "Conditionally approved by FDA pending a full demonstration of effectiveness under application number XXX-XXX." The sponsor may market a conditionally-approved drug for up to five years, subject to annual renewals, while collecting substantial evidence of effectiveness. A fully-approved drug has already demonstrated substantial evidence of effectiveness and safety prior to marketing; therefore, there are no limitations on marketing.
Because full effectiveness of Kinavet-CA1 has yet to be demonstrated and only a reasonable expectation of effectiveness has been demonstrated for the specific indication, use of the drug in an extra-label manner is not allowed. It’s critical that veterinarians only use the drug for its approved indication. In order to drive this point home, the labeling under the CAUTION heading explicitly states, “Federal (USA) law restricts this drug to use by or on the order of a licensed veterinarian. Use only as directed. It is a violation of Federal Law to use this product other than as directed in the labeling.” Under certain conditions, a fully approved drug may be used in an extra-label manner.
In addition, there is a "CA1" after the product’s name (Kinavet) which indicates that the drug is conditionally approved (CA) and that this is the first (1) conditionally-approved application for this drug product.
