This conditional approval is the first under the 2018 reauthorization of the FDA’s Animal Drug User Fee Act program, through which Congress granted the FDA a limited expansion of the conditional approval pathway for certain new animal drugs.
Officials with the FDA have granted conditional approval to potassium bromide chewable tablets (KBroVet-CA1; Pegasus Laboratories Inc.) for control of seizures in dogs with idiopathic epilepsy. This conditional approval is the first under the 2018 reauthorization of the FDA’s Animal Drug User Fee Act program, through which Congress granted the FDA a limited expansion of the conditional approval pathway for certain new animal drugs.
Idiopathic epilepsy is a type of seizure disorder without a known cause. Potassium bromide tablets work by stabilizing neurons in the central nervous system to reduce the likelihood of having a seizure. There is currently no other drug approved and marketed in the United States for the treatment of idiopathic epilepsy in dogs, a serious or life-threatening condition that affects approximately 5% of the canine population.
The initial conditional approval for potassium bromide chewable tablets is valid for 1 year with the potential for 4 annual renewals. During this time, the animal drug sponsor must demonstrate that it is actively working toward collecting the remaining effectiveness data needed to achieve full approval.
Conditional approval allows an animal drug sponsor to legally market its product after demonstrating that the drug is safe and manufactured in accordance with full approval standards, and that there is a reasonable expectation of effectiveness for use.
Prior to this expansion, the FDA’s conditional approval of new animal drugs had been limited to drugs for use in minor species—those other than horses, dogs, cats, cattle, pigs, turkeys, and chickens—or for diseases in the major species that occur infrequently, or in limited geographic areas, and in only a small number of animals annually. The expanded authority allows for conditional approval of treatment options that are intended to address a serious or life-threatening disease or condition, or an unmet health need, but for which demonstrating effectiveness would require complex or particularly difficult studies.
According to the FDA, potassium bromide has been used to control seizure disorders in dogs for an extensive period of time, however, prior to being granted the new authority, the agency had no animal drug sponsor apply for approval.
The most common adverse drug events associated with potassium bromide were found in the neurologic, gastrointestinal, reproductive, endocrine, dermatologic and respiratory systems. Some dogs also had increased thirst and urination. Dogs with decreased kidney function may be at greater risk for bromide intoxication.
KBroVet-CA1 is orally administered daily and is available only by prescription. According to the FDA, it is important for owners of dogs with idiopathic epilepsy to work closely with their veterinarians to monitor clinical signs in order to control potential seizures that may result from bromide intoxication. It is also important to avoid abrupt diet changes in dogs receiving potassium bromide because it could either compromise seizure control or raise safety concerns.
Signs of severe bromide intoxication can include depression, behavioral changes, ataxia, hind limb paresis, mydriasis, stupor and coma.
FDA Grants First Conditional Approval Under Expanded Authority to Control Seizures in Dogs with Idiopathic Epilepsy [news release]. Silver Spring, MD; January 14, 2021: FDA. Accessed January 18, 2021. https://www.fda.gov/news-events/press-announcements/fda-grants-first-conditional-approval-under-expanded-authority-control-seizures-dogs-idiopathic