December 21, 2021: ‘The U.S. FDA conditionally approved Canalevia-CA1 (crofelemer delayed-release tablets) for the treatment of chemotherapy-induced diarrhea in dogs.
This is the first treatment to be approved for this condition.
“Diarrhea is a common side effect of chemotherapy in dogs, which can be so severe that cancer treatment must be halted.
Chemotherapy drugs often have potential side effects, but, unlike in human medicine where patients may be willing to tolerate some discomfort in exchange for a potential cure, the primary purpose of cancer treatment in dogs and other pets is to extend survival without sacrificing quality of life and comfort,” said Steven M. Solomon, D.V.M., M.P.H., director of the FDA’s Center for Veterinary Medicine.
“This new medication provides veterinarians and dog owners with another tool to help control the side effects of chemotherapy for dogs undergoing such treatment.”
Canalevia-CA1 is available only by prescription due to the professional veterinary expertise required to properly diagnosis the cause of diarrhea and monitor dogs receiving chemotherapy.
Canalevia-CA1 is a tablet that is given by mouth and can be prescribed for home treatment.
The active ingredient in Canalevia-CA1 is crofelemer, which is approved for use in humans to treat non-infectious diarrhea in adults with HIV/AIDS who take anti-retroviral therapy.
In humans, crofelemer functions by inhibiting the secretion of chloride ions and water by intestinal epithelial cells, thereby normalizing the gastrointestinal tract. It is thought that the drug functions similarly in dogs.
Canalevia-CA1 received conditional approval through the Minor Use/Minor Species pathway, which is an option for drugs intended for minor uses in major species (dogs, cats, horses, cattle, pigs, turkeys and chickens) or for minor species.
Canalevia-CA1 qualified for conditional approval because the FDA estimates that only about 1% of dogs in the U.S. receive a diagnosis of malignant neoplasia (cancer) per year, and not all dogs that receive treatment suffer from chemotherapy-induced diarrhea.
Therefore, the agency estimates the rate of occurrence of chemotherapy-induced diarrhea in dogs in the U.S. to be fewer than 70,000 dogs, which qualifies it as a minor use in a major species.
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 the drug’s effectiveness.
The initial conditional approval is valid for one year with the potential for four annual renewals.
During this time, the animal drug sponsor must demonstrate active progress toward proving substantial evidence of effectiveness for full approval.
The animal drug sponsor has five years to obtain full approval after receiving conditional approval, or it will no longer be allowed to be marketed.
The reasonable expectation of effectiveness of Canalevia-CA1 was established in a study with 24 dogs (12 treated and 12 control). A dog was considered a treatment success if its diarrhea resolved and didn’t recur during the three-day study.
Resolution of diarrhea was defined as a fecal score of one (well-formed stool) or two (soft or very soft, moist stool that doesn’t have a clear shape).
On the third day, 9 out of 12 dogs (75%) in the treated group were treatment successes compared to 3 out of 12 dogs (25%) in the control group.
Additionally, diarrhea had resolved by 48 hours in 4 of the 12 dogs (33%) in the treated group compared to none of the dogs in the control group.
The most common side effects across the laboratory studies and field studies were abnormal feces (soft, watery, mucoid, discolored feces), decreased appetite and activity and vomiting.
Veterinarians should advise owners about the possible side effects before using the drug.
The FDA encourages dog owners to work with their veterinary team to report any adverse events or side effects potentially related to the use of any drug, including Canalevia-CA1.
The FDA granted conditional approval of Canalevia-CA1 to Jaguar Animal Health. “
