The safety of CANALEVIA-CA1 and crofelemer was evaluated in four laboratory studies.
Target Animal Safety Study: In a 9 day laboratory safety study, healthy four month old Beagle dogs were orally administered crofelemer at 0, 27.2, 54.3, or 162.9 mg/kg twice daily (4 dogs per sex in each group) for 9 days. All dogs survived to study termination.
Clinical observations related to CANALEVIA-CA1 included discolored red feces, watery feces, and vomiting in a dose-dependent manner with increased incidence in the higher dose groups.
Hematology findings related to CANALEVIA-CA1 included 3 dogs that had a decreased hematocrit (reference range 37.2-52%) at study end compared to acclimation: 1 male administered 27.2 mg/kg with hematocrit of 39.6% prior to dosing and 35.8% on Day 9; 1 female administered 162.9 mg/kg with hematocrit of 40.7% prior to dosing and 36.4% on Day 9; and 1 female administered 162.9 mg/kg with hematocrit of 36.4% prior to dosing and 36.1% on Day 9.
There were no clinically relevant or significant findings for body weight, physical examination, food consumption, electrocardiogram, ophthalmoscopic, or necropsy examinations.
Target Animal Toxicity Studies: In two separate laboratory studies, healthy six to seven month old Beagle dogs were orally administered crofelemer (not commercial formulation) at 0, 50, 175, or 600 mg/kg once daily (four dogs per sex in each group) for 30 days and nine months duration, respectively. All dogs survived to study termination.
Clinical observations related to crofelemer included abnormal feces (mainly black and rust colored mucoid feces and diarrhea) observed as soon as 1 day after the first administration and occurred in a dosedependent manner with increased incidence in the higher dose groups. Dogs in the 600 mg/kg/day group did not gain weight at the same rate, had decreased food consumption, and higher incidences of vomiting compared to the other groups.
Hematology findings related to crofelemer at the dose of 600 mg/kg/day were consistent with a microcytic, hypochromic anemia with mild regeneration, and thrombocytosis as characterized by decreases in hemoglobin, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration; and increases in platelets, percent reticulocytes, and absolute reticulocytes compared to the other groups. Females at 175 mg/kg/day and males and females at 600 mg/kg/day had increased neutrophils compared to the other groups. Crofelemer-related serum chemistry findings at 600 mg/kg/day, and to a lesser severity at 175 mg/kg/day, included decreased albumin, total protein, cholesterol, calcium, and sodium and increased potassium compared to the other groups.
On necropsy, gross lesions related to crofelemer included localized irritation of the gastrointestinal tract (reddened areas, erosion, and red streaks) and discoloration of the gastrointestinal tract (dark red areas and gray areas) and lymph nodes (red, gray, and green). Gross lesions were observed at all crofelemer doses in a dose-dependent manner where higher doses had higher incidences.
On histopathology, crofelemer-related lesions included congestion in the small and large intestines; inflammation and pigmentation of the gastrointestinal tract and pigmentation in the liver; congestion in the mesenteric and suprapharyngeal lymph nodes; histiocytosis, erythrocytosis, basophilic bodies, and pigmentation of the lymph nodes; and splenic macrophage infiltration. Histopathologic lesions occurred in a dose-dependent manner where the higher doses had higher incidences.
Cardiovascular Study: The cardiovascular effects of crofelemer (not commercial formulation) were evaluated in a laboratory study in four healthy one to one and a half years old male Beagle dogs implanted with radiotelemetry devices. Dogs were orally administered crofelemer at 0, 60, 200, and 600 mg/kg one time. Each dog received all treatments with a seven day washout period between treatments. There were no crofelemer-related effects on the cardiovascular parameters (heart rate, blood pressure, electrocardiograms). Clinical observations related to crofelemer included soft, watery, mucoid, or discolored (brown or red) feces in the 200 and 600 mg/kg groups.