Evaluation of the Developmental Toxicity of Vedolizumab, an α(4)β(7) Receptor Antagonist, in Rabbit and Nonhuman Primate

Vedolizumab, a humanized monoclonal antibody approved for the treatment of adults with moderately to severely active ulcerative colitis or Crohn disease, targets α(4)β(7) integrin and selectively blocks gut-specific lymphocyte trafficking. The potential effects of vedolizumab on development were assessed by standard preclinical toxicity studies in rabbits and cynomolgus monkeys. A single infusion of vedolizumab (0, 10, 30, or 100 mg/kg) was administered intravenously to pregnant rabbits on gestational day 7; rabbits were monitored to gestational day 29. Vedolizumab (0, 10, or 100 mg/kg) was administered intravenously every 2 weeks to pregnant cynomolgus monkeys beginning on gestational day 20 with the last dose on gestational day 132 (9 doses total). In rabbits, vedolizumab did not affect maternal net body weight or net gains, gravid uterine weights, or mean maternal food consumption, nor did it affect intrauterine growth or fetal survival. There were also no vedolizumab effects on embryo–fetal development compared to controls. In cynomolgus monkeys, there was no increase in prenatal loss/death or stillbirth and no maternal toxicity associated with vedolizumab. On day 28 postpartum, low levels of vedolizumab were detected in the breast milk of 3 of 11 monkeys in the 100 mg/kg group. No vedolizumab-related effects on the number of infants born, infant development, or animal hematology or clinical chemistry were noted. Administration of vedolizumab to pregnant rabbits and cynomolgus monkeys did not show any potential for maternal or developmental effects.