title: Lack of respiratory and contact sensitizing potential of the intranasal antiviral drug candidate rupintrivir (AG7088): a weight-of-the-evidence evaluation.
abstract: Rupintrivir, also known as AG7088, is a small molecule 3C protease inhibitor designed to target human rhinovirus as a potential intranasal treatment for the common cold. The ability of rupintrivir to induce both respiratory and contact hypersensitivity responses was evaluated using a weight of the evidence approach. A local lymph node assay (LLNA) in mice evaluating concentrations of rupintrivir up to 50% in dimethylformamide showed no evidence of sensitizing capability. An irritation study conducted in rabbits was performed to assess potential dermal irritancy and provide information for worker safety guidelines. The study showed no evidence of skin irritation when the material was placed in direct contact with the skin in a semi-occluded fashion for four days. Quantitative whole body autoradiography (QWBA) following intranasal instillation of the compound into rabbits showed that the compound was retained in the nasal cavity or was swallowed. No radioactivity was observed in the pulmonary regions of these animals. Histopathologic evaluation of the nasopharyngeal tract and the lungs of both rats and dogs exposed by intranasal instillation acutely or following repeated intranasal exposures for 14 (rat) or 28 days (rat and dog) did not reveal any evidence of irritation or inflammation in these regions of the respiratory tract. These data demonstrate that rupintrivir does not cause irritation or inflammatory responses that may precede the development of sensitization of the skin or respiratory tract. It was concluded that the weight of the available toxicologic evidence indicated that rupintrivir was not likely to cause sensitization of either the skin or the respiratory tract in humans following intranasal delivery.
authors.affiliation: Worldwide Safety Sciences, Pfizer Global Research and Development, San Diego, CA 92064, USA. leighann.burns@pfizer.com
authors.forename: Leigh Ann
authors.initials: LA
authors.lastname: Burns-Naas
authors.forename: Caroline
authors.initials: C
authors.lastname: Lee
authors.forename: Winston
authors.initials: W
authors.lastname: Evering
authors.forename: Lisa
authors.initials: L
authors.lastname: Ahern
authors.forename: Stephanie
authors.initials: S
authors.lastname: Webber
authors.forename: Mark
authors.initials: M
authors.lastname: Zorbas