Submission to APVMA on Atinvicitinib

Atinvicitinib is a highly selective drug that is metabolised in dogs to multiple metabolites, primarily cleared via hepatic metabolism with faecal excretion as the main route.

We have recommended to APVMA:

1. Require mandatory post-market pharmacovigilance with reporting intervals of 6 and 12 months, and annual reporting thereafter, with specific monitoring for neoplasia, serious infections, and haematological abnormalities.
2.  Require submission of long-term safety data from ongoing or planned studies exceeding 28 days to support chronic use claims.
3. Request Phase II environmental data (aquatic ecotoxicity on algae, Daphnia, fish; environmental fate) as a post-approval commitment, consistent with Australia's unique ecological sensitivity and alignment with Australia's commitment to protecting waterways and biodiversity. While the EMA Phase I trigger was not met, Australia's environmental context (proximity of urban waterways to sensitive ecosystems, unique aquatic biodiversity) may warrant additional caution.
4. Ensure labelling includes: clear warnings about immunosuppression and infection risk; recommendation for veterinary monitoring including regular blood work; notification of synthetic chemical presence in the product which may be relevant where animals reside on certified organic, biodiversity, or biosecurity-sensitive properties or areas; environmental disposal instructions consistent with best practice; and precautionary language for handlers (gloves, hand hygiene).
5. Approval should be conditional on the understanding that atinvicitinib does not replace, but supplements, the existing therapeutic options. Label language should encourage multimodal management of canine atopic dermatitis and veterinary oversight.
6. That the APVMA request, as a post-approval information requirement, basic environmental fate data (soil persistence, biodegradation) for atinvicitinib and its primary faecal metabolites. This data would serve a dual purpose: supporting the environmental safety conclusion and enabling organic certifying bodies to make informed decisions about companion animal pharmaceutical use on certified properties. This is consistent with the APVMA's statutory obligation to consider whether the proposed use of a product may have unintended effects that are harmful to animals, plants, things, or the environment (Agricultural and Veterinary Chemicals Code Act 1994, s. 5A).

Read the full submission: Submission to APVMA on Atinvicitinib