Considerations regarding the use of nonhuman primates in assessing safety endpoints for pharmaceuticals.

Nonhuman primates (NHP) have become a commonly used nonrodent species for general toxicity testing for pharmaceuticals reviewed by CDER. Their increased use in pharmaceutical testing appears to have been driven by both increased use in small molecule drug development programs as well as a trend for biologics making up a greater percentage of pharmaceutical development programs. While always in limited supply, the COVID-19 pandemic acutely impaired the availability of NHPs for pharmaceutical testing due to disruptions in the supply and an increased demand to support COVID-19-directed research programs. Because this disruption in the NHP supply had the potential to significantly delay the development of new medications for the treatment of diseases currently without effective treatment options, FDA issued guidance in February of 2022, under its COVID-19 Public Health Emergency authority, that was intended to help mitigate the NHP supply issue by reducing the demand for NHPs. This guidance has been withdrawn with the expiration of the public health emergency. Here we discuss what impact we expect that the withdrawal of this guidance will have on efforts to minimize NHP use.