Strategies to reduce the use of non-human primates in development of oncology ADCs with cytotoxic payloads

The use of non-human primates (NHP) for the nonclinical development of biologics can be necessary to assess the potential safety risks in humans. An IQ DruSafe and 3Rs TPS Working Group (WG) conducted a survey on the use of NHP in toxicology studies used to develop antibody drug conjugates (ADCs) with cytotoxic payloads for oncology treatment. The survey addressed whether a Good Laboratory Practice (GLP) 3-month NHP study provides additional safety information relative to the 1-month GLP NHP or relative to the 3-month GLP rodent study. Questions from the survey included whether a 3-month NHP study was conducted and if so, were the results similar or not to the 3-month rodent study or the 1-month NHP study, if the toxicities observed were consistent with the expected toxicities of the ADC payload, and whether the toxicities translated to that observed in the clinic. In addition, survey questions addressed study design elements particularly related to the number of animals used in studies. Survey results indicated that target organ toxicities were generally similar between studies, were translatable to humans, and most were attributed to the payload. Overall, the survey results support opportunities to reduce NHP use in the development of ADCs with cytotoxic payloads in oncology.