Excreta contamination after antibody-drug conjugates administration: a systematic review and guidance for hospital pharmacists.

Antibody-drug conjugates (ADCs) are increasingly used in oncology practice, yet guidance is lacking regarding the safe handling of patient excreta after administration. As ADCs contain cytotoxic payloads and active metabolites that may be excreted via urine or faeces, evidence-based recommendations are required to support hospital pharmacists in the development of guidelines for the safe handling of excreta from patients treated with these hazardous drugs. Therefore, this review aimed to evaluate the available evidence on ADC excretion and to develop practical recommendations for precautionary handling periods. A systematic literature search of three databases (PubMed, Scopus, and Embase) was performed to identify human and preclinical studies reporting excretion or mass balance data for approved ADCs. Two pharmacists independently screened studies and extracted relevant data. Evidence was summarised descriptively. Practical precautionary periods were developed by consensus among the authors. For ADCs without published mass balance data, conservative estimates were calculated using seven terminal half-lives reported in the Summary of Product Characteristics. Of 328 unique records identified, six studies met the inclusion criteria and included data on five ADCs. Available evidence demonstrated predominantly biliary/faecal excretion of cytotoxic payload-related compounds, with limited urinary elimination. In most studies, more than 80% of the administered dose was recovered within 14 days. Based on available evidence and pharmacokinetic estimates, recommended precautionary handling periods for patient excreta ranged from 5 to 144 days across currently authorised ADCs. This review provides a practical overview of available ADC excretion data relevant for hospital pharmacists and healthcare professionals in oncology. The proposed precautionary periods may support hospital pharmacists in the development of local handling procedures and contribute to safer management of patient excreta by nurses and other healthcare professionals involved in oncology care.