The FDA guidance document “Oncology Pharmaceuticals: Reproductive Toxicity Testing and Labeling Recommendations” was finalized in May 2019 and provides information for the development of pharmaceuticals that are intended to treat patients with cancer. The guidance notes that, in some cases, a weight-of-evidence approach showing potential for reproductive toxicity may eliminate the need to conduct a dedicated embryofetal development study. Such weight-of-evidence approaches can consider data from alternative assays, such as fit-for-purpose in vitro, ex vivo, or nonmammalian in vivo assays. The guidance also illustrates other cases where certain developmental and reproductive toxicity testing may not be warranted.