The U.S. Food and Drug Administration issued draft guidance proposing conditions under which biopharma developers could reduce or waive nonclinical primate testing for certain monoclonal antibodies. The agency framed the guidance as a science‑based pathway to use alternative in vitro assays and platform‑knowledge approaches where appropriate, with the stated goals of accelerating development and reducing animal use. FDA documents and press coverage emphasize that the recommendations apply selectively—based on mechanism, binding species conservation and existing platform data—and that sponsors must provide justification. The move aligns with broader regulatory trends toward reliance on mechanistic, human‑relevant data and platform experience to limit nonhuman primate studies when scientifically supported. Industry stakeholders welcomed clarity but flagged implementation challenges, including harmonization with overseas regulators and the need for clear acceptance criteria for alternative assays.