Regulators ordered a pause on enrollment in MacroGenics’ Phase 2 study of lorigerlimab following a patient death and multiple life‑threatening adverse events, prompting the company to report a partial clinical hold. The FDA’s action reflects immediate safety concerns tied to the investigational agent and will constrain MacroGenics’ ability to collect additional data while the agency reviews the events. MacroGenics disclosed the death and hold publicly as it works with regulators to define next steps. Sponsors facing abrupt safety signals typically must submit comprehensive safety datasets and protocol amendments before enrollment resumes or trials restart in a modified form.