Regulators ordered a pause in patient enrollment in MacroGenics’ Phase 2 oncology trial after a patient death and multiple life‑threatening adverse events were reported. The FDA placed a partial clinical hold and instructed the company to provide further safety data and risk‑mitigation plans before resuming enrollment. MacroGenics disclosed the events to investors and halted new patient accrual while investigators and independent reviewers analyze the case and the trial’s safety profile. The company will need to satisfy FDA safety queries and may be required to amend protocols, monitoring, or eligibility criteria to resume the study. The action underscores the agency’s low tolerance for severe, unexplained toxicity in early‑to‑mid‑stage immune oncology trials and will likely affect timelines, partner negotiations, and investor sentiment for programs with similar mechanisms.