MacroGenics Pauses Cancer Drug Trial After Safety Issues

FDA places hold on Phase 2 study of lorigerlimab due to adverse events in enrolled patients.

Published on Feb. 24, 2026

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MacroGenics, a biopharmaceutical company based in Rockville, Maryland, has paused enrollment in a Phase 2 clinical trial of its cancer drug lorigerlimab after the FDA placed a hold on the study following reports of serious safety events in four enrolled patients. The adverse events included Grade 4 thrombocytopenia, myocarditis, neutropenia, and concurrent septic shock.

Why it matters

The pause in the lorigerlimab trial is a setback for MacroGenics, as the drug was being evaluated as a potential new treatment for gynecological cancers. Safety issues in clinical trials can significantly delay or even derail the development of new drugs, which is a critical concern for biopharmaceutical companies and the patients who rely on their innovations.

The details

According to the company, 41 study participants had been dosed with lorigerlimab every three weeks prior to the trial being paused. Enrolled patients will be allowed to continue receiving the study drug, but no new patients will be added to the trial until the safety issues are resolved and the FDA lifts the clinical hold.

  • On February 23, 2026, MacroGenics notified the FDA of a pause in enrollment due to recent safety events.
  • The FDA subsequently placed a hold on the Phase 2 trial of lorigerlimab.

The players

MacroGenics

A biopharmaceutical company based in Rockville, Maryland that is developing the cancer drug lorigerlimab.

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What’s next

MacroGenics will work closely with the FDA to address the safety concerns and resolve the clinical hold on the lorigerlimab trial.

The takeaway

The pause in MacroGenics' cancer drug trial highlights the challenges and risks inherent in the drug development process, where patient safety is the top priority. This setback underscores the need for rigorous clinical testing to ensure new treatments are both effective and safe before they can be approved for widespread use.