Keytruda (pembrolizumab) is an immune checkpoint inhibitor used to treat multiple cancers. While effective, it causes immune-related adverse events (irAEs) including severe colitis, hepatitis, pneumonitis, and endocrine organ failure in a subset of patients. Claims allege Merck failed to adequately warn about the severity and irreversibility of some irAEs and promoted Keytruda for off-label uses with greater toxicity risk.
PD-1 inhibition releases immune brakes system-wide, causing autoimmune attacks on normal tissue. Severe irAEs (Grade 3-4) can be permanent. Claims focus on whether Merck adequately warned oncologists and patients about irreversible irAE risk, particularly for off-label combinations and extended duration use.
Pembrolizumab (Keytruda) immune-related adverse event cases allege Merck failed to adequately warn of severe autoimmune organ damage. Cases involve pneumonitis, colitis, hepatitis, and other immune-mediated injuries. No MDL formed yet.