Genentech Issues Warning on Herceptin

SOUTH SAN FRANCISCO—Genentech Inc. has issued a “Dear Doctor” letter to alert physicians to 62 postmarketing reports of serious adverse events related to the use of trastuzumab (Herceptin), the company’s anti-HER-2 monoclonal antibody for use in treating HER-2-positive breast cancer. To date, about 25,000 women have been treated with Herceptin worldwide.

The adverse events include hypersensitivity reactions, infusion reactions, and pulmonary events. Fifteen patients had pulmonary and other adverse events following Herceptin infusion, which led to death. Nine had onset of symptoms within 24 hours of infusion. Most of the patients with fatal events had significant preexisting pulmonary compromise secondary to intrinsic lung disease and/or malignant pulmonary involvement.

Herceptin product labeling will be modified with additions to the warnings and adverse reactions sections.