Name Confusion Could Lead to Mix-up of Two Breast Cancer Drugs

The FDA notified health care professionals that the use of incorrect generic name for Kadcyla (ado-trastuzumab emtansine; Genentech) in some medication-related electronic systems poses a risk of medication error with Herceptin (trastuzumab; Genentech). Kadcyla and Herceptin are both human epidermal growth factor receptor (HER2) inhibitors indicated for the treatment of metastatic breast cancer.

Some third-party publications, compendia references, health information systems, and internet sites have been incorrectly using Kadcyla’s United States Adopted Name (USAN) as “trastuzumab emtansine,” and omitting the “ado-” prefix. This truncated version of Kadcyla’s generic name may cause confusion with Herceptin (trastuzumab).


Due to the significant differences in dosing and treatment schedules for Kadcyla and Herceptin, a mix-up of these products could lead to dosing errors and potential harm to patients. So far, no medication errors related to confusion between Kadcyla and Herceptin have been reported to FDA since the approval of Kadcyla (Feb 2013). However, medication errors did occur during its safety and efficacy trials prior to approval.

The FDA recommends that health care professionals use both the FDA-approved brand and generic name when communicating medication orders, on preprinted order sets, and in computerized order entry systems.

For more information visit the FDA Safety Alerts website