The European Commission approved Pfizer’s first oncology biosimilar Trazimera, a drug modeled after Herceptin that is intended to treat certain breast, gastric and esophageal cancers.

The drug is intended for treating HER2 overexpressing breast cancer and HER2 overexpressing metastatic gastric or gastroesophageal junction adenocarcinoma.

The drug’s active substance, trastuzumab, a monoclonal antibody, binds to the HER2 protein and inhibits the production of tumor cells.