Immunological Techniques

Herceptin (trastuzumab) is a monoclonal antibody used specifically to treat HER2-positive breast cancer. It binds to the HER2 receptor, inhibiting the growth of cancer cells.

• Option A: Correct. Approved for treatment of early stage and metastatic HER2-positive breast cancer.
• Option B: Incorrect. This relates to immunosuppressive therapies.
• Option C: Incorrect. Erythropoiesis stimulators are different biologics.
• Option D: Incorrect. Not related to heart attack treatment.

Thus, the correct answer is (A) Therapy of early stage breast cancer.