Perjeta 420 mg Injection (Pertuzumab) is a prescription oncology medicine used in the treatment of HER2‑positive breast cancer. Pernjeta works by targeting and blocking the HER2 protein on cancer cells, helping to slow their growth and improve response to treatment. It is commonly used in combination with trastuzumab and chemotherapy agents like docetaxel for metastatic or high‑risk early breast cancer. Perjeta is administered as an intravenous infusion by trained oncology professionals, with ongoing monitoring of heart function and other labs to ensure safety. Available in Pakistan through specialist pharmacies, pricing varies depending on supplier and stock. A valid doctor’s prescription is required to purchase and use this medicine