ONTRUZANT is a biosimilar to the original biologic medication, Herceptin (trastuzumab), which is widely used in the treatment of certain types of breast cancer and gastric cancer. ONTRUZANT is designed to target and inhibit the function of the HER2 protein, which is overexpressed in some cancer cells, leading to their growth and proliferation. By binding to the HER2 protein, ONTRUZANT helps to stop the growth of these cancer cells and can be used as part of a combination therapy to treat HER2-positive breast and gastric cancers. As a biosimilar, ONTRUZANT has been rigorously tested to ensure it is highly similar to Herceptin, with no clinically meaningful differences in terms of safety, purity, and potency, offering a more cost-effective option for patients requiring treatment with trastuzumab.