SB3 (Ontruzant): A Trastuzumab Biosimilar.

SB3 (Ontruzant) is the first biosimilar of the reference anti-HER2 antibody trastuzumab to be approved in the EU. It is approved for use in all indications for which reference trastuzumab is approved, namely HER2-positive early breast cancer, metastatic breast cancer and metastatic gastric cancer. SB3 has similar physicochemical and pharmacodynamic properties to those of reference trastuzumab, and the pharmacokinetic biosimilarity of the agents has been shown in healthy volunteers and women with HER2-positive early or locally advanced breast cancer. SB3 demonstrated clinical efficacy considered equivalent to that of reference trastuzumab in women with HER2-positive early or locally advanced breast cancer. The tolerability, immunogenicity and safety profiles of SB3 were similar to those of reference trastuzumab. The role of reference trastuzumab in the management of HER2-positive cancers is well established and SB3 provides an effective biosimilar alternative for patients requiring trastuzumab therapy.