Most of us are familiar with Herceptin® – the medicine that transformed the treatment of HER2-positive breast cancer in the early 2000s. Herceptin® is the brand name for this drug which is supplied by pharmaceutical company Roche. Trastuzumab is its generic name.
Roche’s patents on Herceptin®/trastuzumab expired in Europe in 2014 and in the United States in 2019. Now a number of copies of this medicine – called trastuzumab biosimilars – have been developed by other companies and are on the market. With several competing products available, their prices are highly likely to be lower than for the original drug.
Trastuzumab is a ‘biologic’ medicine – it is a monoclonal antibody which has to be grown in a living cell culture system, rather than a drug that can be produced by a purely chemical reaction. When a new company wants to produce a copy of a biologic medicine, it will develop its own biological system to ‘grow’ the medicine. This system could be different from the original one, and the final product will be highly similar but not identical to the original. Hence the term ‘biosimilar’.
Before it comes to market, each product is tested to ensure that it works as well and is as safe as the original. When granting approval for use in New Zealand, Medsafe uses the same evaluation procedure as the European Medicines Agency. This includes looking at the pharmacodynamics (what the drug does to the body) and pharmacokinetics (what the body does to the drug) of each biosimilar compared to the original. Data from laboratory experiments and clinical trials are evaluated. Suppliers must also submit results from immunogenicity tests – these are important for determining if it will be safe for patients already being treated to be switched to the biosimilar (‘interchangeable’ drugs).
In New Zealand, our drug-buying agency Pharmac opened a tender for a trastuzumab biosimilar in 2020. In August 2023 Pharmac approved funding for Herzuma® (supplied by Celltrion) in New Zealand.
You can read Medsafe’s consumer information leaflet on Herzuma® here.
In Australia, trastuzumab Herceptin® and its biosimilars Herzuma®, Kanjinti®, Ogivri®, Trazimera® and Ontruzant® are all subsidised by the government and available in the public system. Trastuzumab biosimilars have been approved and used in Europe, the United States and England since 2018.
28 March 2025
