OBJECTIVES: With the patent expiration of the reference product trastuzumab in Europe in 2014, several companies are developing biosimilar versions of trastuzumab. In the near future, these lower priced products can contribute to significant cost savings in the heavily burdened healthcare budgets. The market access and uptake of these biosimilars will predominately depend on price and the clinical evidence submitted for registration. The number of authorized biosimilars in turn may affect the level of competition, the magnitude of savings and the number of patients treated. Therefore, this study aims to provide an overview of the clinical trial evidence for biosimilars to trastuzumab in an advanced stage of development.

METHODS: A literature review was carried out in a systematic way using databases Embase and Medline between February and June 2017. Additionally, the ClinicalTrials.gov website, abstracts, conference posters and press releases were consulted.

RESULTS: In June 2017, at least seven potential trastuzumab biosimilars have completed phase I clinical trials. Six of these subsequently completed phase III trials and four dossiers were submitted for approval to EMA. The reported phase I and phase III clinical trial data are indicative for biosimilarity of the proposed biosimilars to the reference product. Of note is the considerable variation in the phase III clinical development programs of these biosimilars in terms of selected endpoints, patient population (disease stage) and trial design.

CONCLUSIONS: Several trastuzumab biosimilars are expected to enter the market in the following months. Their introduction will drive significant cost savings as well as improve patient access to essential treatment. A first-to-market advantage has been demonstrated for biosimilars in the past, potentially resulting in a higher uptake of the first trastuzumab biosimilar entering the market. The identified variation in the clinical development of the different trastuzumab biosimilars may influence healthcare professionals’ decision-making and may therefore impact their uptake.