Biosimilar trastuzumab cuts an expensive obstacle to effective treatment for many women with HER2+ breast cancer

Article title: Clinical development of CT-P6 in HER2 positive breast cancer

Citation: Fu C et al. Expert Opin Biol Ther 2019:19(10);987-992

Publication date: September 2019

The extensive preclinical and clinical testing program for CT-P6 demonstrates this biosimilar is as safe and effective as reference trastuzumab, and its clinical use could considerably reduce financial toxicity without compromising care.

The development of trastuzumab monoclonal antibody in the 1990s was a milestone in targeted therapy that has dramatically improved progression-free and overall survival rate in patients with breast cancer overexpressing the HER2 receptor (which account for 15% of all breast cancer diagnoses).

The success of trastuzumab opened the floodgates for a new generation of targeted therapies for both early-stage and metastatic breast cancer and other solid tumours – although at a huge financial burden. Biosimilars were developed in response to this problem. CT-P6 (trastuzumab-pkrb, Herzuma) is a trastuzumab biosimilar currently approved in the EU, Japan, South Korea, Australia, and USA. Like all biosimilars, CT-P6 underwent rigorous testing during pre-approval stage. In head-to-head comparisons CT-P6 demonstrated equivalent pharmacokinetics parameters, adverse events profile, immunogenicity level and anti-cancer efficacy compared with reference trastuzumab. Clinical trials have been conducted in women with stage I–IIIa operable HER2-positive breast cancer. These trials revealed that neoadjuvant CT-P6 added to chemotherapy does not elicit a significantly different pathologic complete response rate to the same treatment approach using the reference, trastuzumab.

In all, the totality of evidence for CT-P6 supports its biosimilarity to the reference, trastuzumab. CT-P6 can be safely used in patients with HER2-positive breast cancer and other malignancies where indicated. Rapid integration of economically favourable biosimilars such as CT-P6 promises to improve access to essential medicines and help alleviate overburdened healthcare systems.

Key takeaway

The development of the trastuzumab biologic dramatically improved outcomes for a large proportion of HER2-overexpression breast-cancer patients, although the financial burden has been high. The trastuzumab biosimilar, CT-P6, shows comparable pharmacokinetic parameters and anti-cancer efficacy compared to the reference biologic, and with lower associated costs, makes it economically favourable to healthcare providers.