Safety Evaluation of Initial CT-P6 Administration for 30 min during the Switch from Reference Trastuzumab in Maintenance Infusion: A Multicenter Observational Study

Adverse event reporting of marketed biosimilar and biological monoclonal antibody cancer treatments in the United States

BACKGROUND

By 8 September 2022, 10 biological monoclonal antibody (mAb) biosimilar products for cancer treatment had been approved and marketed in the United States (US). This study examined adverse event (AE) reporting patterns and disproportionate reporting signals for mAb biosimilars in the US compared to their originator biologics.

RESEARCH DESIGN AND METHODS

The US Food and Drug Adverse Event Reporting System database was used to identify AE reports for biological rituximab, bevacizumab, trastuzumab, and their marketed biosimilars. Proportions of patient age, sex and type of reporters of AEs were described for these reports. Reporting odds ratios (RORs) with 95% confidence intervals were calculated to compare reporting disproportionality in serious, death, and specific AEs between mAb biologics/biosimilars (index) and all other drugs. Breslow-Day statistic was used to determine homogeneity in RORs between each mAb biologic-biosimilar pair at p < 0.05.

RESULTS

We observed no risk signals of serious or death AE reporting for all three mAb biosimilars. A signal of disproportionate reporting of death was detected between biological and biosimilar bevacizumab (p < 0.05).

CONCLUSIONS

Our findings support the similarity in signals of disproportionate AE reporting between mAb originator biologics and biosimilars, except for death between biological and biosimilar bevacizumab.

Systematic Review on the Use of Biosimilars of Trastuzumab in HER2+ Breast Cancer

Trastuzumab is a monoclonal antibody used in the treatment of breast cancer in cases where the tumor overexpresses the HER2 receptor, a cell membrane receptor activated by the epidermal growth factor. Intravenous and subcutaneous administration of trastuzumab have comparable clinical and pharmacological characteristics, but trastuzumab biosimilars are currently only available in intravenous form. Trastuzumab biosimilars are ultimately preferred by a proportion of patients, especially in cases where co-administration of other chemotherapeutic agents, such as trastuzumab and tucatinib, a small molecule of tyrosine kinase inhibitor, is required in patients with HER-positive metastatic breast cancer. Oncologists should be well-aware of the advantages of intravenously administered trastuzumab biosimilars over subcutaneous administration, certainly also taking into account the patient’s preferences. Further cost-effectiveness analyses will be very important, along with expectations regarding successful concomitant subcutaneous administration of trastuzumab with other anticancer drugs, such as pertuzumab. This systematic review describes and analyzes the so-far published studies concerning the use of the available trastuzumab biosimilars in HER-positive early and metastatic breast cancer in terms of efficacy, safety, and cost–benefit ratio. An attempt was also made to draw some conclusions and to comment on future needs and perspectives.