Review: Biosimilar-to-Biosimilar Switching Is Safe, Effective

In light of the growing evidence that supports the safety of switching from a reference product to a biosimilar, a systematic review reveals that biosimilar-to-biosimilar switching may also be safe for patients.

The review, which was published in BioDrugs, compiled data from 23 observational studies, selected from 982 original findings, to answer the question of whether switching patients from a biosimilar to another contributed to adverse clinical outcomes, including reduced efficacy or compromised safety.

Patients may have to switch from a reference biologic to a biosimilar or from one biosimilar to another because of changing insurance mandates, pharmacy benefit managers interfering in formulary placements, or policy limitations intended to reduce costs. Additionally, patients may be subject to different drug coverage while they’re traveling or if they relocate to another region.

A US survey found that 70% of patients with cancer don’t know what biosimilars are. The authors noted that some patients and providers may assume that because a biosimilar is cheaper and was approved using a different clinical development paradigm compared to a reference product that a biosimilar may lead to increases in adverse events or reduced effectiveness. Another issue is that patients who are told to switch to a biosimilar may experience the nocebo effect, where a patient’s negative attitude towards a product results in adverse clinical outcomes.

“The possibility of multiple switches between biosimilars of the same reference biologic is already a reality, and these types of switches are expected to become more common in the future…. Proof that biosimilars from the same reference biologic are equivalent in terms of effectiveness and safety is required to support switching between biosimilars of the same reference biologic,” the authors wrote.

The authors conducted an electronic database search for US- or EU-based studies that involved biosimilar-to-biosimilar switching through the end of December 2021. The studies could assess biosimilars for erythropoietin, human growth hormone, filgrastim, etanercept, adalimumab, infliximab, and rituximab. The literature had to be human studies published in English.

Among the 23 real-world observational studies that were included in their analysis, 13 were published in peer-reviewed journals and 10 derived from abstracts shared at conferences. The studies were heterogenous in size, design, and endpoints. Overall, 3657 patients were involved, and no randomized control trials were identified.

The majority of the studies focused on switches between infliximab biosimilars (n = 17), followed by adalimumab biosimilars (n = 3), etanercept biosimilar (n = 2), and rituximab biosimilars (n = 1).

The authors concluded that although the number of available studies was small, their review demonstrated that biosimilar-to-biosimilar switching did not compromise patients’ safety or clinical outcomes. They also stressed that physicians, nurses, and clinical pharmacists could play a critical role in educating patients on the safety, efficacy, and benefits of biosimilars as well as influencing biosimilar adoption.

The authors mentioned several limitations of the review, including the observational nature of the studies and the inclusion of potentially non-peer-reviewed abstracts that may only contain preliminary or interim data. It was noted that as more switches occur in the future, more data on biosimilar-to-biosimilar switched will emerge.

“Given that it is a current topic of interest to HCPs, their patients, and healthcare systems, it is useful to collate and evaluate existing data even while acknowledging that additional data will likely become available in the future,” they wrote.

Reference

Cohen HP, Hachaichi S, Bodenmueller W, Kvien TK, Danese S, Blauvelt A. Switching from one biosimilar to another biosimilar of the same reference biologic: a systematic review of studies. BioDrugs. Published online July 6, 2022. doi:10.1007/s40259-022-00546-6