Analyzing Experiences in Non-Medical Switching to Trastuzumab Biosimilars Among Oncologists and Patients With Breast Cancer

When patients with breast cancer are required to switch from trastuzumab to a trastuzumab biosimilar for non-medical reasons, patients are often concerned about biosimilar effectiveness, safety, and side effects, as are most oncologists in community or private practice. Moreover, knowledge among oncologists about basic features of biosimilars is low. To understand the experiences of patients and oncologists during a switch from trastuzumab to a trastuzumab biosimilar, US researchers developed 2 internet surveys, used social media to recruit respondents, and administered the surveys via REDCap in 2020-2021 (Br Ca Res Treat. 2022; doi:10.1007/s10549-022-06615-2). 

Respondents included 143 patients with breast cancer and 33 medical oncologists. Most of the patients (64%) switched to a trastuzumab biosimilar, and two in five (41%) had no advance notice of the switch. 

“Lack of notification equates to lack of choice and opportunity to engage, as well as the absence of shared decision-making (or the perception of [such]) between the patient and their care team,” wrote Elizabeth Papautsky, PhD, Department of Biomedical and Health Information Sciences, University of Illinois, Chicago, IL, and colleagues.

None of the oncologists reported that they had initiated the switch, and many reported the switch was initiated by the insurer (45%). “Some oncologists reported that this switch was done without their knowledge,” noted Dr Papautsky and team.

Responses from patients indicated that many learned about biosimilars on their own (44%), and many wanted more time to discuss the biosimilar with their oncologist (41%). About 55% had not received material about the biosimilar from the pharmaceutical manufacturer.

These findings prompted Dr Papautsky and team to conclude that, “There is a need for tailored and effective patient and oncologist information and education on trastuzumab biosimilars, along with improved healthcare communication regarding switching.” 

The researchers also found a divergence between the responses of patients and oncologists to several survey items. The greatest differences in responses occurred regarding agreement with the following statements, which was substantially greater for oncologists than for patients: “The cancer is/will be treated as effectively with biosimilar trastuzumab,” (79% vs. 43%), “The patient had the opportunity to ask questions about a switch to biosimilar trastuzumab,” (59% vs. 35%), and “Switching to a biosimilar trastuzumab is a minor change in the patient’s care,” (67% vs. 37%).

“The discrepancy between patient-reported experiences and oncologist perceptions of the patient experience suggests a lack of adequate information that may be a challenge not only to the uptake of trastuzumab biosimilars but to the patient-oncologist relationship,” Dr Papautsky and colleagues commented.

Patients and oncologists had similar negative responses to items covering patient involvement, patient emotional adjustment, and degree of trust in the hospital. Regarding trust, the authors concluded that “Our work identifies an opportunity for better system support for both oncologists and patients.” Regarding patient involvement and adjustment, “the oncologist responses provide insight into appreciation that patients are impacted by the communication (or lack thereof) that underlies decision-making processes.”

“Ultimately, effective communication about trastuzumab biosimilars is not the sole responsibility of individual oncologists, but rather an objective in need of systems-level interventions,” Dr Papautsky and colleagues concluded.