Patient Experiences, Oncologist Perceptions Differ for Trastuzumab Biosimilar Switch

In addition to needing more information and education on trastuzumab biosimilars, patients and oncologists need improved communication regarding switching, according to the results of a set of surveys.

Among patients who switched to a trastuzumab biosimilar, 40% reported not receiving any prior notification ahead of the switch, according to a study published in Breast Cancer Research and Treatment.

Due to the cost of biologics, the decision for nonmedical switching from the originator to a biosimilar may be led by insurers or health care systems, the authors noted. “With guidelines often being vague, the practice of switching is largely unregulated,” they wrote. “There is a critical need to account for the patient experience in switching to biosimilars.”

They sought to characterize the experiences of patients and oncologists during a switch from reference trastuzumab to a biosimilar when it was proposed or required by the cancer center or insurer. The researchers created 2 surveys: one survey had 60 items and was designed for patients with HER2-positive breast cancer and the other survey had 51 items and was designed for medical oncologists.

A total of 218 patients and 46 oncologists finished the survey. The oncologists had been providing treatment for a median of 10 years (range = 0-35). Among both groups, 91.4% were White. The average age was 49.59 years for patients and 46.16 years for oncologists. Slightly less than half (44.1%) of patients reported being treated at a community oncology setting. More than half (56.3%) had a diagnosis of metastatic breast cancer and 84.8% had received trastuzumab in the past year.

The analysis of the surveys found:

• 55.2% of patients said they were presented with the option to switch to a biosimilar
• 63.9% reported switching to a trastuzumab biosimilar with Kanjinti being most common (69.8%)
• 40.8% of patients said they received no prior notification about the switch
• No oncologists reported that the decision to switch a patient to a biosimilar was initiated by them
  • 45.2% said it was initiated by the insurer, 29.0% by the pharmacy; and 19.4% by the hospital/center administration

According to the authors, some patients noticed on their own that they had been switched by reading it in their chart or insurance papers. “This is evidence for a lack of consistent processes in how health care systems are managing communication with patients regarding switches to trastuzumab biosimilars, a systems-level issue,” the authors wrote.

Overall, patients reported a less positive experience with trastuzumab biosimilars than oncologists reported about their perception of patient experiences. The majority (61.0%) of patients said they learned about biosimilars through self-directed learning. A smaller proportion reported learning about biosimilars through a conversation with their health care provider vs asking on social media (33.3% vs 35.2%).

While 58.8% of oncologists agreed that “The patient had the opportunity to ask questions about a switch to biosimilar trastuzumab” only 35.3% of patients responded the same. In fact, 55.6% of patients reported wanting to have time to discuss biosimilars with their physician and 52.5% wanted to achieve a better understanding of biosimilars.

Another area where the experiences differed was the statement “The cancer is/will be treated as effectively with biosimilar trastuzumab” for which 79.4% of oncologists agreed compared with only 43.4% of patients.

“We highlighted a discrepancy between patient-reported experiences and oncologist perceptions of the patient experience, suggesting that lack of adequate information is a challenge not only to the uptake of trastuzumab biosimilars, but to the patient-oncologist relationship,” the authors concluded.

Among the limitations of the study, the authors noted that the patient sample was mostly White and there is a possibility that the sample was biased with patients who experienced challenges with trastuzumab biosimilars choosing to participate in the survey.

Reference

Lerner Papautsky E, Carlson M, Johnson SM, Montague H, Attai DJ, Lustberg MB. Characterizing experiences of non-medical switching to trastuzumab biosimilars using data from internet-based surveys with US-based oncologists and breast cancer patients. Breast Cancer Res Treat. Published online May 14, 2022. doi:10.1007/s10549-022-06615-2