The preliminary findings of a retrospective study that analyzed healthcare claims from the Biologics and Biosimilars Collective Intelligence Consortium’s Distributed Research Network between 2016 and 2020 indicate that utilization of biosimilar trastuzumab-anns increased over time, whereas the use of trastuzumab reference decreased.
A retrospective study assessed utilization and patient characteristics of the trastuzumab reference, trastuzumab biosimilars, and other HER2 inhibitors; these results were reported at the 2021 American Society of Clinical Oncology Annual Meeting.
This study used the FDA’s Sentinel Initiative distributed analysis tools to analyze healthcare claims from the Biologics and Biosimilars Collective Intelligence Consortium’s Distributed Research Network of >95 million persons. The analysis identified claims from October 1, 2016, to February 29, 2020 (end date varied across health plans); full data were not available for 2019 to 2020 for all health plans. For each HER2 inhibitor, descriptive analyses were conducted on the number of incident users and patient characteristics. Eligibility criteria included adults who had continuous medical and drug coverage ≥365 days prior to their HER2 inhibitor use.
A total of 6631 patients were treated with trastuzumab reference, 122 patients with trastuzumab-anns, 116 patients with ado-trastuzumab emtansine, 54 patients with neratinib, 54 patients with lapatinib, 11 patients with trastuzumab-dkst, and 11 patients with trastuzumab/hyaluronidase-oysk. The mean age was similar between the trastuzumab reference (52.5 years) and biosimilar (59.0 years) groups. Over the study period, a decrease in the number of incident users/100,000 person-years of the trastuzumab reference was reported, with 13.5 in 2016 and 9.4 in 2020. By contrast, the number of incident users/100,000 person-years increased for trastuzumab-anns from 0.4 in 2019 to 4.9 in 2020.
Variation was seen in clinical characteristics between HER2 inhibitors and by metastatic status, whereas the characteristics were generally similar between trastuzumab reference and trastuzumab-anns during the baseline period. For example, the Charlson/Elixhauser comorbidity score was the highest for lapatinib (2.0), lowest for neratinib (0.5), and similar between the trastuzumab originator (1.1) and trastuzumab-anns (1.3) groups. In terms of chemotherapy use, 38.9% received chemotherapy for lapatinib, 18.5% for trastuzumab reference, and 14.8% for trastuzumab-anns. Endocrine therapy use was 63% for neratinib, 11.1% for trastuzumab originator, and 10.7% for trastuzumab-anns. Among incident users with metastatic breast cancer, endocrine therapy receivers during the baseline period accounted for 19.3% for the trastuzumab originator and 69.6% for lapatinib.
The preliminary findings of the study indicate that utilization of biosimilar trastuzumab-anns increased over time, whereas the use of trastuzumab reference decreased.
Source: Nam YH, Mendelsohn A, Marshall J, et al. Utilization and patient characteristics for the trastuzumab originator, biosimilars, and other HER2 inhibitors in the United States. J Clin Oncol. 2021;39(suppl_28):308.