OBJECTIVES: Real-world evidence on the clinical effectiveness of pegfilgrastim biosimilars are limited. This study compared the incidence of febrile neutropenia (FN) between pegfilgrastim biosimilars (pegfilgrastim-jmdb, pegfilgrastim-cbqv) and originator users.

METHODS: A retrospective cohort study using 2019 IBM MarketScan Commercial and Medicare Supplemental database was conducted in adult patients with cancer initiating myelosuppressive chemotherapy courses. At least 2 cancer diagnoses (at least 7 days apart within +/- 30 days of the initiation) were required. The following exclusion criteria were applied: (1) ≥2 solid cancers; (2) acute myeloid leukemia; (3) autologous peripheral blood progenitor cell collection; (4) bone marrow transplantation; (5) using pegfilgrastim on-body-injector/with unknown route; (6) using more than 1 granulocyte-colony stimulating factors product. Cumulative incidence of FN associated hospitalization was measured by ICD-10 diagnosis codes (neutropenia, fever, or infection) in the first cycle. After 1:1 propensity score (PS) matching, we compare FN risk between biosimilars and originator users using equivalence (with a margin of 6%) and superiority hypothesis tests.

RESULTS: A total of 2,045 patients were included (445 used pegfilgrastim-jmdb, 636 used pegfilgrastim-cbqv, and 964 used pegfilgrastim originator). After PS matching, 13 out of 445 originator users and 17 out of 445 pegfilgrastim-jmdb users developed FN (risk difference was 0.9%; p-value was 0.4575 for superiority test indicating no difference ;p-value was <0.0001 for equivalence test indicating statistical equivalence). After PS matching, 14 out of 633 originator users and 16 out of 633 pegfilgrastim-cbqv users developed FN (risk difference was 0.32%; p-value was 0.7117 for superiority test indicating no difference; p-value was <0.0001 for equivalence test indicating statistical equivalence).

CONCLUSIONS: In this real-world study of patients with cancer receiving myelosuppressive chemotherapy, there was no difference in FN risk between patients receiving pegfilgrastim originator and biosimilars in the first cycle.