Safety and efficacy of amrubicin with primary prophylactic pegfilgrastim as second-line chemotherapy in patients with small cell lung cancer

Background: Amrubicin (AMR) regimens have shown efficacy as second-line treatment in patients with small cell lung cancer (SCLC); however, adverse events such as febrile neutropenia (FN) sometimes preclude their use. Further, the safety and efficacy of AMR with primary prophylactic pegfilgrastim (P-PEG) have not been sufficiently evaluated. In this study, we evaluated the safety and efficacy of AMR with or without P-PEG as second-line chemotherapy for SCLC. Methods: We retrospectively reviewed patients with SCLC who received AMR as second-line chemotherapy at Shizuoka Cancer Center, between December 2014 and November 2021. Based on presence/absence of P-PEG in their regimen, patients (n = 60) were divided into P-PEG (n = 21) and non-P-PEG groups, and their clinical outcomes were evaluated. Results: Median of AMR treatment cycles was five (range: 1–39 cycles) in P-PEG group and four (range: 1–15 cycles) in non-P-PEG group. The incidence of FN (4.8% vs. 30.8%; p = 0.02) and AMR dose reduction because of adverse events (4.8% vs. 25.6%; p = 0.08) were lower in the P-PEG group than in the non-P-PEG group. The objective response rates were 52.4% and 30.8%, and median progression-free and overall survival were 4.7 and 3.0 months, and 9.6 and 6.8 months, in the P-PEG and non-P-PEG groups, respectively. Conclusions: AMR with P-PEG as second-line chemotherapy for SCLC reduced the incidence of FN at a maintained AMR dose intensity and was associated with favorable tumor responses and survival outcomes. P-PEG should be considered for patients treated with AMR for SCLC including refractory relapsed SCLC.