Efficacy of amrubicin after immuno-chemotherapy for extensive-stage small-cell lung cancer

Although immuno-chemotherapy has been widely used for extensive-stage small-cell lung cancer (ES-SCLC), the efficacy of amrubicin as second-line therapy after immuno-chemotherapy remains unclear. We retrospectively collected data of patients received amrubicin as second-line chemotherapy among 17 ES-SCLC patients received immuno-chemotherapy as first-line from October 2019 to January 2021 in Kanagawa Cancer Center, focusing on time from the last day of first-line platinum therapy to first-line PD, objective response, and safety. Seven of 17 patients were treated with amrubicine as second-line chemotherapy. The median age was 69 years (59-78). The median time from the last platinum dose to first-line PD was 61 days (40-125), and two patients had more than 90 days. The initial dose of amrubicin was 30 mg/m2 in 2 patients, 35 mg/m2 in 1 patient, and 40 mg/m2 in 4 patients, and 2 patients received primary prophylactic PEG-G-CSF. Serious adverse events included grade 4 neutropenia in 4 patients, febrile neutropenia in 1 patient, and grade 3 pneumonitis in 1 patient. One patient (14.3%) had PR, 1 patient (14.3%) had SD, and 5 patients (71.4%) had PD. PR patient received 6 cycles, SD patient received 4 cycles, and PD patients received 1-3 cycles of amrubicin. No response was seen in patients who had PD on first-line therapy within 90 days of the last platinum dose. Second-line amrubicin therapy following immuno-chemotherapy seemed to have lower response.