Myeloprotection effects of trilaciclib in Chinese patients with extensive stage small cell lung cancer (ES-SCLC) receiving chemotherapy-a real-world study.

Background: Trilaciclib, an intravenous short acting cyclin-dependent kinase 4/6 inhibitor, has been approved for the prevention of chemotherapy-induced myelosuppression (CIM) in patients with extensive stage small cell lung cancer (ES-SCLC) receiving platinum/etoposide (EP) or topotecan (TPT)-based therapy in United States (US) since February 2021. Trilaciclib use received the priority review and approval in a real-world setting in China. This study thus aimed to collect real-world data and evaluate the protective effect of trilaciclib on CIM in Chinese patients with ES-SCLC. Methods: This single-arm, noninterventional real world study invited all patients with ES-SCLC who received trilaciclib with the platinum and etoposide ± anti-programmed cell death ligand-1 [anti-PD-(L)1] antibodies (EP group) or trilaciclib with TPT (TPT group) in Boao, Hainan China to participate in the study. The primary endpoint was the incidence of the severe (grade four) neutropenia (SN), and the secondary endpoints included other myeloprotection effects, safety and anti-tumor activity. Results: Between August 2021 and December 2022, a total of 30 patients who received trilaciclib with chemotherapy consented to participate in this real-world study. Among the enrolled patients, 26 patients were treated with EP regimen, of these, 18 patients were combined with anti-PD-(L)1 antibodies, and 4 patients were treated with TPT. The incidence of SN was 6.7%, with one patient each in EP group and TPT group. The incidence of grade three hematological toxicities was 30% (9/30), with 19.2% (5/26) in the EP group, and 100% (4/4) in the TPT group. The incidence of grade four hematological toxicities was 5/30 (16.7%), with 3/26 (11.5%) and 2/4 (50%) in EP and TPT group, respectively. Overall, the incidence of those who received intravenous or oral antibiotics was 6/30 (20%), with 4/26 (15.4%) in the EP group, and 2/4 (50%) in the TPT group. No ≥ grade three adverse events, serious adverse events (SAEs), and adverse events of special interest associated with trilaciclib were reported. Conclusions: Trilaciclib decreased the incidence of CIM in Chinese patients when administered prior to an EP-containing regimen [combined with or without PD-(L)1] or TPT for ES-SCLC. The effect of myeloprotection, anti-tumor and safety were all consistent with the studies conducted globally and data from the Chinese Phase three placebo-controlled study (TRACES).