Application value and safety of trilaciclib in first‑line chemotherapy combined with immunotherapy for  extensive‑stage small cell lung cancer: A real‑world study

The present study is a single-center, retrospective real-world study that aimed to evaluate the myeloprotective effect, safety and impact on survival prognosis of trilaciclib in first-line chemotherapy combined with immunotherapy for patients with extensive-stage small cell lung cancer (ES-SCLC) in China. A total of 180 newly diagnosed patients with ES-SCLC who received first-line chemotherapy combined with immunotherapy at Chengde Central Hospital from January 2020 to January 2024 were included. Patients were divided into two groups based on whether they received trilaciclib: The trilaciclib group (n=90) and the control group (n=90). Baseline characteristics were matched between the two groups, and treatment regimens were identical, with only the trilaciclib group receiving trilaciclib before chemotherapy. Differences between the groups were compared in terms of myelosuppression-related adverse reactions, chemotherapy completion rates, efficacy [objective response rate (ORR), disease control rate] and survival outcomes [progression-free survival (PFS), overall survival (OS)]. Statistical Package for the Social Sciences 26.0 was used for statistical analysis. The trilaciclib group showed significant advantages over the control group in terms of myelosuppression, including a lower incidence of grade 3-4 neutropenia (17.7 vs. 65.6%; P<0.001), anemia (≥grade 3; 15.6 vs. 30.0%; P=0.021), and thrombocytopenia (≥grade 3; 11.1 vs. 25.6%; P=0.012). Furthermore, the usage rate of granulocyte colony-stimulating factor, the incidence of febrile neutropenia and hospitalization rates due to myelosuppression were significantly lower in the trilaciclib group compared with the control group (P<0.01). The rate of chemotherapy delay, dose adjustment, and interruption was significantly lower in the trilaciclib group compared with the control group, with a greater number of cycles completed on average in the trilaciclib group (5.3±0.7 vs. 4.1±1.9; P=0.037). In terms of efficacy, the ORR in the trilaciclib group was higher than the control group (86.7 vs. 75.6%), although the difference did not reach statistical significance (P=0.057). Survival analysis showed that the median PFS in the trilaciclib group was 6.7 months, significantly higher than the 5.3 months of the control group [hazard ratio (HR)=0.677; 95% confidence interval, 0.502-0.912; P=0.0075)]. The median OS was 15.1 months in the trilaciclib group and 12.8 months in the control group, with no statistically significant difference (P=0.0886). The 1-, 2- and 3-year OS rates for the trilaciclib group were 63.3, 42.2 and 17.8%, respectively, with a 1-year PFS rate of 28.9%, all higher than the control group. Multivariate analysis identified an Eastern Cooperative Oncology Group (ECOG) performance status of 1 (HR=1.837; P=0.004), >3 metastatic sites (HR=7.392; P<0.001) and the presence of baseline brain metastasis (HR=2.196; P<0.001) as independent adverse prognostic factors for OS. For PFS, both the number of metastatic sites and treatment modality were independent predictors, with patients in the control group having a significantly higher risk of progression compared with those receiving trilaciclib (HR=1.495; P=0.008). These findings indicated that trilaciclib significantly reduced myelosuppression-related adverse events in first-line chemotherapy combined with immunotherapy for ES-SCLC, improved chemotherapy adherence and prolonged progression-free survival (PFS). No statistically significant difference in OS was observed between the trilaciclib and control groups. The 3-year OS rates were 17.8% for the trilaciclib group and 11.1% for the control group, with a low absolute difference of 6.7%. The number of metastatic sites and treatment method were independent influencing factors for PFS, while ECOG score and baseline brain metastasis were independent poor prognostic factors for OS. In summary, trilaciclib is a potentially promising myeloprotective agent that improves PFS without compromising overall survival in patients with ES-SCLC.