The aim of this study is to investigate the safety and efficacy of the prophylactic use of Trilaciclib in patients with non-small cell lung cancer (NSCLC) receiving platinum-based chemotherapy, so as to provide more evidence-based medical evidence for the optimal diagnosis and treatment strategy in this population.

This is a single-arm, exploratory clinical study. Eligible patients were treated with Trilaciclib before the first cycle of chemotherapy, and their peripheral blood samples were tested on days 3,7,14,21±1 after chemotherapy. At the same time, the incidence of FN, the use of antibiotics, the safety, the number of patients who delayed the second cycle of treatment, the number of patients who reduced the dose of chemotherapy, the number of patients who reduced the dose of chemotherapy due to neutropenia, and the number of patients who discontinued chemotherapy were observed.

Inclusion Criteria:

• Age above 18 years old (including 18 years old)，regardless of gender；
• ECOG-PS score of 0-1,；
• expected survival≥12 weeks；
• There was no tumor deterioration in the 2 weeks prior to study drug treatment.
• Advanced non-small cell lung cancer without systemic chemotherapy.
• At least one tumor lesion with a maximum diameter ≥10 mm (short diameter ≥15 mm if it is a lymph node) that could be measured accurately at baseline according to RECIST1.1 criteria. Baseline tumor imaging was performed within 28 days before the first dose.
• Women of childbearing age should use appropriate contraception and should not breastfeed from screening until 3 months after discontinuation of study treatment.
• Male subjects should use barrier contraception (i.e., condoms) for 3 months from screening until discontinuation of study treatment.
• All subjects voluntarily participated and signed the informed consent form in person.

Exclusion Criteria:

• Uncontrolled ischemic heart disease or clinically significant congestive heart failure (NYHA class III or IV);
• stroke or cardio-cerebrovascular event within 6 months before enrollment;
• QTcF interval > 480msec at screening or > 500msec for patients with implanted ventricular pacemakers;
• Previous hematopoietic stem cell or bone marrow transplantation;
• Allergy to the study drug or its components;
• Others considered by the investigator to be unsuitable for this study.