Efficacy and Safety of Trilaciclib for the Prevention of Chemotherapy-Induced Myelosuppression in Patients With Solid Tumors: A Systematic Review and Meta-Analysis

Trilaciclib, a cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitor administered before chemotherapy, reduces chemotherapy-induced myelosuppression (CIM) in extensive-stage small cell lung cancer (ES-SCLC), but its efficacy across solid tumors remains unclear. This meta-analysis evaluated the efficacy and safety of trilaciclib in solid tumor patients receiving chemotherapy. PubMed, Embase, Cochrane Library, and ClinicalTrials.gov were searched from inception to January 21, 2026. Randomized controlled trials (RCTs) and cohort studies comparing chemotherapy with or without trilaciclib were included. Primary outcomes were severe neutropenia (SN), febrile neutropenia (FN), duration of severe neutropenia (DSN), Grade 3/4 leukopenia, and granulocyte colony-stimulating factor (G-CSF) use. Secondary outcomes included other hematologic toxicities, supportive care interventions, and efficacy outcomes. Ten studies involving 1172 patients (six RCTs and four cohort studies) were identified. Trilaciclib significantly reduced SN (OR, 0.14; 95% CI, 0.06-0.31; p < 0.001), FN (OR, 0.19; 95% CI, 0.11-0.36; p < 0.001), Grade 3/4 leukopenia (OR, 0.25; 95% CI, 0.13-0.46; p < 0.001), and G-CSF use (OR, 0.36; 95% CI, 0.18-0.71; p = 0.0087), and shortened DSN (MD, -2.30 days; 95% CI, -4.28 to -0.31; p = 0.0309). It also reduced Grade 3/4 anemia and thrombocytopenia and decreased use of erythropoiesis-stimulating agents, red blood cell transfusions, and platelet transfusions. Overall survival showed a borderline improvement (HR, 0.84; 95% CI, 0.71-0.99; p = 0.0373), while no significant differences were observed in progression-free survival, overall response rate, or non-hematologic adverse events. Subgroup analyses suggested greater benefit in ES-SCLC. Overall, trilaciclib before chemotherapy significantly reduced CIM and supportive care needs, with no apparent compromise in antitumor efficacy and more pronounced effects in ES-SCLC.