Trilaciclib — Drug Monograph

Brand names: Cosela

Drug class: CDK4/6 Inhibitor

Mechanism of Action

Intravenous cyclin-dependent kinase 4/6 (CDK4/6) inhibitor given transiently before chemotherapy to arrest hematopoietic stem and progenitor cells in the G1 phase of the cell cycle. Because these cells are held out of the S phase during chemotherapy exposure, they are protected from chemotherapy-induced DNA damage — a myeloprotective strategy distinct from the antitumor use of CDK4/6 inhibitors in breast cancer.

FDA Indications

• To decrease the incidence of chemotherapy-induced myelosuppression in adults receiving a platinum/etoposide-containing or topotecan-containing regimen for extensive-stage small cell lung cancer (FDA approved 2021)

Common Side Effects

• Fatigue
• Hypocalcemia
• Hypokalemia
• Hypophosphatemia
• Increased aspartate aminotransferase
• Headache
• Pneumonia

Clinical Pearl

Unlike the antitumor CDK4/6 inhibitors, trilaciclib is proactive myeloprotection: given immediately before chemotherapy in extensive-stage SCLC to reduce neutropenia, anemia, and the need for growth factors and transfusions. It is not itself an anticancer agent and must be completed within 4 hours before chemotherapy.

Related Therapies & Mechanisms

• Abemaciclib (Verzenio) — CDK4/6 Inhibitor
• Palbociclib (Ibrance) — CDK4/6 Inhibitor
• Ribociclib (Kisqali) — CDK4/6 Inhibitor
• Atezolizumab (Tecentriq) — SCLC