General Information

Cosela (trilaciclib) is a kinase inhibitor.

Cosela is specifically indicated to decrease the incidence of chemotherapy-induced myelosuppression in adult patients when administered prior to a platinum/etoposide-containing regimen or topotecan-containing regimen for extensive-stage small cell lung cancer.

Cosela is supplied as an injection for intravenous administration. The recommended dose of Cosela is 240 mg/m2 per dose. Administer as a 30-minute intravenous infusion completed within 4 hours prior to the start of chemotherapy on each day chemotherapy is administered. The interval between doses of Cosela on sequential days should not be greater than 28 hours. If the Cosela dose is missed, discontinue chemotherapy on the day the Cosela dose was missed. Consider resuming both Cosela and chemotherapy on the next scheduled day for chemotherapy. If Cosela is discontinued, wait 96 hours from the last dose of Cosela before resumption of chemotherapy only.

Mechanism of Action 

Cosela (trilaciclib) is a transient inhibitor of CDK 4 and 6. Hematopoietic stem and progenitor cells (HSPCs) in the bone marrow give rise to circulating neutrophils, RBCs, and platelets. HSPC proliferation is dependent on CDK4/6 activity.

Side Effects

Adverse effects associated with the use of Cosela may include, but are not limited to, the following:

• fatigue
• hypocalcemia
• hypokalemia
• hypophosphatemia
• aspartate aminotransferase increased
• headache
• pneumonia

Clinical Trial Results

The FDA approval of Cosela was based on three randomized, double-blind, placebo-controlled trials in patients with extensive stage-small cell lung cancer (ES-SCLC). 

Study 1 (G1T28-05) was a randomized (1:1), double-blind, placebo-controlled study of Cosela or placebo administered prior to treatment with etoposide, carboplatin, and atezolizumab (E/P/A) for patients with newly diagnosed ES-SCLC not previously treated with chemotherapy. A total of 107 patients were randomized to receive Cosela (n=54) or placebo (n=53) prior to administration of E/P/A. The study demonstrated a statistically significantly shorter duration of severe neutropenia (DSN) in Cycle 1 (0 vs 4 days) and a lower proportion of patients with severe neutropenia (SN) (2% vs 49%) in patients receiving Cosela compared with placebo. Nineteen percent of patients receiving Cosela had Grade 3 or 4 decreased hemoglobin compared with 28% of patients receiving placebo. The rate of RBC transfusions over time was 1.7/100 weeks for patients receiving Cosela and 2.6/100 weeks for patients receiving placebo. Six percent of patients receiving Cosela received erythropoiesis-stimulating agents (ESAs) compared with 11% of patients receiving placebo.

Study 2 (G1T28-02) was a randomized (1:1), double-blind, placebo-controlled evaluation of Cosela or placebo administered prior to treatment with etoposide and carboplatin (E/P) for patients with newly diagnosed ES-SCLC not previously treated with chemotherapy. A total of 77 patients were randomized to Cosela (n=39) or placebo (n=38) and stratified by ECOG performance status (0 to 1 vs 2). Ten percent of patients receiving Cosela had Grade 3 or 4 decreased hemoglobin compared with 18% of patients receiving placebo. The rate of RBC transfusions over time was 0.5/100 weeks for patients receiving Cosela and 1.9/100 weeks for patients receiving placebo. Three percent of patients receiving Cosela received ESAs compared with 5% of patients receiving placebo.

Study 3 (G1T28-03) included a randomized, double-blind, placebo-controlled evaluation of Cosela or placebo administered prior to topotecan in patients with ES-SCLC previously treated with chemotherapy. A total of 61 patients were randomized to Cosela (n=32) or placebo (n=29). Thirty-eight percent of patients receiving Cosela had Grade 3 or 4 decreased hemoglobin compared with 59% of patients receiving placebo. The rate of RBC transfusions over time was 2.6/100 weeks for patients receiving Cosela and 6.3/100 weeks for patients receiving placebo. Three percent of patients receiving Cosela received ESAs compared with 21% of patients receiving placebo.