Phase 2 Study of Carboplatin, Etoposide, and Atezolizumab With or Without Trilaciclib in Patients With Untreated Extensive Stage Small Cell Lung Cancer

This is a study to investigate the potential clinical benefit of trilaciclib (G1T28) in
preserving the bone marrow and the immune system, and enhancing antitumor efficacy when
administered with carboplatin, etoposide, and atezolizumab (E/P/A) therapy in first line
treatment for patients with newly diagnosed extensive-stage SCLC.

The study is a randomized, double-blinded, placebo-controlled design. The study will include
3 study phases: Screening Phase,Treatment Phase (induction part + maintenance part), and
Survival Follow-up Phase. The Treatment Phase begins on the day of first dose with study
treatment and completes at the Post-Treatment Visit. Approximately, 100 patients will be
enrolled in the study.