Phase 2 Study of the Safety, Efficacy, and Pharmacokinetics of G1T28 in Patients With Metastatic Triple Negative Breast Cancer Receiving Gemcitabine and Carboplatin Chemotherapy

This was a study to investigate the potential clinical benefit of trilaciclib (G1T28) in preserving the bone marrow and the immune system, and enhancing chemotherapy antitumor efficacy when administered prior to carboplatin and gemcitabine (GC therapy) for participants with metastatic triple negative breast cancer. The study was an open-label and 102 participants were randomly assigned (1:1:1 fashion) to 1 of the 3 following treatment groups: * Group 1: GC therapy (Days 1 and 8 of 21-day cycles) only (n=34) * Group 2: GC therapy (Days 1 and 8) plus trilaciclib (G1T28) on Days 1 and 8 of 21-day cycles (n=33) * Group 3: GC therapy (Days 2 and 9) plus trilaciclib (G1T28) on Days 1, 2, 8, and 9 of 21-day cycles (n=35) The study included 3 study phases: Screening Phase, Treatment Phase, 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.