Trilaciclib (G1T28), a CDK 4/6 Inhibitor, in Combination With Etoposide and Carboplatin in Extensive Stage Small Cell Lung Cancer (SCLC)

Phase 1b/2a Safety and Pharmacokinetic Study of G1T28 in Patients With Extensive Stage Small Cell Lung Cancer (SCLC) Receiving Etoposide and Carboplatin

This is 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 etoposide in first line treatment for patients with newly diagnosed extensive-stage SCLC.

The study consists of 2 parts: a limited open-label, dose-finding portion (Part 1), and a randomized double-blind portion (Part 2). Both parts include 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. Approximately, 90 patients will be enrolled in the study; 20 patients in the Part 1 and 70 patients in the Part 2 portion.

Inclusion Criteria:

• Male or female subjects aged ≥18 years
• Unequivocally confirmed diagnosis of SCLC by histology or cytology, preferably including the presence of neuroendocrine features by immunohistochemistry
• At least 1 target lesion that is unirradiated and measurable by RECIST, Version 1.1
• Eastern Cooperative Oncology Group (ECOG) performance status of 0 - 2
• Adequate organ function

Exclusion Criteria:

• Prior chemotherapy for extensive-stage SCLC
• Presence of symptomatic brain metastases requiring immediate treatment with radiation therapy or steroids.
• Uncontrolled ischemic heart disease or uncontrolled symptomatic congestive heart failure
• Known history of stroke or cerebrovascular accident within 6 months prior to enrollment
• Other uncontrolled serious chronic disease or conditions that in the investigator's opinion could affect compliance or follow-up in the protocol
• Concurrent radiotherapy to any site or radiotherapy within 2 weeks prior to enrollment or previous radiotherapy to the target lesion sites (the sites that are to be followed for determination of a response)
• Receipt of any investigational medication within 4 weeks prior to enrollment