December 5, 2016

G1 Therapeutics to Evaluate Trilaciclib (G1T28) in Combination with Immune Checkpoint Inhibitor in Small-Cell Lung Cancer

Phase 2 study evaluating potential of Genentech’s Tecentriq plus trilaciclib and chemotherapy as a first-line treatment for small-cell lung cancer patients expected to begin in first half of 2017

RESEARCH TRIANGLE PARK, N.C., Dec. 05, 2016 (GLOBE NEWSWIRE) — G1 Therapeutics, Inc. a clinical-stage oncology company, announced today a clinical trial collaboration with Genentech, a member of the Roche Group. A Phase 2 clinical trial is expected to begin in the first half of 2017 and will evaluate the combination of Genentech’s immune checkpoint, anti-PD-L1 antibody Tecentriq® (atezolizumab) with G1’s CDK4/6 inhibitor trilaciclib (G1T28) as a first-line treatment for patients with small-cell lung cancer (SCLC) receiving chemotherapy.

Trilaciclib is a potential first-in-class, short-acting intravenous CDK4/6 inhibitor in development to preserve hematopoietic stem cells and enhance immune system function during chemotherapy. Tecentriq is an anti-PD-L1 monoclonal antibody designed to bind to PD-L1 expressed on tumor cells and tumor-infiltrating immune cells, blocking its interactions with both PD-1 and B7.1 receptors. The Phase 2 study will explore the potential affects of the combination with trilaciclib on the efficacy of anti-PD-L1 inhibition given with chemotherapy in patients with newly diagnosed SCLC.

Preliminary results from two ongoing Phase 1b/2a trials of trilaciclib in combination with chemotherapy in SCLC have demonstrated anti-tumor activity, including a complete response and multiple partial responses. The treatment has been well-tolerated with no febrile neutropenia. In preclinical studies, trilaciclib significantly increased efficacy and overall survival in combination with oxaliplatin and anti-PD-L1 in syngeneic mouse-tumor models.

“We are excited that this combination regimen of trilaciclib plus Tecentriq may benefit patients with small-cell lung cancer, a disease with tremendous unmet medical need,” said Mark Velleca, MD, PhD, Chief Executive Officer of G1 Therapeutics. “Trilaciclib has demonstrated its ability to preserve the immune system from damage by chemotherapy and to enhance T cell activation, which may augment anti-tumor immunity and be a powerful complement to Tecentriq.”

Financial terms of the non-exclusive collaboration have not been disclosed.

About Trilaciclib

Trilaciclib (G1T28) is a potential first-in-class, short-acting IV CDK4/6 inhibitor being developed to preserve hematopoietic stem cells and enhance immune system function during chemotherapy. Trilaciclib has the potential to significantly improve the treatment outcomes of patients receiving chemotherapy.

Trilaciclib is being studied in two Phase 1b/2a proof-of-concept trials in patients with small-cell lung cancer: a study in newly diagnosed, treatment-naive patients (NCT02499770), and a study in previously treated patients (NCT02514447).

About G1 Therapeutics, Inc.

G1 Therapeutics is a clinical-stage oncology company developing novel, small-molecule therapies that address significant unmet needs in people with cancer. The company is advancing a pipeline of potential best-in-class and first-in-class drug candidates in multiple oncology indications. G1 is privately held and based in Research Triangle Park, NC.

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G1 Investor Contact: Mark Velleca, MD, PhD G1 Therapeutics 919-213-9838 [email protected]

G1 Media Contact: Laura Bagby 6 Degrees Communications 312-448-8098 [email protected]