• Lead drug candidate is a highly potent and selective CDK4/6 inhibitor
• Data expected by early 2015
• Initiation of Phase 1b/2a trial in oncology patients expected in second quarter of 2015

RESEARCH PARK TRIANGLE, NC, September 10, 2014 – G1 Therapeutics, Inc., a privately held, clinical-stage pharmaceutical company, today announced the initiation of a Phase 1 clinical trial of G1T28-1, a highly potent and selective CDK4/6 inhibitor with broad potential in multiple oncology indications.

The randomized, placebo-controlled, single ascending dose study will assess the safety, pharmacokinetics and pharmacodynamics of G1T28-1 in healthy volunteers. The study is being conducted in collaboration with PRA Health Sciences and is currently enrolling subjects in the Netherlands.  Data collected from the study will inform dose and schedule for further development of G1T28-1, either as a bone marrow chemoprotectant or as an antineoplastic agent.

“G1T28-1 is a first-in-class therapy for protecting the bone marrow from chemotherapy-induced myelosuppression in patients with CDK4/6-independent tumors, and has the potential to be best-in-class as an antineoplastic agent in patients with CDK4/6-dependent tumors,” said Raj Malik, MD, Chief Medical Officer of G1.  “Preclinical data demonstrate that G1T28-1 is differentiated from currently available therapies for myelosuppression in that it protects all hematopoietic lineages, including red cells, platelets, granulocytes and lymphocytes, before damage is done by chemotherapy.”

“With our lead program now in the clinic, G1 has reached a key inflection point,” said Mark Velleca, MD, PhD, Chief Executive Officer of G1.  “We are excited to advance G1T28-1 through clinical development and demonstrate its potential in multiple oncology indications.”

About G1 Therapeutics, Inc.

G1 Therapeutics, Inc. is a privately held, clinical-stage pharmaceutical company based in Research Triangle Park, NC that is developing small-molecule therapies to address significant unmet needs in oncology.  G1’s proprietary compounds target specific proteins associated with cell proliferation and have demonstrated robust anti-tumor efficacy and unique chemoprotection activity in animal models.  In October 2013, the company raised $12.5 million in a Series A financing that has enabled it to advance its pipeline of lead compounds and bring its drug candidate, G1T28-1, into clinical trials.

Visit www.g1therapeutics.com for more information.