• • Proceeds to accelerate clinical development of lead CDK4/6 inhibitor for antineoplastic and chemoprotection indications

• Fred Eshelman and Peter Kolchinsky join board of directors

RESEARCH TRIANGLE PARK, N.C., Feb. 5, 2015 (GLOBE NEWSWIRE) — G1 Therapeutics, Inc., a clinical-stage pharmaceutical company developing small-molecule therapies to address significant unmet needs in oncology, today announced the completion of a $33 million Series B financing round. Lead investors Eshelman Ventures and RA Capital Management were joined by new investors Lumira Capital and Boxer Capital of Tavistock Life Sciences, as well as the company’s existing investors Hatteras Venture Partners, MedImmune Ventures, and Mountain Group Capital. Fred Eshelman, PharmD, Founder of Eshelman Ventures, and Peter Kolchinsky, PhD, Managing General Partner of RA Capital, have joined G1’s board of directors.

G1 plans to use the proceeds to advance its lead program G1T28, a highly potent and selective CDK4/6 inhibitor, through proof of concept as an antineoplastic agent and as a bone marrow chemoprotectant. G1T28 is currently being evaluated in Phase 1a clinical trials to assess safety, pharmacokinetics, and pharmacodynamics in healthy volunteers. Data collected from this study will inform the dose and schedule for multiple Phase 1b / 2a clinical trials in cancer patients, which are expected to begin in 2015.

“This financing from new and existing investors is a testament to G1T28’s potential in multiple oncology indications,” said Mark Velleca, MD, PhD, Chief Executive Officer of G1. “We’re especially fortunate to have Fred and Peter on our board, as their business acumen and scientific expertise will be invaluable as we advance G1T28 through the clinic.”

Fred Eshelman said, “I’m delighted to be involved with a growing company that originated from the University of North Carolina. G1’s strong leadership team, seasoned advisors, and pipeline of proprietary drug candidates position the company to be a key player in oncology.”

Peter Kolchinsky added, “Rarely does an entirely novel, orthogonal mechanism emerge in oncology that has the ability to combine with other approaches. There are many inhibitors of angiogenesis, immune evasion, DNA replication, and growth signaling. Shutting down the G1/S cell cycle transition via precise CDK4/6 inhibition is now emerging as a category unto itself, and G1 Therapeutics is the only small company with a selective agent in the clinic. While three pharmas are ahead and have done much to validate this class, we expect significant interest from the many others that already appreciate — or soon will — that they have a gap in their toolkit.”

About G1 Therapeutics, Inc.

G1 Therapeutics, Inc. is a privately held clinical-stage pharmaceutical company based in Research Triangle Park, NC that focuses on the discovery and development of novel small-molecule therapies to address significant unmet needs in oncology. The company is leveraging its proprietary kinase drug discovery platform to advance a pipeline of first-in-class compounds and best-in-class drug candidates that address two markets: CDK4/6 antineoplastics and protection of the bone marrow from damage by chemotherapy (chemoprotection). The company’s lead program, G1T28, is a highly potent and selective CDK4/6 inhibitor that is currently being evaluated in Phase 1a clinical trials.

Visit www.g1therapeutics.com for more information.

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

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