G1 Therapeutics Provides First Quarter 2018 Corporate and Financial Update

• U.S. and European regulatory meetings scheduled based on positive trilaciclib Phase 2a myelopreservation data

• Preliminary data from G1T38 Phase 1b trial in breast cancer to be presented at ASCO on June 2

• Management to host webcast and conference call today at 4:30 p.m. ET

RESEARCH TRIANGLE PARK, N.C., May 03, 2018 (GLOBE NEWSWIRE) -- G1 Therapeutics, Inc. GTHX, a clinical-stage oncology company, today provided an update on its corporate activities, product pipeline and financials for the first quarter ended March 31, 2018.

"We are pleased that both of our CDK4/6 inhibitor clinical programs continue to show promise in improving patient outcomes. Based on the positive trilaciclib Phase 2a data in first-line small cell lung cancer that we reported in March, we look forward to meetings with U.S. and European regulators to continue to gather feedback on our development program. Our regulatory strategy will also be informed by results from Phase 2 trials in second- / third-line small cell lung cancer and triple-negative breast cancer, which we expect in the fourth quarter of this year," said Mark Velleca, M.D., Ph.D., Chief Executive Officer. "We are presenting the first clinical data on G1T38, our oral CDK4/6 inhibitor, in patients with ER+, HER2- breast cancer at the upcoming American Society of Clinical Oncology Annual Meeting. We are encouraged by the preliminary Phase 1b results and believe that G1T38 could have a best-in-class profile."

First Quarter 2018 and Recent Corporate Highlights

• Reported positive trilaciclib Phase 2a topline data showing robust myelopreservation benefits in patients with small cell lung cancer (SCLC): In March, G1 announced data from a first-line SCLC trial demonstrating that trilaciclib reduced clinically relevant consequences of chemotherapy-induced myelosuppression versus placebo. Statistically significant results highlighted the benefit of trilaciclib in several prospectively-defined parameters, including: Grade 4 neutropenia, G-CSF usage, and chemotherapy dose reductions and delays. In addition, clinically meaningful data favored trilaciclib versus placebo, including: febrile neutropenia, Grade 3/4 anemia and red blood cell transfusions. Trilaciclib was well tolerated, with no Grade 3/4 trilaciclib-related treatment emergent adverse events reported. In addition to demonstrating myelopreservation benefits across multiple hematopoietic lineages, trilaciclib showed favorable trends versus placebo for duration of response and progression-free survival (PFS). The overall survival data are still immature. The company expects to present additional data from this trial at a medical meeting in the fourth quarter of 2018.
• Completed common stock offering: In March, the company completed an underwritten public offering of 3,910,000 shares of its common stock at a public offering price of $29.50, including 510,000 shares sold pursuant to the full exercise of the underwriters' option to purchase additional shares. G1 received $107.9 million in proceeds from the offering, net of underwriting discounts and commissions, and offering expenses.
• Initiated Phase 1b/2 clinical trial of G1T38 in combination with Tagrisso® for EGFR-mutant non-small cell lung cancer: The company expects to enroll approximately 145 participants in this open-label trial in two parts: a safety, pharmacokinetic and dose-finding portion (Part 1); and a subsequent randomized portion (Part 2). Primary outcome measures include safety and tolerability, identifying a recommended Phase 2 dose and PFS. Secondary outcome measures include assessment of pharmacokinetics, tumor response and overall survival (OS).
• Completed enrollment in Phase 2 trial of trilaciclib in combination with Tecentriq® and chemotherapy: G1 is conducting this placebo-controlled, double-blind Phase 2 trial under a non-exclusive agreement with Genentech to evaluate trilaciclib in combination with the immune checkpoint inhibitor Tecentriq and chemotherapy as a first-line treatment for SCLC patients. The trial was fully enrolled two quarters ahead of schedule. 
• Presented preclinical data on trilaciclib and G1T38 at the American Association for Cancer Research (AACR) Annual Meeting: These preclinical data further support the rationale for the clinical development strategies for both CDK4/6 inhibitors.

Anticipated Upcoming Milestones

• Present preliminary Phase 1b data for G1T38 in combination with Faslodex® in ER+, HER2- breast cancer patients at the 2018 American Society of Clinical Oncology (ASCO) Annual Meeting on June 2, 2018.
• Complete patient enrollment in the Phase 2a trial of trilaciclib in second- / third-line SCLC and the Phase 2 trial of trilaciclib in triple-negative breast cancer in the second quarter of 2018. Preliminary data from these trials, which are evaluating the myelopreservation benefits of trilaciclib for patients undergoing chemotherapy, are expected in the fourth quarter of 2018.
• Initiate a Phase 1/2a trial of G1T48, an oral selective estrogen receptor degrader (SERD), in ER+, HER2- breast cancer patients in the second quarter of 2018.
• Meet with regulatory authorities in the U.S and Europe to discuss the clinical development program for trilaciclib.

First Quarter 2018 Financial Highlights

• Cash Position: Cash, cash equivalents and short-term investments totaled $194.4 million as of March 31, 2018, compared to $103.8 million as of December 31, 2017.
• Operating Expenses: Operating expenses were $20.7 million for the first quarter of 2018, compared to $12.4 million for the first quarter of 2017. GAAP operating expenses include stock-based compensation expense of $1.6 million for the first quarter of 2018, compared to $0.5 million for the first quarter of 2017.
• Research and Development Expenses: Research and development (R&D) expenses for the first quarter of 2018 were $17.3 million, compared to $11.1 million for the first quarter of 2017. The increase in expense was due to an increase in clinical program costs, drug manufacturing costs to support clinical programs and personnel costs due to additional headcount.
• General and Administrative Expenses: General and administrative (G&A) expenses for the first quarter of 2018 were $3.4 million, compared to $1.3 million for the first quarter of 2017. The increase in expense was largely due to an increase in professional fees and personnel-related cost.
• Net Loss: G1 reported a net loss of $20.4 million for the first quarter of 2018, compared to $12.3 million for the first quarter of 2017.

Webcast and Conference Call
The G1 management team will host a webcast and conference call at 4:30 p.m. ET today to provide a corporate and financial update for the first quarter of 2018. The live call may be accessed by dialing 866-763-6020 (domestic) or 210-874-7713 (international) and entering the conference code: 6283059. A live and archived webcast will be available on the Events & Presentations page of the company's website: www.g1therapeutics.com.

About G1 Therapeutics
G1 Therapeutics, Inc., is a clinical-stage biopharmaceutical company focused on the discovery and development of novel therapeutics for the treatment of cancer. G1's two clinical assets, trilaciclib and G1T38, are CDK4/6 inhibitors, a validated and promising class of targets for anti-cancer therapeutics. Trilaciclib and G1T38 have broad therapeutic potential in many forms of cancer and may serve as backbone therapy of multiple combination regimens. In addition, G1 is advancing G1T48, a potential first- / best-in-class oral selective estrogen receptor degrader, or SERD, which is targeted for the treatment of breast cancer.

G1 is based in Research Triangle Park, NC. For additional information, please visit www.g1therapeutics.com and follow us on Twitter @G1Therapeutics.

Forward-Looking Statements
This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Words such as "may," "will," "expect," "plan," "anticipate," "estimate," "intend" and similar expressions (as well as other words or expressions referencing future events, conditions or circumstances) are intended to identify forward-looking statements. Forward-looking statements in this news release include, but are not limited to, the therapeutic potential of trilaciclib, G1T38 and G1T48, and are based on G1 Therapeutics' expectations and assumptions as of the date of this press release. Each of these forward-looking statements involves risks and uncertainties. Factors that may cause G1 Therapeutics' actual results to differ from those expressed or implied in the forward-looking statements in this press release are discussed in G1 Therapeutics' filings with the U.S. Securities and Exchange Commission, including the "Risk Factors" sections contained therein and include, but are not limited to, the inherent uncertainties associated with developing new products or technologies and operating as a development-stage company; G1 Therapeutics' ability to complete clinical trials for, obtain approvals for and commercialize any of its product candidates; G1 Therapeutics' ability to recruit and enroll patients in its studies; competition in the industry in which G1 Therapeutics operates; and market conditions. Except as required by law, G1 Therapeutics assumes no obligation to update any forward-looking statements contained herein to reflect any change in expectations, even as new information becomes available.

Contact:

Jeff Macdonald
Head of Investor and Public Relations
919-213-9835
jmacdonald@g1therapeutics.com