GTHX G1 Therapeutics Inc

G1 Therapeutics, Inc. (Nasdaq: GTHX), a commercial-stage oncology company, today presented results from analyses evaluating the immune effects of trilaciclib in patients with extensive-stage small cell lung cancer (ES-SCLC) following two Phase 2 clinical trials. Results of the analyses, presented at the American Society of Clinical Oncology (ASCO) annual virtual meeting, demonstrated that patients receiving COSELA prior to chemotherapy had greater peripheral T-cell clonal expansion than patients receiving placebo. The goal of clonal expansion is to amplify the number of specific lymphocytes (B-cells and T-cells) to enable the body to have sufficient numbers of antigen-specific lymphocytes to mount an effective immune response. The eAbstract is available in the scientific publications section of G1’s website. 

“Mounting a robust immune response against a tumor necessitates sufficient numbers of antigen-specific T-cells to recognize and combat the cancer cells,” said Raj Malik, Chief Medical Officer at G1 Therapeutics. “In our genomic analysis of tumor cells and peripheral blood cells, we found that administration of COSELA prior to chemotherapy resulted in an expansion of newly-detected peripheral T-cell clones. This clonal expansion was associated with clinical response and is indicative of anti-tumor immune enhancement. We are encouraged by these preliminary results and look forward to clarifying the potential immune enhancing effects of COSELA in the tumor microenvironment.”

The genomic analysis of DNA followed two Phase 2 trials in patients with ES-SCLC. Researchers subsequently evaluated patient tumor cells and peripheral blood to quantify the abundance of specific T-cell receptors at baseline and after treatment with either COSELA or placebo prior to chemotherapy (either first-line etoposide plus carboplatin (E/C) or E/C plus atezolizumab (E/C/A)). The results of the analysis presented in the eAbstract include the following:

• In both studies, peripheral T-cell clonal expansion was greater among patients receiving COSELA versus patients receiving placebo.
• Among patients receiving E/C:
  • Patients receiving COSELA who demonstrated an antitumor response had significantly more peripheral clonal expansion than placebo responders (P=0.04) and a greater number of tumor-associated expanded clones (P=0.03).
  • COSELA responders had more newly detected expanded peripheral clones compared with placebo responders (P=0.06) and COSELA non-responders (P=0.02).
  • Increased clonal expansion in trilaciclib responders was more evident after two cycles of E/C versus four, suggesting that trilaciclib results in a rapid T-cell response.
• Among patients receiving E/C/A:
  • Patients receiving COSELA who demonstrated an antitumor response had significantly more peripheral clonal expansion than placebo responders (P=0.002) and COSELA non-responders (P=0.016), and a greater number of tumor-associated expanded clones.
  • COSELA responders also had more newly expanded peripheral clones compared with placebo responders (P=0.003) and COSELA non-responders (P=0.02).
  • There was no increase in tumor-associated expanded clones among trilaciclib responders compared to placebo responders, possibly due to the time point (after four cycles) at which clonal expansion was assessed.

G1 Therapeutics also presented a poster at ASCO describing the design of PRESERVE 2, the Company’s ongoing Phase 3, randomized, double-blind trial of COSELA in patients with locally advanced unresectable or metastatic triple-negative breast cancer. (poster)

About Small Cell Lung Cancer

In the United States, approximately 30,000 small cell lung cancer patients are treated annually. SCLC, one of the two main types of lung cancer, accounts for about 10% to 15% of all lung cancers. SCLC is an aggressive disease and tends to grow and spread faster than NSCLC. It is usually asymptomatic; once symptoms do appear, it often indicates that the cancer has spread to other parts of the body. About 70% of people with SCLC will have cancer that has metastasized at the time they are diagnosed. The severity of symptoms usually increases with increased cancer growth and spread. From the time of diagnosis, the general 5-year survival rate for people with SCLC is 6%. The five-year survival rates for limited-stage (the cancer is confined to one side of the chest) SCLC is 12% to 15%, and for extensive stage (cancer has spread to the other lung and beyond), survival rates are less than 2%. Chemotherapy is the most common treatment for ES-SCLC.

About COSELA™ (trilaciclib) for Injection

COSELA (trilaciclib) was approved by the U.S. Food and Drug Administration on February 12, 2021.

IndicationCOSELA™ (trilaciclib) is indicated to decrease the incidence of chemotherapy-induced myelosuppression in adult patients when administered prior to a platinum/etoposide-containing regimen or topotecan-containing regimen for extensive-stage small cell lung cancer.

Important Safety InformationCOSELA is contraindicated in patients with a history of serious hypersensitivity reactions to trilaciclib.

Warnings and precautions include injection-site reactions (including phlebitis and thrombophlebitis), acute drug hypersensitivity reactions, interstitial lung disease (pneumonitis), and embryo-fetal toxicity.

The most common adverse reactions (>10%) were fatigue, hypocalcemia, hypokalemia, hypophosphatemia, aspartate aminotransferase increased, headache, and pneumonia.

This information is not comprehensive. Please click here for full Prescribing Information. https://www.g1therapeutics.com/cosela/pi/   

To report suspected adverse reactions, contact G1 Therapeutics at 1-800-790-G1TX or call FDA at 1-800-FDA-1088 or visit www.fda.gov/medwatch.

About G1 Therapeutics

G1 Therapeutics, Inc. is a commercial-stage biopharmaceutical company focused on the development and commercialization of next generation therapies that improve the lives of those affected by cancer, including the Company’s first commercial product, COSELA™ (trilaciclib). G1 has a deep clinical pipeline and is executing a tumor-agnostic development plan evaluating COSELA in a variety of solid tumors, including colorectal, breast, lung, and bladder cancers. G1 Therapeutics is based in Research Triangle Park, N.C. For additional information, please visit www.g1therapeutics.com and follow us on Twitter @G1Therapeutics.

G1 Therapeutics™ and the G1 Therapeutics logo and COSELA™ and the COSELA logo are trademarks of G1 Therapeutics, Inc.

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 press release include, but are not limited to, those relating to expectations for the commercial launch of COSELA (trilaciclib), the therapeutic potential of COSELA (trilaciclib), and COSELA’s (trilaciclib) possibility to realize the economic impact in the US market presented in the scientific analyses described above, and COSELA (trilaciclib) may fail to achieve the degree of market acceptance for commercial success, are based on the company’s 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 the company’s actual results to differ from those expressed or implied in the forward-looking statements in this press release are discussed in the company’s filings with the U.S. Securities and Exchange Commission, including the "Risk Factors" sections contained therein and include, but are not limited to, the company’s ability to complete a successful commercial launch for COSELA (trilaciclib); the company’s ability to complete clinical trials for, obtain approvals for and commercialize any of its product candidates other than COSELA (trilaciclib); the company’s initial success in ongoing clinical trials may not be indicative of results obtained when these trials are completed or in later stage trials; the inherent uncertainties associated with developing new products or technologies and operating as a commercial-stage company; and market conditions. Except as required by law, the company assumes no obligation to update any forward-looking statements contained herein to reflect any change in expectations, even as new information becomes available.

G1 Therapeutics Contact:

Will Roberts

Vice President, Investor Relations & Corporate Communications

919-907-1944

wroberts@g1therapeutics.com