G1 Therapeutics, Inc. announced the presentation of mature Phase 2 clinical trial results describing the positive impact of trilaciclib in combination with a TROP2 ADC (sacituzumab govitecan; SG) on overall survival (OS) and tolerability compared to SG alone based on historical data from the ASCENT trial. The poster is being presented during the Breast Cancer-Metastatic poster session at the 2024 American Society of Clinical Oncology (ASCO) meeting, held May 31 to June 4, 2024, and will be made available once the poster is presented on June 2, 2024 on the G1 Therapeutics website here. These results support further evaluation of trilaciclib prior to SG or other ADCs and will help determine the design of future pivotal combination trials.

In this trial, trilaciclib significantly reduced the side effect burden - neutropenia and diarrhea in particular - associated with sacituzumab which can meaningfully improve the tolerability of this important therapy. Trilaciclib was administered as a 30-minute IV infusion completed within 4 hours prior to the start of SG treatment on day 1 and day 8 of each 21-day cycle. The primary endpoint was progression-free survival (PFS) per RECIST v1.1. Key secondary endpoints included overall survival (OS), myeloprotection, and safety/tolerability, as well as objective response rate (ORR), clinical benefit rate (CBR; confirmed complete response, partial response, or stable disease lasting 24 weeks from first dose), and duration of response (DOR).

Patient Demographics Enrolled patients (n=30) received a median of 6.0 cycles of treatment, and median follow-up was 15.0 months. The outcomes in this censored population are potentially more comparable to results from the ASCENT study. 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 dependence on the commercial success of COSELA (trilaciclib); the development and commercialization of new drug products is highly competitive; the company's ability to complete clinical trials for, obtain approvals for and commercialize any of its product candidates; 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.

Final Results from the ASCENT study.