G1 Clinical Trials

G1 is developing three new oncology therapies that are currently in clinical trials

G1 has three clinical-stage programs, trilaciclib, rintodestrant and lerociclib, that are designed to improve patient outcomes for those affected by cancer. To learn more about our clinical trials, please visit www.clinicaltrials.gov or contact us at clinicalinfo@g1therapeutics.com.

Patients and families should speak to their physician about risks and benefits of a clinical trial and to ask whether a study is right for them.


Trilaciclib is a first-in-class FDA-designated "Breakthrough Therapy" designed to improve outcomes for people with cancer who are treated with chemotherapy. Trilaciclib is currently being studied in small cell lung cancer and triple-negative breast cancer. At this time, we have completed enrollment for our trilaciclib clinical trials in SCLC and TNBC. We have a collaboration with Quantum Leap Healthcare Collaborative to evaluate trilaciclib in a randomized, investigational treatment arm for the ongoing I-SPY 2 TRIAL for neoadjuvant treatment of locally advanced breast cancer (details here). The FDA accepted our New Drug Application (NDA) for trilaciclib for SCLC patients being treated with chemotherapy and granted Priority Review in August 2020 with a Prescription Drug User Fee Act (PDUFA) action date of February 15, 2021. We plan to begin a Phase 3 trial in colorectal cancer in the fourth quarter of 2020.


Rintodestrant is a potential best-in-class oral selective estrogen receptor degrader (SERD) being studied as monotherapy or in combination with other targeted therapies to treat estrogen receptor-positive (ER+) breast cancer. We are currently recruiting women with ER+, HER2-negative advanced breast cancer for a Phase 1/2 trial assessing the safety, tolerability, pharmacokinetics, and preliminary antitumor activity of rintodestrant. In 2020, we initiated an additional arm of our ongoing Phase 1/2a trial to evaluate the combination regimen of rintodestrant and the CDK4/6 inhibitor Ibrance® (palbociclib). For more information, please visit www.clinicaltrials.gov (Identifier: NCT03455270).


Lerociclib is a differentiated oral CDK4/6 inhibitor being developed for use in combination with other targeted therapies in types of breast and lung cancer. It is currently being studied in estrogen receptor-positive, HER2-negative (ER+, HER2-) breast cancer and epidermal growth factor receptor mutation (EGFRm) non-small cell lung cancer. At this time, we have completed enrollment and are not recruiting patients for our ongoing trials. 

We entered into separate, exclusive agreements with EQRx (rights for U.S., Europe, Japan, and all markets outside Asia-Pacific) and Genor (rights for Asia-Pacific, excluding Japan) for the development and commercialization of lerociclib in all indications.