PRESERVE 2 Trial of Trilaciclib Completes Enrollment of Patients With Metastatic TNBC

The PRESERVE 2 trial evaluating trilaciclib in patients with metastatic breast cancer has finished enrolling patients. Results from the interim analysis of the trial is expected in the second half of 2023.

Enrollment has been completed in the phase 3 PRESERVE 2 trial (NCT04799249) of trilaciclib (Cosela) in patients with metastatic triple negative breast cancer (TNBC) receiving chemotherapy, according to G1 Therapeutics, Inc.1

“PRESERVE 2 is exciting as it is evaluating trilaciclib in metastatic TNBC to build on the robust survival benefit observed in the phase 2 program. Completion of enrollment is an important milestone for G1 and the patients we seek to treat, and we look forward to the interim analysis, which is expected to occur in the second half of 2023. This is a registrational trial for which we have been granted Fast Track designation by the FDA and if the results are positive, we will work closely with the FDA to expedite our regulatory filing for approval in this indication,” said Raj Malik, MD, chief medical officer of GI Therapeutics, Inc, in the press release.

The global multicenter, randomized, double-blind, pivotal, phase 3 PRESERVE-2 trial is examining the safety and efficacy of trilaciclib compared with placebo administered prior to gemcitabine and carboplatin in 187 patients with metastatic TNBC.2

There will be 2 separate cohorts evaluated in the trial but both cohorts will follow the same general study conduct and design and have similar primary and key secondary end points. In cohort 1, patients receiving first-line therapy, regardless of PD-L1 status, who are programmed PD-1/PD-L1 inhibitor therapy naïve will be evaluated. Cohort 2 will evaluate patients who are PD-L1 positive and receiving second-line therapy following prior PD-1/PD-L1 inhibitor therapy in the locally advanced unresectable/metastatic setting.

The regimen consists of trilaciclib, gemcitabine, and carboplatin administered intravenously on days 1 and 8 of each 21-day cycle. Treatment is administered until disease progression.

Enrollment is open to patients aged 18 years and older with evaluable locally advanced unresectable or metastatic TNBC. Requirements for the trial include having documentation of TNBC, available archival tumor tissue, an ECOG performance status of 0 or 1, and adequate organ function as demonstrated by normal laboratory values. Radiation therapy for metastatic disease is also permitted.

The primary end point is the effect of trilaciclib vs placebo on overall survival (OS) in patients receiving first-line gemcitabine and carboplatin. The secondary end points of the study include quality-of-life and effects on chemotherapy-induced fatigue, myeloprotective effects, and progression-free survival.

Results from the interim OS analysis which will be conducted by the data monitoring committee of the trial are expected to be announced in the second half of 2023. If the trial meets the interim analysis stopping rule, it will end, and the company will report the topline results. If it does not, the trial will continue to the final analysis.

  1. Completes enrollment in global multi-center phase 3 clinical trial of trilaciclib in patients with metastatic triple negative breast cancer (TNBC). News release. G1 Therapeutics, Inc. October 10, 2022. Accessed October 12, 2022.
  2. Trilaciclib, a CDK 4/6 inhibitor, in patients receiving gemcitabine and carboplatin for metastatic triple-negative breast cancer (TNBC) (PRESERVE 2). Updated August 2, 2022. Accessed October 12, 2022.