Trilaciclib fails to extend OS in metastatic triple-negative breast cancer
The addition of trilaciclib to chemotherapy did not improve OS among patients with metastatic triple-negative breast cancer, according to the agent’s manufacturer.
Trilaciclib (Cosela, G1 Therapeutics), a cyclin dependent kinase 4/6 inhibitor, is approved in the United States to reduce frequency of chemotherapy-related bone marrow suppression among patients with extensive-stage small cell lung cancer.
The randomized phase 3 PRESERVE 2 trial included 187 patients with metastatic triple-negative breast cancer.
Researchers assessed the efficacy and safety of trilaciclib prior to gemcitabine/carboplatin chemotherapy.
Results showed no OS benefit with trilaciclib plus chemotherapy vs. chemotherapy alone (median, 17.4 months vs. 17.8 months; HR = 0.91).
Investigators observed numerical improvement in OS with trilaciclib among patients with PD-L1-positive and PD-L1-negative disease; however, neither achieved statistical significance.
Trilaciclib exhibited a safety profile consistent with that observed in prior trials. Researchers observed no new safety signals.
“The unexpected results from PRESERVE 2 underscore the challenge of developing new therapies for triple-negative breast cancer,” Jack Bailey, CEO of G1 Therapeutics, said in a company press release. “We are disappointed that this trial did not deliver the benefit that we anticipated to people living with [triple-negative breast cancer]. We will now further our focus on both accelerating and expanding the growth of the [extensive-stage small cell lung cancer] business to achieve anticipated company profitability in the second half of 2025 and evaluating other myeloprotection uses for trilaciclib.”
Complete data from PRESERVE 2 will be presented at a medical conference.