Trilaciclib appeared associated with reduced chemotherapy-induced myelosuppression and was well tolerated among patients undergoing first-line therapy for extensive-stage small cell lung cancer, according to results from a double-blind, placebo-controlled phase 2 trial.
Trilaciclib (G1 Therapeutics) is a short-acting CDK4/6 inhibitor that preserves hematopoietic stem cells and enhances immune system function — myelopreservation — during chemotherapy.
“The data from this trial showed clear evidence that trilaciclib preserved bone marrow and immune system function from the damaging effects of chemotherapy,” Raj Malik, MD, chief medical officer and senior vice president of research and development at G1 Therapeutics, said in a company-issued press release. “Moreover, the myelopreservation effects demonstrated by trilaciclib improved patient outcomes. Chemotherapy continues to be a cornerstone of cancer treatment, and trilaciclib has the potential to benefit many of these patients.”The researchers randomly assigned 77 treatment-naive patients with extensive-stage small-cell lung cancer 1:1 to IV trilaciclib or placebo administered before each dose of etoposide and carboplatin chemotherapy.
Trilaciclib appeared associated with reduced clinically relevant consequences of chemotherapy-induced myelosuppression, including:
67.5% reduction among patients with grade 3 or grade 4 hematologic treatment-emergent adverse events;
51.3% reduction among patients with grade 3 or grade 4 neutropenia;
83.8% reduction among patients with granulocyte colony-stimulating factors administration; and
77.5% reduction among patients with chemotherapy dose reductions.
Treatment with trilaciclib also reduced grade 3 anemia, red blood cell transfusions and grade 3 thrombocytopenia compared with placebo.
Trilaciclib appeared associated with trends toward improved ORR (66.7% vs. 62.2%), median duration of response (5.7 months vs. 4.3 months) and median PFS (6.2 months vs. 5 months; HR = 0.6; P = .06), but these data had not yet matured.
Additionally, trilaciclib appeared well tolerated.
“The strength of this dataset provides us with a solid foundation to advance the development of trilaciclib and its ultimate commercialization,” Mark Velleca, MD, PhD, G1 Therapeutics CEO, said in the release. “As shown by our nonexclusive collaboration with Genentech, there is significant interest in combining trilaciclib with checkpoint inhibitor/chemotherapy regimens. We believe that trilaciclib has the potential to become backbone therapy for multiple chemotherapeutic regimens across a variety of cancer types, delivering significant benefits to patients and creating a substantial long-term commercial opportunity.”
The company plans to share data with regulatory authorities this year.