Puma Biotechnology presents findings from Phase II study of alisertib

Puma Biotechnology announced the presentation of biomarker findings from a Phase II randomized clinical trial of alisertib alone vs. alisertib + fulvestrant for the treatment of patients with endocrine and CDK4/6 inhibitor resistant, human epidermal growth factor receptor 2-negative, hormone receptor-positive metastatic breast cancer at the 2024 American Society of Clinical Oncology Annual Meeting currently being held in Chicago. The Phase II trial was conducted through the Translational Breast Cancer Research Consortium. Results were published by Tufia Haddad et al. and reported promising clinical activity in both arms and a tolerable safety profile. Somatic mutations from cell-free DNA derived from pre-treatment plasma were identified in ESR1, PIK3CA, PTEN, and AKT1. Patients with PIK3CA mutation experienced decreased progression-free survival while ESR1 mutation did not impact PFS. Circulating tumors cells and methylated tumor fraction percentage were evaluated in pre-treatment and at the end of cycle 1. Lower CTCs in pre-treatment samples were associated with longer PFS. In EOC1 plasma, lower mTF was associated with longer PFS. Additional biomarker analyses are underway.