When oral navitoclax (ABT-263) was evaluated in an open-label, phase 2 study in adult patients with recurrent and progressive small-cell lung cancer (SCLC) who had received at least 1 prior therapy, this Bcl-2 inhibitor showed only limited activity (Rudin CM, et al. Clin Cancer Res. 2012;18;1-7).
Nevertheless, this study provided evidence that selected biomarkers may have prognostic value in clinical settings; for example, the biomarker plasma pro–gastrin-releasing peptide (pro-GRP) may have value in predicting a patient’s potential to benefit from Bcl-2–directed therapy.
Efficacy end points included response rate, median progression-free survival (PFS), and median overall survival (OS). In addition, concentrations of several exploratory biomarkers, as well as tumor Bcl-2 gene copy numbers, were obtained in these patients and those from a related study.
Baseline concentrations of the biomarkers correlated with median PFS and median OS values. In addition, a strong association was demonstrated between pro-GRP concentration and tumor Bcl-2 copy number.
If confirmed, these study findings may have direct application to the implementation of future navitoclax studies, which the authors believe will focus on combination therapies.
To sign up for our newsletter or print publications, please enter your contact information below.
