Uppsala, Sweden, May 11, 2020. The scientific journals British Journal of Cancer, a Nature journal, and Biomarkers in Medicine have published articles on DiviTum® results and TK activity as a biomarker for evaluating efficacy of CDK4/6 inhibitors. The editorials conclude that DiviTum data has the potential to become a standard prognostic biomarker and tool for early recognition of treatment resistance in metastatic breast cancer.
DiviTum® measures thymidine kinase (TK) activity, an established marker of cancer cell proliferation. The authors state that identification of new predictive and prognostic biomarkers in breast cancer has proven to be a frustratingly elusive goal for many researchers to date. However, DiviTum has been shown to be both prognostic for progressive disease and overall survival and with the ability to identify early resistance to treatment in patients receiving endocrine therapy with or without CDK4/6 inhibitors in metastatic breast cancer. The authors conclude that TK seems an intuitive choice of biomarker to monitor the efficacy of CDK4/6 inhibitors.
“DiviTum is the pioneering technology to document TK1a as a breast cancer biomarker to estimate prognosis and early recognition of treatment resistance that can be clinically very useful,” said Dr. Luca Malorni, Prato Hospital, Italy, co-author of the articles.
The authors conclude that further validation of TK1 as a biomarker in the setting of CDK4/6 inhibition is required and mention that further prospective validation is currently underway in a number of ongoing CDK4/6 inhibitor-based trials, including the Phase II biomarker discovery clinical trial PYTHIA (Palbociclib in Molecularly Characterized ER-positive/HER2-negative Metastatic Breast Cancer) and BioItaLEE, a Phase IIIb study in postmenopausal women receiving letrozole plus ribociclib as ﬁrst-line management of metastatic disease.
“The broad applicability of TK1 as a marker of prognosis and early resistance to a uniform regimen may represent an appealing clinical and research tool that can be generalized to a large population of patients,” said Dr. Amelia McCartney, Prato Hospital, Italy, co-author of the articles.
Biomark.Med. (Epub ahead of print) 10.2217/bmm-2020-0072