Addressing an Unmet Need
Advanced breast cancer today
Despite great efforts to cure cancer, it remains a major cause of death; the annual number of cancer-related deaths worldwide in 2012 is estimated at more than 8.2 million, with over 32 million living with the disease. Breast cancer is the most common form of cancer among women today, affecting approximately 362,000 individuals in the EU and 233,000 in the US each year. Around 1600 new cases are diagnosed every day and 136,000 deaths occur annually in the EU and US alone.
Better tests for evaluating therapeutic efficacy, such as Biovica’s DiviTum® biomarker assay, aim to increase survival and improve quality of life.
“With the goals of therapy focused on improving quality of life and overall survival, the challenge has been finding a test that is safe, non-invasive and reliable to assess response”*
“In the metastatic setting, for those undergoing treatment, it is crucial to determine responders versus non-responder in order to help guide treatment decisions”*
*Lindsey J. Graham et al. “Current Approaches and Challenges in Monitoring Treatment Responses in Breast Cancer” Journal of Cancer, 2014, 5(1), 58-68.
Many patients still do not respond well to treatment
Approximately 80 percent of breast cancers are classified as hormone-sensitive, and endocrine therapy (e.g. aromatase inhibitors, tamoxifen, fulvestrant) can suppress or stop cancer cell proliferation and thus tumor growth. Nevertheless, around 30 percent of all breast cancer patients live with the advanced (metastasized) hormone-sensitive form of the disease in the EU and US. Today, the therapeutic focus is to extend their survival with minimal impact on quality of life and several new innovative drugs, such as palbociclib [Ibrance®], that aim to achieve this goal are now available.
More informative tests are needed
One way to extend survival may well be found in improved biomarkers that provide clinicians with better information about which drugs are likely to have the best effect, and that accurately measure the actual outcome of the prescribed therapy so that they can better optimize the course of treatment. Since many new cancer therapies are very expensive, this ‘predict and monitor’ approach should also result in considerable savings in healthcare costs.
DiviTum® aims to predict and monitor treatment response
Biovica’s DiviTum® is a new and innovative assay intended to predict and monitor treatment response in cancer patients. The patented technology works by measuring the activity of the enzyme thymidine kinase (TK) in blood serum or cell cultures. In normal cells, TK is hardly detectable, but in proliferating cells, levels increase. Since the degree of TK activity is highly associated with cell proliferation, studies suggest that it can act as a suitable biomarker for measuring tumor aggressiveness; its activity is elevated in patients with conditions associated with unregulated cell growth and increased cell proliferation, e.g. advanced breast cancer and other tumors.
Furthermore, changes in TK activity can appear as soon as two to four weeks after starting treatment, which may be several months faster than other evaluation methods. Since advanced breast cancer patients may have a life expectancy measured in months, the speed at which DiviTum® delivers results can have a significant impact on avoiding unnecessary side-effects and possibly prolonging survival. In addition, the test is performed using routine blood samples, which may reduce patient discomfort and save healthcare resources compared with, for example, biopsy procedures.
Analysis of TK activity with DiviTum® can be performed on routine blood samples.
Better monitoring tools are needed for endocrine cancer therapy
Already today, DiviTum® is documented in metastatic breast cancer applications and studies are ongoing to address its potential for monitoring therapy. Determining how well patients respond to treatment means that ineffective therapies could quickly be replaced by more efficacious.
Urgent need to monitor CDK4/6 inhibitor therapy
In ongoing studies, DiviTum® is documented as a potential tool to monitor treatment with CDK4/6 inhibitors such as Pfizer’s palbociclib (Ibrance®). However, about 50% of women respond to palbociclib, and since there is currently no test for CDK4/6 inhibitor efficacy, such drugs are inevitably administered to women who will not benefit from them.
A US study, performed by Dr Cynthia Ma, St Louis, investigated 50 women with clinical stage II or III estrogen receptor positive, HER2 negative breast cancer treated with anastrozole in combination with palbociclib prior to surgery. DiviTum™ was used to measure levels of TK activity in blood samples collected before and after treatment. Results demonstrate a highly significant correlation between the anti-proliferative effect of palbociclib and a reduction in TK activity levels measured by DiviTum™ post two weeks of adding palbociclib and at the time of surgery. (Liu N et al, San Antonio Breast Cancer Symposium 2016)
DiviTum® is currently included in several clinical trials of palbociclib and other CDK4/6-inhibitors in locally-advanced or metastatic hormone-sensitive breast cancer.
High added-value and potential for DiviTum®
Biovica sees great potential for its DiviTum® assay; the test has demonstrated its value as a monitoring tool for the treatment of locally-advanced hormone-sensitive breast cancer by two major therapeutic strategies (endocrine treatment and CDK4/6 inhibitors) as well as a significant correlation to the commonly used tissue proliferation marker Ki67. A marker originating from a simple blood sample holds advantages vs a marker requiring a biopsy.
The long-term market potential of DiviTum® is even greater since many other forms of solid tumors and novel cell cycle regulating therapies exist. The assay is currently being evaluated in numerous studies of various cancer types and treatments.