Expert insight

Smart Testing in Personalised Healthcare – ctDNA is Set to Change the Companion Diagnostic Landscape

10 September 2014

In the pursuit of truly personalised healthcare, AstraZeneca has entered into partnerships with Roche and QIAGEN for the clinical development of novel diagnostic tests based on circulating tumour DNA (ctDNA). These tests will move us to the next generation of companion diagnostics by allowing detection of recognised tumour mutations based on accurate analysis of minute quantities of tumour DNA found circulating in cancer patients’ blood.

AstraZeneca is a pioneer in the cutting edge technology of ctDNA, which uses “smart tests” that can pick out specific signals from a background of normal DNA noise. I have been involved with this exciting development for many years, working with technical experts who have pushed the boundaries of science to take ctDNA testing from a highly exploratory science to a robust technology that can be used in clinical practice for our companion diagnostic projects.

Our first research programme in ctDNA started with a clinical fellowship in 2006. In particular, our experience with EGFR testing in non-small cell lung cancer provided the clinical setting in which to correlate ctDNA to tumour samples. We recognised the potential that ctDNA technology has to improve diagnosis and treatment in this type of cancer, where many patients have limited or no tumour samples for testing.

From my perspective this technology is most exciting because it makes it possible for innovative drugs to become available to patients where no suitable tumour sample is available. Blood can be taken at a medical centre quickly and easily, since it doesn’t require hospitalisation or the use of an expensive diagnostic imaging suite.

Regulators have also been quick to recognise the promise of these novel techniques for patients, and have worked actively with the diagnostics and pharma industries. Of course it is the priority of the regulators to protect patients, but I’ve seen that the authorities were keen to review data and discuss what evidence would be needed to approve companion diagnostics based on ctDNA.

As with most scientific developments, we often forget how many challenges were involved. I am very proud of the tenacity of our scientists; the years of work that went into selecting the best techniques and preparation methods for ctDNA.  To start with, we were even unsure if oncologists would trust test data from blood, when they were so used to dealing with tissue samples. All these obstacles have been overcome.

In the future, I would like to see these tests developed so that they could monitor the progression of cancer and even detect if cancers return. Currently, companion diagnostic testing is done using an individual sample based on the assumption that tumours are static. In reality, however, cancers evolve over time in response to treatment. Some experts have speculated that a more sensitive ctDNA technology could be developed to monitor cancer as it changes its molecular nature, allowing us to prescribe the right medicines throughout the course of therapy. This would represent a real clinical advance and confirm ctDNA as a cornerstone of personalised healthcare.

These partnerships on ctDNA are a significant step in Personalised Healthcare scientific innovation. They move us one step closer to achieving our bold ambition of transforming patients’ lives through personalised healthcare by ensuring that innovative treatments are matched to those patients who will benefit most.

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  • Ruth March