The Sixth Annual Next Generation Dx Summit (NGDx) was the first conference I have attended in quite a few years. I was drawn to it by its emphasis on new research areas in clinical assay development and how the biomedical industry can bring these potentially life-saving diagnostics to market to fight diseases and benefit personalized medicine (PM). I decided to focus on two tracks for the conference. Companion Diagnostics: Strategy & Partnerships appealed to my personalized medicine interests and Clinical Application of Cell-Free DNA allowed me to see new research on a specific application of a potentially game-changing diagnostic approach.
Admittedly, the Companion Diagnostics: Strategy & Partnerships track was rather weak with most of the talks asking a very similar question: Are clinical diagnostics (CDx) ready to help personalized medicine? The answer was typically a long: it depends. However, there were two excellent presentations that really hit it home in this track that tried to really answer that question.
It’s Personalized Medicine, not Personalized Cancer Medicine
Eric Lai from Takeda Pharmaceuticals gave a great keynote presentation. He indicated that PM and CDx will be essential for market success in pharmaceutical drug development. No controversy there.. However, he broke away from the dominant conference theme with his assertion that PM won’t be successful unless we start applying it to diseases besides cancer. I note this as a critical statement in retrospect because my experiences at this conference definitely indicated that cancer was what was on people’s minds.
That’s all great, but how much?
The next great talk in this track was about the health economics surrounding CDx and PM from Nick Poulios from Roche Molecular Systems. Poulios shows that there are a lot of “players” in this area and they all have to play nicely in order for the economics of PM to work and be successful. As he states, you have a value matrix of customers and PM tools must not only target patients, but also those who will be supplying the CDx data and insurance companies that will be providing reimbursement for the tests. This is an important point as up to this point, I have always thought of patients as the target for PM, not the others involved in the process.
Cell-Free DNA as a Prenatal Diagnostic
The Clinical Application of Cell-Free DNA track was a highly specific track exploring the possibilities of a somewhat new area of research. Sequencing cell-free DNA has already been introduced into the diagnostics world but in an indirect way.
Brigitte Faas from Radboud University Nijmegen Medical Center gave a nice summary of the current CDx offerings in the world of prenatal disease diagnosis. Companies like Natera, Sequenom, Arinosa and Verinata all offer Dx tests that can determine chromosomal abnormalities from sequencing fetal DNA found in a maternal blood sample. Right now, those tests are limited to identifying prenatal conditions like Trisomy 13, Trisomy 18 and Trisomy 21 and sex chromosome abnormalities but Faas indicated that newer tests are arriving soon that will be able to identify smaller, more specific deletions that are responsible for diseases like Jacobsen syndrome and Langer-Giedion syndrome.
Personally, I have nothing but wonderful things to say about these tests as my wife was offered the Verinata test when she was pregnant with our second child almost two years ago. Before these tests, parents relied on a screening test that might put you in a high-risk category. At that point, you would have to decide if you wanted to have a relatively risky procedure performed like an amniocentesis or chorionic villus sampling to provide definitive information. With the new fetal DNA sequencing tests, none of these are necessary. And, think about this: you can find out the sex of the baby even earlier!
Can Cell-Free DNA Work as a Cancer Dx?
Scott Kopetz from the MD Anderson Cancer Center gave what I think was the best overall presentation about how cell-free DNA could be used as a CDx in the battle against cancers. Kopetz points out that not all cancers start and end the same. Rather, researchers are now finding that there is a great amount of tumor heterogeneity at the DNA-level within the same patient. These differences can arise from mutations to critical genes and resistance to targeted therapies while the tumors grow and metastasize.
The important thing to take home is when a doctor takes a biopsy of a tumor, they are not really getting the whole picture. Kopetz shows how using circulating tumor DNA (ctDNA) from the blood (or other fluids like urine) can be used to get a highly sensitive picture of a patient’s current oncological profile. Concentrations of ctDNA correlate nicely with the amount of tumor in a patient’s body and it is also possible to see ctDNA in cases where there may be no obvious other signs of cancer.
Where he sees the most promise is using measurements of patients’ ctDNA to see how they are responding to a particular treatment in a non-invasive approach. If ctDNA concentrations are going down during the course of a drug treatment, an oncologist would be more inclined to keep on the same treatment program. However, if there was an increase in ctDNA, the current treatment plan is probably not working.
The conference ties in nicely with Will FitzHugh’s blogs posts about the Map of Biomedicine which gives excellent details on how to find your way through the labyrinth of processes involved in drug development, clinical diagnostics and FDA approval. I encourage you to take a look!
Image credit: By Kenny Louie from Vancouver, Canada (Hah! Uploaded by russavia) [CC-BY-2.0 (http://creativecommons.org/licenses/by/2.0)], via Wikimedia Commons