Honey Reddi on Liquid Biopsies and her Predictions for Precision Medicine
Posted 29th December 2017 by Jane Williams
Honey Reddi, Clinical Laboratory Director at the Jackson Laboratory spoke at the 4th Global Precision Medicine and Biomarkers Leader Summit. She gives us an insight on liquid biopsies in the clinic and the effectiveness of current treatment.
Tell us a bit about the Jackson Lab
The Jackson Laboratory is a non-profit academic organisation which has three sites; their headquarters in Maine, a centre for human genetics in Connecticut and JAX mice in California. When people hear about the Jackson Labs, they often think only about JAX mice because they’ve been the pioneering organisation for providing mouse models for research for the last 100 years. However, my work in Connecticut focuses on clinical genetics.
The vision of JAX is the translation of innovation to practice and towards that end; in the clinical lab we take technology applications and tools from the researchers at JAX and do what is needed from a regulatory perspective to make them clinically available to physicians. We also work with Biotech and Pharma to provide custom assays as well as develop specific clinical assays addressing the unmet need of the patient.
What are your thoughts on liquid biopsies being the next hot topic?
They are indeed a hot topic, but I think true clinical utility is yet to be reached. From the perspective of patient follow-up where you are testing their primary tumour biopsy, you want to be able to monitor recurrence, resistance and their response to therapy.
There are two ways you can do this. You can take the same panel that you run on the biopsy and run it on the liquid biopsy but the limitation here is the amount of DNA you get from the plasma, which is a combination of normal and tumour DNA versus how much you can potentially get from a tumour biopsy. There are labs that run big panels on the liquid biopsy, but it is probably not the best way to go about it. That is why we designed a hotspot panel as we did not want to end up with variants of uncertain significance.
We want to be able to have those actionable variants in the sense of predicting sensitivity or resistance to certain drugs. We also want to be able to monitor specific mutations throughout the course of the patient’s treatment and management.
We also need to look at the percentage of mutations that are missing detection. With our hotspot panel, if you don’t follow exactly what we found on the tumour biopsy, it’s not present on our panel and it’s one of those rare mutations, then realistically using our panel doesn’t make sense, in which case, it may be best to specifically follow that one mutation identified in the tumour biopsy. The downside of that is you’re not identifying new mutations that could have arisen. The commercial industry always believes more data is better, but I believe this should change, keeping in mind precision medicine that is actionable.
What are your predictions for the future?
I think we should expect to see more partnerships for companion diagnostics. However, the impact of the drugs in terms of the mutations of the patient must be considered. Clearly, companion diagnostics is one way that you can see the trend moving towards. The question is how successful are they going to be in terms of the bigger picture for the patient?
Right now, liquid biopsies are being used more to monitor systems and minimal residue of disease and recurrence. I doubt we are going to see it being used for diagnosis in the next couple of years as there is still a lot of work that needs to be done. This is because for diagnosis, to be able to do a liquid biopsy, you need a certain amount of DNA with mutations in the plasma.We are assuming that the tumour sheds enough to be able to detect mutations, but we cannot be absolutely sure, especially since it also depends on the tumour heterogeneity, which side of the tumour sheds and what is found must also be considered. I don’t think for diagnostics it is going to be that effective immediately.
Honey Reddi is Clinical Laboratory Director at the Jackson Laboratory. Her research focuses on liquid biopsies in the clinic. Find out more about the Jackson Laboratory here
If you enjoyed this blog, you might also enjoy ‘Considerations for the Development of a Liquid Biopsy Assay for Cancer’
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