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Prostate Cancer Lab #11: Functional Precision Testing (Tony Letai)

Meeting Summary

Tony Letai, MD, PhD, Professor at Dana Farber Cancer Institute, and President, Society for Functional Precision Medicine, led a discussion on “Functional Precision Medicine for Advanced Cancer”. 

As we look at novel, personalized therapies, how can we have confidence that they will work? Tony wants to increase testing of drugs on patients’ tissue, using the better tools available today, to predict outcomes and guide treatment decisions.

Tony first critiqued the standard process for personalized cancer treatment, which is to take the patient’s tumor, sequence it, and identify a mutation that tells us to use a particular drug. But how often does that happen and the patient gets a response? It’s much less than most of us would think, probably a percentage in the low single digits. There is lots of room for improvement.

He then proposed a different approach to personalize cancer treatments: “functional precision medicine”. You take a drug, you put it on a bunch of tumor cells, and then you use a smart assay to see what happens. This was tried for chemosensitivity about 30 years ago. But there were very few drugs, it was very difficult to culture the tumors in a way that was informative, and we didn’t have good assays. Today, all of those process problems have gotten much better. We have many, many drugs; we have much better ways of culturing tumor cells; and we have much better ways of analyzing them. Tony cited several examples where his assay (“BH3”), which measures how close a cell is to dying (apoptosis), can be used to measure drug effectiveness. In several studies actual patient outcomes were blinded, yet the assay accurately predicted how patients would respond to drugs. The number of such functional testing studies and the number of patients in each study, while providing good evidence, are not as many as we might expect or hope for such a valuable service.

Why isn’t adoption of functional precision testing faster?

One of the biggest challenges is getting fresh tumor tissue on which to run the tests. There is a “Catch 22”: it requires extra effort to do the biopsy to get the tissue, and without evidence that it will accurately predict outcomes, patients and clinicians are loath to expend the extra effort and risk.

One of Tony’s initiatives is to raise awareness of the benefits of functional testing through a society he founded, the Society for Functional Precision Medicine, where experience and successes are shared monthly. He encourages those doing functional tests to accumulate and publish their results, and he also encourages patients, patient advocates, and patient foundations to learn more and be involved.

Laura Kleiman of Reboot Rx and Ally Perlina of CureMatch both agreed that combining functional precision testing with their services is an opportunity worth exploring.


  • Do you have any comments on functional precision testing?
  • The value of functional precision testing seems intuitive, yet it’s not widely practiced. What are the barriers or objections to it?

Upcoming Meetings – Wednesdays at noon Eastern

  • June 15: Payel Chatterjee, Chief Scientist, and Carla Grandori, CEO, SEngine Precision Medicine, on “Organoids”
  • June 22: Selin Kurnaz, PhD, Co-founder and CEO, Massive Bio, on “Finding the Best Clinical Trial”
  • July 13: Panel Discussion: Proteomics and Clinical Decisions – Karin Rodland
  • August 3: Alex Feltus, Professor, Department of Genetics and Biochemistry, and Marc Birtwistle, Associate Professor of Chemical and Biomolecular Engineering and Bioengineering, Clemson, on “Simulation Models to Guide Clinical Decisions”


Meeting Recording

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