Thought Leaders in Liquid Biopsy: Dr. Howard Scher (Memorial Sloan Kettering Cancer Center)
Dr. Howard Scher is an attending physician and Head of Biomarker Development at Memorial Sloan Kettering (MSK) Cancer Center and Professor of Medicine at the Weill Cornell Medical College.
His research focuses on cellular signaling mechanisms in prostate cancer, and Dr. Scher has been involved in clinical trials for novel cancer therapeutics for many years.
In 2015, Dr. Scher was awarded the American Association for Cancer Research's Team Science Award for his work in the development of enzalutamide, a treatment for prostate cancer. Dr. Scher is currently a member of BLOODPAC’s Executive Committee.
Below, we talk to Dr. Scher about how liquid biopsy and his participation in BLOODPAC have impacted his work as both an oncologist and translational researcher.
How has liquid biopsy impacted how you care for your patients?
The ability to use a blood-based test to assess the progression of my patients’ disease has been huge. I specialize in prostate cancer, which doesn’t typically manifest as tumors that are easy to assess. It’ll infiltrate bone, where it’s hard to tell if the cancerous mass is shrinking or growing. When we need to know how a treatment is working, it’s a huge advantage to be able to do a blood test. And when a drug starts to fail, I need to be able to re-assess the disease and choose the next line of treatment. That can be done by a biopsy, but with metastatic cancer that has spread to different parts of the body, individual regions can be biologically different. So, I may do a biopsy and successfully understand the biology of one spot, but it may not be the same biology in a different spot. With a blood-based liquid biopsy, it’s likely that you can capture a mixture of tumor DNA from different sites. Then we can have a sense of the diversity of the disease within the patient, and that can really help identify the best treatment.
What have you learned as a test developer over the years?
I’ve learned that the real key in biomarker development is to focus on what you are going to do with the result. Why are you looking at this marker, and how will the result improve a patient’s outcome? This is what we call the clinical utility of the test. You need to demonstrate clinical utility in order to have a test approved by the FDA and ultimately covered by insurance. You can have the most interesting test, but unless it’s covered it’s not going get used. Designing clinical trials in order to show clinical utility is time-consuming and costly, and this is where BLOODPAC has been so critical. Having that dialogue with different assay developers to understand the nuance of their tests is important, and having everyone in the same room is much more conducive to understanding. And that understanding goes both ways, because test developers don’t always understand what the best use case for their test might be, but a doctor like me has that expertise. It’s that collaboration that really adds tremendous value to both of our programs. We have a shared goal of improving outcomes.
You participate in BLOODPAC’s Early Detection and Screening working group. How are you working together to move blood-based cancer screening forward?
The group is working on developing validation standards for test performance, including what kinds of metrics to measure as well as how to interpret the results. We’re also getting into the issues of insurance coverage and reimbursement, working closely with FDA on establishing a regulatory path and identifying the evidence needed to show that each test provides value to patients. Having the FDA involved with our group is a dimension that’s very unique, because we can have all perspectives represented at the table.
How will the BLOODPAC collaboration impact test developers, clinicians, and patients?
I think the hardest thing when you’re both a clinician and working on developing therapeutics is that you just don’t have enough time. It’s always a challenge to prioritize. I enjoy seeing patients but there are times when I know I need to work on a clinical trial protocol instead, because that could benefit innumerable patients. Designing clinical trials takes a high degree of expertise, and BLOODPAC helps me with this work. All the member organizations are pooling their knowledge and skills to help design better and more effective clinical trials as a community. Sometimes a laboratory has tested a technique and identified important little things that you would never think about. For example, in the beginning of the liquid biopsy field, we spent a year just figuring out how fast we needed to spin our blood samples in the centrifuge! And what about if you have to ship a sample? How do you make sure it doesn’t degrade? Those are the types of things you have to know, otherwise you jeopardize the test result. And through BLOODPAC, we can pool all this hard-earned knowledge rather than having to figure out every little step in isolation.
