This month we turn the spotlight on DELFI Diagnostics’ CEO Susan Tousi. She spent 12 years at Illumina as a strategic commercial leader, including 9 years as SVP of Product Development and Chief Product Officer running all of Product Development, and 3 years as Chief Commercial Officer. In January 2024 Tousi was hired to succeed DELFI founder Victor Velculescu, M.D., Ph.D.

In this 3-minute read Tousi discusses the potential impact DELFI’s cancer detection tests can have on healthcare and the unique population it could serve.

 

What is your origin story? How did DELFI Diagnostics start?  

Susan Tousi: 

“It was really a discovery by Victor Velculescu at Johns Hopkins who is a leading scientist in the field of cancer genomics. It became clear to him that the way to attack cancer was to find and detect it early where patients had more options for treatment and where outcomes were much better. He was studying the cancer genome and realized that there were patterns in the cell-free DNA that would underlie the presence of cancer. The free-floating cell-free DNA that came from cancer tumors, as they were shedding, were very different than those from healthy cells. He discovered if you were looking across the genome and applied machine learning to bring out the signal of these features relative to the noise in the background of healthy cell-free DNA, you could get a very high signal-to-noise ratio for detection of cancer.

And in fact, you could do this through whole genome sequencing, and you didn't have to do deep genome sequencing, you could do a low pass. And that low-pass sequencing led to the approach that DELFI has taken, which is a whole-genome, fragmentomics-based method that provides a high application of machine learning and AI, enabling cancer to be screened at the earliest stages with high sensitivity, but at a disruptive cost structure.”

 

What type of impact do you believe DELFI will have on healthcare?

Susan Tousi: 

“Lung cancer for example impacts 15 million people in the U.S., and the test that is the standard of care today for detecting lung cancer is low-dose CT scanning. But unfortunately, of those 15 million people who are eligible for low-dose CT scanning, less than 6% get it done. Lung cancer is typically found at the late stage with a poor survival prognosis. But when detected early, the 10-year survival rate is 73% so this is a cancer that can be addressed.  What is most compelling about lung cancer is that it typically impacts populations who are the most underserved and hardest to reach. DELFI’s tests, at very low cost, can uniquely address a population that wouldn't otherwise have access. And we think that this can be done globally. Our test is easy to deploy, it's essentially the easiest assay you can do, it's low-pass genome sequencing. And as a result, we feel that we're going to address a huge unmet need in the population in that we have a test that's designed for everyone and not just for the few who would have access.”

 

How does DELFI stand out from the competition? In other words, what is your superpower?

Susan Tousi:

“We have so many opportunities. I mentioned the large unmet need in lung cancer. But we've shown evidence in liver cancer and ovarian cancer. We've shown a multi-cancer application for our core technology, seven of the deadliest cancers. Plus, we have a fantastic opportunity for monitoring therapy response. So, we have this incredible runway of new innovations. And if you look at the number of publications and applications that keep being produced off this core whole-genome fragmentomics platform it's exciting. 

I think the ability to detect cancer early, do that at scale, and do that through massive innovation, I jump out of bed in the morning excited about the impact that we can have for patients. It's certainly what brought me to DELFI.”

 

What type of opportunities does the Illumina Ventures investment create for DELFI?  

Susan Tousi:

“I think that Illumina Ventures uniquely understands the opportunity in genomics, multiomics and the applications of that. I think that they uniquely understand diagnostics, molecular diagnostics and the impact that it's going to have on society, and the impact that it can have in generating value. They also bring to the table an incredible portfolio of companies and there are many synergies and partnerships that can be developed there. I think their expertise and advice has been absolutely game changing. Having the benefit of their network is incredibly important. We're thrilled to be partnered with Illumina Ventures, they've been a great asset to us.”