Tom Willis, CEO of Arima Genomics since June 2025, is the featured guest of the Illumina Ventures Spotlight Series for October. He brings 20 years of genomics entrepreneurship, including a decade as a Venture Partner at Illumina Ventures.

In this conversation, Tom describes Arima’s academic origins and its pioneering technology, which preserves the spatial organization of DNA within the cell nucleus, unlike traditional sequencing methods. In this 3-minute read, Willis shares how Arima’s approach unlocks previously inaccessible information, setting it apart in the precision oncology landscape.

What is your origin story? How was Arima Genomics created?

Tom Willis:

Arima’s origin story is quite familiar to me as a guy who started his entrepreneurial career as a spin-out from an academic lab. Arima started in much the same way. The founder was working on technology in the lab he thought had broad applicability and spun out a tools company. It was all about unlocking the power of the information that was contained within the structure of DNA packed inside the nucleus of a cell. So, instead of starting a DNA sequencing protocol by taking the DNA out of a nucleus and turning it into a soup of a billion puzzle pieces, he was interested in how we could capture the information contained within the nucleus and the way that DNA was packed inside a cell. Turns out, there were a lot of broad applications in biology, and they set up a company which enabled researchers to explore that space with kits and services. That company ultimately had quite a good run. There are 1500 publications based on that technology in the literature. But what really changed is they found the killer app for this technology, and that is in cancer biology, elucidating the signals that are in tumor cells that are encoded within those structural changes in the nucleic DNA.

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

Tom Willis:

If you think about cancer and the treatment of cancer, it really is the signature achievement for personalized therapy and the approach of precision medicine as applied to a human disease. The biology of cancer has been elucidated by NGS technologies and the molecular exploration of cancer. The translation of that information into drug development, developing drugs based on molecular signatures, and the success and innovation in that area has allowed patients to access innovative therapies based on the molecular profile of their tumor.

Yet, about half the patients being treated for cancer today are not treated according to the molecular profile of their tumor, so we're still missing half the signal. Arima aims to close that gap and allow many more patients to be treated based on the molecular profile of their cancer.

There are molecular alterations in tumors for which effective therapies exist today, but inefficiencies in the testing paradigms mean those therapies are not reaching all patients. We think there are about 30,000 patients for whom we can find actionable alterations that are being missed by the current standard of care. Arima's technology is very powerful at finding large-scale structural changes in DNA, which is exactly where current approaches are less effective. We can combine structural variation with mutation detection to do a much more comprehensive analysis of tumor samples and direct therapy.

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

Tom Willis:

Our superpower is in our technology. A lot of people imagine DNA inside cells by thinking of pictures of chromosomes, which are separated in neat ways. In reality, inside most cells, DNA is packed into a really dense spaghetti ball. This structure contains all the chromosomes packed together.

In typical next generation sequencing workflows, we start by taking that elegant structure and turning it into a billion puzzle pieces. We break up the puzzle, losing all the information about how it was originally assembled. The sequencer is amazing at figuring out the sequences of those individual pieces.

However, in cancer applications, we want to understand how the chromosomes were structured and whether the cancer cell has created abnormal structures. To do that, we need to know what the puzzle looked like at the start. Our technology preserves the spatial information within the nucleus about where individual sequences are in relation to each other. We use a biochemical method to join together sequences that were next to each other within that complex structure. By the time we reduce this to a billion puzzle pieces, we have retained index information about which pieces of DNA were next to others. This allows us to completely reconstruct the structure of the starting material. As a result, we can find translocations and also loops within a chromosome that might have biological activity.

What type of opportunities are available by being part of the Illumina Ventures portfolio?

Tom Willis:

There's no VC fund richer in a portfolio of diagnostics companies that are leveraging NGS than Illumina Ventures. All the partners here have been involved in those companies successfully. So, the KOL networks, the key employees that are in the network of Illumina Ventures, the entrepreneurs that are building companies in the portfolio that we can access, all of that makes this just a no-brainer for the best possible investor in a company like this. So obviously, I've been on both sides of this, and being able to benefit from it is quite a nice thing.