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How Falcons’ Fortunes winner plans to stop colorectal cancer from coming back
DTPx Therapeutics won $100,000 from FACIT to develop a new treatment by targeting hibernating cancer cells.
Dr. Sumaiyah Rehman

DTPx Therapeutics won $100,000 from FACIT to develop a new treatment by targeting hibernating cancer cells.

For many people with colorectal cancer, treatment can be a vicious cycle.

Even when it looks like chemotherapy killed their tumour, as many as 40 per cent of colorectal cancer patients will see it grow back within a few years. If they undergo another round of treatment, the tumour will go away again, only to come back after treatment is done.

This cycle of treatment and recurrence is very tough on patients, and many will ultimately die from the disease.

But scientists at DTPx Therapeutics think they’ve found the key to stopping the cycle and treating colorectal cancer once and for all. They pitched their innovative approach at this year’s Falcons’ Fortunes, a competition for Ontario-based cancer entrepreneurs run by OICR’s commercialization partner FACIT, and took home the $100,000 top prize as well as the audience choice award.

The research behind DTPx came out of Dr. Catherine O’Brien’s lab at Princess Margaret Cancer Centre. O’Brien and colleagues found that some colorectal cancer cells went into a hibernation state that allowed them to survive treatment and then grow again once the treatment was done. They called these cells ‘drug tolerant persisters’ (DTP) and launched DTPx Therapeutics to turn their new findings into new treatments.

Dr. Sumaiyah Rehman is CEO and co-founder of DTPx alongside O’Brien. She recently spoke to OICR News about her research and how winning FACIT’s Falcons’ Fortunes will help the company achieve its goals.

Tell us about DTP cells and their role in colorectal cancer relapse.

When you treat a tumour with chemotherapy, you expect most tumour cells to die. But DTPs can survive the toxic environment created by chemotherapy by entering what we call a ‘hibernation state’. Their functions slow down and they stay alive just enough until treatment stops, and then they’re able to regrow. That’s why many patients with colorectal cancer see their tumours respond to treatment, and it looks like it is gone, but then it comes right back.

How did Dr. O’Brien’s lab come upon this discovery about DTPs?

We started out studying drug resistance, because we thought the relapse cycle in colorectal cancer was driven by resistance to chemotherapy. We did several experiments where we injected patient-derived samples of colorectal cancer into mice, treated them with chemotherapy and then tracked the tumour cells to see what happened.

We expected to find one type of cell that resisted treatment. Instead, we found that all different types of tumour cells came back after treatment. The tumour that recurred looked just like the original tumour. That was surprising, and it took us down a different path to understand how all these cells had survived chemotherapy. That led us to our discovery about DTPs, which we published in Cell in 2021 and became the foundation of DTPx Therapeutics.

How is DTPx using this knowledge about DTPs to create new treatments?

It all starts with the patient-derived models we developed over several years of studying tumour relapse in colorectal cancer. The models allow us to grow tumours, put tumours cells into a hibernation state and then harvest them. We can then do all sorts of analyses to understand how these cells go into hibernation and look for parts of that process we can disrupt by targeting them with new therapeutics.

We’ve found some exciting leads so far. There’s still a lot of work ahead, but with the network we have in place, and support we received from FACIT, we’re looking forward to finding a druggable target as soon as possible.

Speaking of FACIT, what was it like pitching at the Falcons’ Fortunes competition?

Honestly, it was nerve-wracking. I have done pitches before, but this was on a larger scale than I’m used to. There were a lot of fantastic ideas pitched that night, and I did not expect to win. It’s very exciting and humbling to win, and every step of the process has been a great learning experience.

As you and DTPx move forward, what do you hope you can accomplish in the future?

Once we finalize our target and develop the drug, my goal is to stop patients from having to go through the cycle of treatment and relapse, and to take the survival rate for colorectal cancer up to 100 per cent.

I remember my first day of grad school. A clinician scientist came up to a group of us grad students, pointed over toward the hospital side of the institution, and told us: “Your job isn’t done until you’ve made a difference over there.” That stuck with me. There’s no point in doing fancy science if it’s not going to make it out of the lab. And that’s what drives us at DTPx.

Now in its tenth year, FACIT’s Falcons’ Fortunes is an annual pitch competition featuring six finalist Ontario-based entrepreneurs in the oncology sector who pitch their innovations to a panel of industry-experienced investors for the $100,000 Ernsting Entrepreneurship Award. The Award is part of FACIT’s Prospects Oncology Fund, one of FACIT’s investment programs that seeks to create value for Ontario’s cancer intellectual property by addressing the seed funding gap for early-stage, proof-of-concept projects with commercial potential.