Investors fund Prometheus team's 'unfinished business' with $400M for new inflammatory biotech Mirador

Having some free time following the $10.8 billion buyout of Prometheus Biosciences made Mark McKenna realize he had some “unfinished business.”

Prometheus had managed to create a therapeutic that improved efficacy in inflammatory bowel disease from about 15% to over 25%. But what about the other 75%?

“Everyone had a few months off, everyone sat on the beach, everyone played a lot of golf,” McKenna said in an interview with Fierce Biotech.

And now they’re back, with a brand-new biotech called Mirador Therapeutics and a massive $400 million series A funding round—the biggest of 2024 so far. Mirador emerged today to develop precision medicines for inflammatory and fibrotic diseases, with an initial focus on gastrointestinal tract, lung and skin diseases, according to CEO McKenna.

The round was led by Arch Venture Partners, plus OrbiMed and Fairmount. Other participants included Fidelity Management & Research Company, Point72, Farallon Capital Management, Sanofi Ventures, RTW Investments and Alexandria Venture Investments.

Mark McKenna, Mirador
CEO Mark McKenna (Mirador Therapeutics)

McKenna’s new enterprise is formed around the Mirador360 platform—which he refers to as an “engine.” The technology uses data from millions of patient molecular profiles to find genetic targets for immuno-fibrotic diseases. This also includes a diagnostic component to find the right patients for the right therapy.

While the team is similar, Mirador’s massive raise sets it apart from the journey Prometheus took. The former company, now a part of Merck & Co., emerged pre-COVID and snagged just $50 million in a series B financing. McKenna said the team struggled with few investors in the early years, but, ultimately, the data proved the point, and Prometheus was acquired for $10.8 billion.

“Nothing about Prometheus was easy. And I think that also made the journey more rewarding, but it also created this team that has a DNA of being able to solve big problems,” McKenna said. “There were a lot of white-knuckle moments as we repositioned the company, and took an early science idea and moved it in the clinic.”

Prometheus proved that precision medicine had a place outside of oncology, which caught the eye of not only Merck but more than a dozen companies that pursued a buyout.

The biotech’s anti-TL1A medicine PRA023 put 26.5% of recipients with ulcerative colitis into clinical remission by Week 12 during a midstage trial. Prometheus went up against Pfizer in the space, “outflanking” the pharma giant, which ended up divesting its TL1A program first to Roivant and then officially to Roche for $7.1 billion in October 2023.

“The last two years were a tremendous amount of fun and we were firing on all cylinders. We were demonstrating what good execution looks like, and the fact that speed today is the new currency in biotech,” McKenna said.

When it came time to figure out his next venture, McKenna knew who to call to build out the executive team. McKenna will be joined by Olivier Laurent, Ph.D., as chief scientific officer, Vika Brough as CFO, Allison Luo, M.D., as chief medical officer and more, all from Prometheus. 

The success of Prometheus also made fundraising for Mirador easier. Instead of taking a year for the initial raise like Prometheus, McKenna said the Mirador team raised the cash in about 60 days. Many of the investors came over from Prometheus, but some new investors were welcomed as well.

It's safe to say the $400 million raise defied expectations, and, because of that, the new biotech is in a position to build out a pipeline. The capital will, of course, be used to advance multiple internal programs into the clinic, but McKenna is also looking for deals that Mirador could “supercharge” with its precision medicine approach.

“The bar is extremely high. I would just say that we're going to be very diligent in terms of how we think about external innovation in the same way we do it internally,” McKenna said.

While operating in stealth, Mirador has been active in talking to potential partners, including at the J.P. Morgan healthcare conference in January. Without mentioning specifics, McKenna said that includes small biotechs to Big Pharmas, and he expects some deals to land in “the coming quarters.” The goal is to accelerate Mirador into a clinical company.

But that doesn’t mean Mirador is slow-walking its internal pipeline. McKenna expects to hand an investigational new drug application to the FDA next year. Mirador will be taking lessons from oncology as well as the Prometheus experience to build out a pipeline of therapies.

“We've seen this pay off in spades in oncology, why not immunology?” McKenna said of precision medicine.

Another way Mirador will echo advancements in cancer is in combination approaches to treatment. He added: “This is a much more elegant and accelerated version of what we were doing before. You learn a lot through these processes of building companies and running trials. And there's new approaches that allow us to move the field forward.”