When constructing a house, certain jobs require different tools. New medicines are no different, says Trevor Martin, cofounder and CEO of Mammoth Biosciences, which is building one of the largest repositories of Crispr-based proteins to cut and edit DNA for use in medicines and diagnostics. “Different proteins have different properties that are good for different applications, so it’s kind of similar to having a hammer and a screwdriver and a power drill,” says Martin, cofounder and CEO of the South San Francisco-based company. That’s because some proteins are much smaller in size, able to withstand certain temperatures or have expanded targeting ability. Certain ones, he says, “are really good for therapeutic applications, some for diagnostics and some for both.”
On Thursday, Mammoth announced the company raised $195 million of financing at a valuation of more than $1 billion. The funding includes a $150 million Series D led by Redmile Group and a $45 million Series C, also led by Redmile Group and Foresite Capital, with participation from Sixth Street, Decheng Capital, Mayfield and Amazon, among others.
Investors are betting the protein toolbox of the four-year-old startup cofounded by Forbes Under 30 alums Martin, 32, Janice Chen, 30, and Lucas Harrington, 30, along with the Nobel Prize winning chemist Jennifer Doudna, 57, can solve one of gene editing’s trickiest problems: getting therapies into the patient’s body. This is known as in vivo therapy, where the editing tools can be administered directly into the body, compared to ex vivo editing, where cells are removed from the patient, treated and returned back into the body. Mammoth has not publicly released its specific therapeutic targets, but has said that it’s focused on liver diseases, neurology and immuno-oncology, among others.
To target these areas, Mammoth is focusing on two proteins — Cas14 and Casɸ — which could be particularly helpful for in vivo gene editing because of their ultra-small size. There are a couple of ways to get gene editing therapies into humans, including adeno-associated viruses. Think of the virus cell as a cargo truck that is filled up with the tools that make up the therapy. Some of the legacy Crispr systems are so big they barely fit into the truck, Martin says. “But with our ultra small systems like Casɸ, it’s just one box in the truck with tons of room for other cargo. And it really unlocks a lot of potential.”
One of the lasting legacies of Covid is it finally shows the world why founder-led companies are important in life sciences.
The Covid-19 pandemic served as a proof point to show how quickly Mammoth’s Crispr-based diagnostic products could be spun up, after the importance of diagnostics had been somewhat overlooked, says Martin. “What’s really powerful is that when you combine a field that’s maybe underappreciated with a very transformative technology like Crispr, that’s when you can really have like a magical level of impact and really kind of transformed people’s lives for the better,” says Martin. The Mammoth team was able to quickly ramp up its work around Covid-19 in partnerships with companies including GlaxoSmithKline and MilliporeSigma (part of Germany-based Merck KGaA). Its diagnostic solution was selected for the RADx program, a “shark-tank” style challenge led by the National Institutes of Health, as well as a contract with the Department of Defense. Mammoth received an emergency use authorization for its DETECTR diagnostic platform for Covid-19 from the FDA last summer.
“The 21st century is really going to be the century that is defined by engineering biology,” says Jeff Huber, the founding CEO of cancer diagnostics company Grail, who is an investor in Mammoth and joined the company’s board last year. The revolution started with the Human Genome Project and the ability to read DNA, he says. “Now with Crispr and related technologies, not only can we read and understand, but increasingly we can write and engineer.”
Partnerships like those Mammoth entered into for Covid diagnostics will be crucial for the company to execute at scale, says Huber, and are key to Mammoth’s growth strategy. The company has expanded to over 100 employees, up from 35 last year and recently opened a new facility in Brisbane, California. Mammoth also hired former Genentech and Sangamo executive Gary Loeb as the company’s general counsel. Cofounders Martin, Harrington and Chen continue to lead the company.
“One of the lasting legacies of Covid is it finally shows the world why founder-led companies are important in life sciences,” says Ursheet Parikh, a partner at Mayfield who invested in Mammoth at seed stage. He points to Ugur Sahin and Özlem Türeci, the husband and wife founding duo behind BioNTech and Stéphane Bancel, the CEO of Moderna, who joined the company in its first year of operations, and whose companies developed Covid-19 vaccines in record time. Mammoth, like Moderna, is a platform-based biotech, meaning it is not putting all its eggs in one therapeutic basket, but is instead betting on the fundamental Crispr technology that could have wide-ranging applications across a number of diseases.
“Just as we look at Intel, Microsoft, and Apple as the building blocks of the tech economy of the future,” Mammoth plays a similar role in biotech, says Parikh. “Without Mammoth, every company would have to reinvent the wheel on learning Crispr,” he says. A decade from now, many more Crispr-based products will be in the market “because Mammoth just made it easier to build and make them better and more effective.”