Maze Therapeutics debuts with $191M to go after genetic modifiers

The funding will allow Maze Therapeutics to carry out a two-pronged strategy—to develop its platform and to advance three programs. (Getty/NosUA)

Third Rock Ventures launched Maze Therapeutics with $191 million in committed capital and a mission to “translate genetic insights into new medicines.” The biotech aims to make sense of the proliferation of human genetic data that has emerged in recent years and understand how some genes provide protection against disease so that they can be targeted with drugs. 

Maze is trying to figure out why some people with genetic mutations linked to severe disease end up having only mild symptoms. To that end, the San Francisco biotech isn’t focusing on the disease-causing mutations themselves. Instead, it's interested in genetic modifiers, that is, genes elsewhere in a person’s DNA that affect the severity of disease and act as a “natural form of protection.” It is building a platform to “interrogate the remarkable amount of human genetic data that’s available,” develop disease models in cells, identify genetic variations that affect disease severity, and then target them. 

“The validation of targets is the most important risk in a drug discovery effort. There are more risks later, such as regulatory and pricing risks, but the validation of the target is the greatest risk. And I think that is what genetic modifiers offer—the understanding of genetic modifiers offers a roadmap to genetically validated targets,” said Charles Homcy, Maze Therapeutics’ founder, interim CEO and a partner at Third Rock. 

The new financing comes from ARCH Venture Partners, GV, Foresite Capital, Casdin Capital, Alexandria Venture Investments and some undisclosed investors, in addition to Third Rock. It will allow the company to carry out a two-pronged strategy—to develop its platform and to advance three programs devised from looking at existing literature and analyzing human genetic data. 

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The first program is a small molecule for an undisclosed disease and the second is a gene therapy for a neurodegenerative disease, Homcy said. The third is “in a totally different therapeutic space.” Maze reckons it can get proof of mechanism in healthy volunteers for the first treatment in two and a half to three years, and in the same time frame get the second program into the clinic as well. And that’s why it needed such a big fundraise. 

“What was required to do that was not a normal raise,” Homcy said. "If we had done a normal $55 million series A alone with Third Rock, we could pursue the drug discovery program, but not the platform in a way we think would make this a very competitive effort.” 

Since starting out a couple years ago, Maze has grown to between 25 and 30 staffers, “essentially all scientists, with some infrastructure.” The biotech is occupying a temporary space in Redwood City, California, before it moves to a larger site in South San Francisco this spring. 

“By the end of 2019, we will probably grow from nearly 30 to nearly 50 people. A lot of that will be building out our platform capabilities,” Homcy said.