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Investors bet big on Feng Zhang’s new startup, out to solve one of gene editing’s most vexing problems

Aera Therapeutics is launching with $193 million to develop a new nanoparticle technology to deliver genetic medicines to hard-to-reach parts of the body.

Gene editing researcher Feng Zhang founded Aera Therapeutics to develop therapies based on a new gene delivery technology invented in his lab at the Broad Institute of MIT and Harvard.Aera Therapeutics

Months before Feng Zhang met with a trio of investors from GV, the venture capital arm of Google’s parent company Alphabet, the scientist had been dropping hints that his lab at the Broad Institute of MIT and Harvard was working on something big. When he sat down for dinner at the Liberty Hotel in the summer of 2021, he was finally ready to talk about it.

By the time the group finished appetizers, Zhang had convinced the table that he may have devised a new solution to one of the most vexing problems in biotech: how to deliver potentially curative genetic medicines to hard-to-reach parts of the body, such as the brain, heart, and muscles.


The outcome of that dinner was a new biotech startup, founded by Zhang in the fall of 2021. After a year-and-a-half of working in stealth, the company, Aera Therapeutics, formally launched Thursday morning with $193 million in financing from GV and other investors including ARCH Venture Partners and Lux Capital.

The Boston company is devising a new nanoparticle technology based on previously overlooked human proteins that assemble into virus-like structures. With a little tinkering, Zhang showed that they can be used to sneak medicines based on the genetic molecule RNA into human cells grown in a dish.

If Aera’s approach works in people, it could broaden the reach of genetic therapies, which currently have limited clinical applications — partly because there aren’t enough methods for getting those medicines to hone in on the right cells.

Aera’s launch comes during a period of economic turbulence that has made it hard for some biotech startups to raise money to continue developing their therapies and test them in clinical studies. But Aera’s investors appear to be playing the long-game, wagering that Zhang’s new technology could make waves even though it is likely several years away from being tested in humans.


“It is very early science, but super exciting, and if it works, very transformative,” said Issi Rozen, a venture partner at GV who knew Zhang well from his prior position of chief business officer at the Broad Institute. “This is a company that we knew would need to mature over the next few years and develop the value of its technology. And we’re willing to wait and build it right.”

Aera won’t disclose any specific diseases that it is working on, or even tip its hand to the parts of the body that Zhang’s new delivery technology might conquer. “I think it’s premature for us to be thinking about applications,” said chief executive Akin Akinc.

That a biotech company can raise so much money when tangible ideas for therapies are so far away is partly a reflection of the vast potential a new delivery technology would have, and partly a statement of trust in the technology’s creator.

The main building of the Broad Institute in Cambridge on Dec. 28, 2020. Pat Greenhouse/Globe Staff

Zhang made a name for himself as one the inventors of CRISPR gene editing, a technology that promises to revolutionize treatments for cancer, genetic diseases, and more by making precise and permanent changes to the human genome. Several Boston companies, including ones founded by Zhang, are already developing CRISPR therapies, and the first medicines based on the gene-altering technology may be approved within the next year.

Many gene editing companies are focused on editing blood or immune cells, since they can be readily removed from the body, altered in the lab, and reinfused. Others are working on editing cells in the liver, since therapies delivered by engineered viruses or lipid nanoparticles — the mainstay delivery vessels of genetic medicine — tend to get stuck in that organ after infusion.


But in order for CRISPR to reach its full potential, Zhang felt there was an “urgent need” to develop new delivery strategies. “Delivery is the major bottleneck,” he said.

After reading about an intriguing human protein that could form virus-like structures, Zhang’s team began a fishing expedition through the human genome looking for similar proteins that could be harnessed to package and deliver genetic material.

The results of that search led to the discovery of one especially useful protein that became the backbone of a new nanoparticle technology, dubbed SEND, which was published in the journal Science soon after Zhang’s dinner with the GV investors. Aera has licensed the SEND technology, along with new gene editing enzymes discovered in Zhang’s lab, from the Broad Institute.

The fact that the proteins used in SEND are made in the human body is key, Rozen said, because it suggests that our immune systems will be less likely to reject it, hopefully making it easier for the therapy to slip into cells undetected.

Aera will likely focus on diseases that can’t be treated by editing the liver or by removing cells from the blood. “There’s so many other tissues that are completely unsolved, and if we could do something there, it would really move the entire field forward,” Akinc said.


The startup has about 50 employees and sublets a lab from Vertex Pharmaceuticals in Boston’s Seaport. Akinc said that he plans to add 30 people to Aera this year and move the company to Kendall Square, the biotech hub of Cambridge.

Until recently, Akinc spent 20 years at Alnylam Pharmaceuticals in Cambridge, where he helped pioneer the development of RNA medicines that can silence disease-causing genes in the liver. One of the major hurdles for that new class of drugs was figuring out how to deliver them into cells safely.

Aera reminds him of the early days of Alnylam, and he hopes to replicate the success there at his new company. “I’m hoping to do it all over again,” he said.

Ryan Cross can be reached at Follow him on Twitter @RLCscienceboss.