What happens when the scalability and redosability of messenger RNA (mRNA) is combined with the durability and programmability of gene therapy?
According to Serif Biomedicines, a five-year-old startup that emerged from stealth mode this month, the result is “modified DNA,” a new class of therapeutics designed to be programmable, durable, scalable, and redosable—while minimizing the drawbacks of both mRNA and gene therapy.
Modified DNA builds upon generative protein and mRNA platforms created by Flagship Pioneering, the venture capital giant which founded Serif in 2021. On April 21, Flagship formally launched Serif with an initial commitment of $50 million in financing—capital that Serif intends to use toward developing its scalable platform for optimizing and manufacturing Modified DNA treatments, aided by artificial intelligence (AI), and advancing its first drug discovery programs.
“The reason we’re bringing the company out of stealth mode now is we think we have made progress. We’ve made real progress that we’re excited to share with the world, that we’re excited to get feedback from the broader scientific community on, and we want to tell that story more broadly,” Jacob (Jake) Rubens, PhD, Serif’s co-founder and CEO, and an Origination Partner at Flagship Pioneering, told GEN.
“It’s been on our minds for a long time: What might be possible when DNA becomes an engineerable biotechnology for the first time?”
It’s a question pursued by numerous researchers and companies over the years as they sought to capitalize on DNA’s qualities of being a durably expressing molecule capable of coding for any gene, producing proteins or RNAs in a cell-specific way, as well as being scalable to manufacture and capable of re-dosing for patients.
“Those are, I think, the key differentiating attributes of theoretical DNA medicines. So the question for us became not, would this be valuable if we could do it, but why hasn’t anyone done it yet?” Rubens explained. “We’ve known about the centrality of DNA in biology, the central information molecule in DNA. We’ve known this for 75 years since Watson and Crick’s seminal discoveries around how the structure of DNA enabled it to function as an information molecule.”
Two key problems
“And when we looked at this space,” he continued, “we saw that there were two key problems: The first is that DNA is a highly inflammatory molecule. The second is that DNA needs to be delivered not just into a cell, but into the nucleus, the center of the cell.”
To create Modified DNA, Serif alters the structural and chemical form of DNA in order to minimize innate immunogenicity as lipid nanoparticles drop off the DNA not in the nucleus, but in the cytoplasm of the cell.
Once inside the cell nucleus, Modified DNA reverts to unmodified DNA, enabling transcription into therapeutic RNA and proteins. The resulting treatments are designed to last longer, be given more than once, and be programmed for cell-specific expression. To enhance durability, Serif delivers with its Modified DNA proteins which help the DNA access the nucleus. The proteins, called mRNA co-factors, are designed to transiently express proteins that enhance entry into the nucleus and gene expression.
Pending an announcement it expects to make later this year, Serif isn’t revealing specifics of its initial drug discovery programs, except to say that they focus on rare diseases and immune programming.
“This is not meant to be a limited list of where we could go but the areas that we think we’re going to go first, which are likely in addressing protein deficiencies in genetic diseases,” Rubens said.
Modified DNA has shown itself to be disease agnostic, he added, reflecting DNA’s qualities as a general, programmable information molecule: “One of the reasons we’re so excited about, the future of modified DNA as a new biotechnology akin to RNA, akin to protein, is its centrality in biology. It is the fundamental information molecule inside of all of us, inside of every living thing on this planet. So that is really the existence proof that it is generalizable.”
Tolerability and sustained expression
Also later this year, Serif plans to present data at an as-yet-unspecified scientific conference that will show modified DNA’s tolerability in non-human primates, as well as sustained gene expression with therapeutic effects in preclinical models following intravenous (IV) administration.
Serif aims to transform Modified DNA into treatments as effectively and commercially successfully as Amgen, Genentech (now a member of the Roche Group), and later Regeneron did with engineered proteins, as Alnylam Pharmaceuticals did with small interfering RNA (siRNA), and as Moderna more recently accomplished with mRNA—most notably in developing its SpikeVax® COVID-19 vaccine, which the FDA authorized for emergency use in 2020 and fully approved in 2022.
Flagship launched Moderna in 2010; the company went public in 2018 by raising $604 million, the largest-ever U.S. biotech initial public offering (IPO) until Kailera Therapeutics raised $625 million earlier this month.
At Flagship, Rubens is a scientist entrepreneur who leads the firm’s Pioneering Business Unit, which establishes and grows companies based on new biotechnology. In addition to Serif, Rubens co-founded Quotient Therapeutics, which develops therapies based on its somatic genomics platform; Tessera Therapeutics, which writes therapeutic messages into the genome through a genome engineering approach called GeneWriting
; and Sana Biotechnology, a developer of treatments based on engineered cells. He also launched Kaleido Biosciences, a microbiome therapeutics company that ceased operations in 2022.
Before joining Flagship, Jake received his PhD in microbiology from MIT, working with Tim Lu, MD, PhD, a core member of the Synthetic Biology Center, through the support of a National Science Foundation Graduate Research Fellowship. At MIT, Jake helped enable “intelligent” cell therapies by inventing gene circuits that allow engineered cells to do novel analog, digital, and hybrid computations.
Based in Cambridge, MA, Serif employs about 50 people and as of Wednesday was disclosing five open positions on its website in its three areas of focus: Chemistry (associate scientist and senior scientist, both specializing in LNP formulations), Molecular Biology (research associate and senior scientist), and Research/Discovery (scientist specializing in bioanalytical assays).
“I’m not at this point going to provide any guidance on how much more we will or won’t grow,” Rubens said. “We’re quite agile and responsive to the company’s needs.”
The post ‘Type’ Casting: Flagship-Founded Serif Modifying DNA into New Therapy Class appeared first on GEN – Genetic Engineering and Biotechnology News.
