Serif Biomedicines has emerged from stealth with $50 million in start-up funding. The new firm is developing what it calls “modified DNA” as a new class of therapeutics that may be better at introducing new genetic material than gene editing therapies.
Gene editing can fix an error in existing DNA, says Serif cofounder and CEO Jake Rubens, but DNA therapy can introduce a whole new piece of code as an episome, or a little island of DNA separate from the main chromosomes. This approach is different from something like bridge editing, which integrates new code into the genome.
The problem with DNA medicine, however, is that many viruses try to infect cells with foreign DNA, and so the immune system has developed powerful defense mechanisms against DNA coming in through the cytoplasm. Serif is solving that problem by modifying DNA structures and enveloping them in lipid nanoparticles, making them more resistant to cellular defense mechanisms.
The work of messenger RNA vaccine pioneers Katalin Karikó and Drew Weissman, who shared the Nobel Prize in Medicine in 2023, was “hugely instructive,” Rubens says. The specific modifications Serif is making to DNA have not been disclosed, but Rubens was willing to share that circular DNA tended to work better than linear DNA, and that they had luck with both single-stranded circular DNA and double-stranded circular DNA with one modified and one unmodified strand. The firm has also not disclosed potential therapeutic targets. More details may emerge when Serif presents preclinical data at an upcoming scientific meeting.
2026 American Chemical Society
