Can a new protein bring RNA drugs where they can't reach? J&J vet Sue Dillon's Ionis-partnered biotech gets $88M to prove yes
Sue Dillon remembers the uncertainty when she first left J&J to start her own biotech around a new kind of molecules called centyrins.
J&J had already licensed the tech, which was developed by her co-founder Karyn O’Neil at the pharma giant’s Centyrex unit, to two companies for use in CAR-T and radiopharmaceuticals. But Aro Biotherapeutics wanted to apply it to what was still a nascent area: RNA medicines, encompassing both antisense oligonucleotides and siRNA therapies.
“There was a lot of skepticism out there around whether or not oligonucleotides would become a significant drug platform,” she told Endpoints News. “I don’t think anybody doubts that now.”
For all the progress, though, the need that the duo saw remains. Outside the liver and certain diseases primed for local delivery, drugmakers have had trouble delivering these drugs to other tissues. Aro’s proposed solution was promising and pertinent enough that after J&J provided the initial $13 million to get things off the ground, Ionis, a giant in the antisense nucleotide field, signed up for a discovery pact at the beginning of 2020.
One year later, Dillon and O’Neil are ready to steer their own candidates toward the clinic, armed with $88 million in Series A funding provided by the existing investors at Johnson & Johnson Innovation – JJDC, Ionis and BioMotiv, as well as new backers led by Northpond Ventures and Cowen Healthcare (the others are HealthCap, BVF Partners and Ridgeback Capital).
If the concept checks out — and Aro is leaning on some serious proof-of-concept from O’Neil’s J&J days that it would — it promises to change not just antisense but a slew of genetic medicines that are reshaping the definition of a drug.
Centyrins, Dillon explained, are modeled on a human protein from the fibronectin family that vaguely resembles an antigen binding domain of a very large antibody. They are small (just one-fifteenth the size of an antibody) but bind to cell surface receptors with high affinity, and they can be easily manufactured in E. coli in the lab.
Not only has O’Neil figured out a way to conjugate them to RNA molecules, her team can also create bispecific or multispecific centyrins to select for certain cells that have all the receptors.
The company isn’t saying much about the pipeline other than that the initial programs will target muscle diseases and immunology — Dillon’s expert area at J&J — and range from the rare, orphan disorder to more common ailments. As is common for an early-stage venture, the CEO also refrained from committing to a timeline for entering the clinic but noted the funding should last them two to three years.
In parallel with the lead programs, the team of 20 is also exploring ways to systemically deliver mRNA, DNA or CRISPR/Cas machinery — anything that’s wrapped in nanoparticles — to target tissues.
“I think that the biggest single thing over the last 3 years is the emergence of broadly genetic medicines as the major class of medicines for the future, and along with that, the recognition that a major challenge facing the entire field of any of those types of medicines is the challenge of tissue specific delivery,” Dillon said. “That’s where Aro comes in. And that’s why I believe even more than I did in 2018 when we first started the company that there is just enormous potential here for us to really make a difference.”