RNA medicines can treat some diseases by hitting targets otherwise considered “undruggable” by small molecules and biologics, but protecting the nucleic acids from degradation and getting the therapies to where they are needed in the body can be difficult.
San Diego startup DTx Pharma has raised $10.6 million to advance technology it has developed that uses fatty acids in an effort to overcome delivery and distribution issues. The sum includes an undisclosed amount from Eli Lilly (NYSE: [[ticker:LLY]]), which has made a number of investments in biotechs pursuing RNA-focused technologies.
DTx, which is based at the Johnson & Johnson (NYSE: [[ticker:JNJ]]) JLABS incubator in La Jolla, CA, was founded in August 2017. The startup aims to improve upon existing delivery systems for drugs that target RNA, which could allow the medicines to be more widely circulated and more easily penetrate tissues and organs.
“Antisense molecules are not efficiently taken up by cells, so they usually need a chaperone,” CEO Artie Suckow CEO says. Once they are, “they’re rapidly cleared by the kidney, so they need help.”
DTx’s chaperones of choice are fatty acid molecules. The biotech describes its technology as an Uber-like system designed to carry antisense molecules through the body’s circulatory system to tissues beyond the liver and kidney, and in doing so increasing the period of time that cells are exposed to the drug and can take it up.
The technology connects the drugs with fatty acids, which bind with a common protein called albumin that carries substances through the blood. Fatty acids can bind with a variety of cells types, unlike a popular delivery mechanism for RNA drugs referred to as GalNAc, a naturally occurring sugar, which binds to hepatocytes, the most common type of liver cell.
Fatty acids are already in use today by developers of some peptide drugs, such as insulin, to increase their half-life.
DTx emphasizes that its approach is distinct, however, from another method in the field: encapsulating RNA within lipid nanoparticles. That’s what Alnylam Therapeutics (NASDAQ: [[ticker:ANLY]]) does to deliver its drug patisiran (Onpattro), an RNA interference (RNAi) medicine. That gene-silencing drug was OK’d by the FDA to treat hereditary transthyretin-mediated amyloidosis.
The biotech is doing preclinical work on compounds for ophthalmology, muscle disorders, and conditions that affect the central nervous system. Jeff Friedman, DTx’s chief operating officer, says it also is seeking out potential partnerships with companies with RNA drugs that DTx believes its technology could improve.
“We’re advancing our own internal programs, which are very clearly showing that molecules that are either identical to or very similar to the ones that those companies have developed can be improved,” he said. “We are [also] beginning discussions with the relevant companies about approving their existing drugs, coming up with version 2.0 for their pipelines.”
Friedman Bioventure Fund, a biotech fund that Friedman manages, led the Series A round. Other investors include Viva Biotech, a Shanghai-based company, Tech Coast Angels San Diego, and ExSight Ventures, which supports innovations in ophthalmology.
“We have a technology that I think has very high potential value, and we’re going to find out over probably the next two years if we’re able to realize that value,” Friedman said.
Lilly has also invested in San Diego’s Avidity Biosciences, which is designing drugs called antibody-oligonucleotide conjugates that use fragments of antibodies to target receptors on specific types of cells. The biopharma participated in Avidity’s recent $100 million Series C round. The year before Lilly forked over $200 million—half up front, half an equity investment—to Boston’s Dicerna Pharmaceuticals, an RNAi medicines developer.
As part of the DTx deal, Friedman, Lilly’s Andrew Adams, Arena Pharmaceuticals (NASDAQ: [[ticker:ARNA]]) vice president of nonclinical development and clinical pharmacology John Grundy, who co-founded the company, and TEGA Pharmaceuticals CEO Tim Scott join the DTx board of directors.
