German American RNA editing biotech AIRNA has raised $60 million, to add to an earlier $30 million in initial funding, to close an oversubscribed Series A fundraising round. The earlier funding was announced last September when the company emerged from stealth mode.
The new fundraise was led by European VC firm Forbion, with contributions from Ono Venture Investment, Alexandria Venture Investments and others. Existing investors from the earlier fundraise also contributed, for example, ARCH Venture Partners and ND Capital.
AIRNA is using double-stranded RNA-specific adenosine deaminase (ADAR) enzymes to create treatments for genetic diseases by changing single bases on the mRNA. Naturally occurring ADAR enzymes bind to RNA and convert adenosine to inosine, changing the activity of the resulting protein. This editing method can be used to repair a disease-causing mutation or activate or deactivate a gene to induce a therapeutic change in the protein.
Co-founded by RNA editing expert Thorsten Stafforst, a professor at the University of Tübingen, and Jin Billy Li, a geneticist and professor at Stanford University, AIRNA is one of several companies hoping to harness the RNA base-editing potential of ADAR enzymes to target disease.
“Precisely editing RNA started as an idea in my lab over a decade ago,” said Stafforst, in an earlier press release. “After making several technological improvements, I’m excited to see AIRNA advancing RNA editing therapeutics into precise medicines that could really impact patient’s lives.”
The company plans to use the Series A money to develop its lead candidate to target alpha-1 antitrypsin deficiency (AATD), as well as finding new candidates and targets to add to its pipeline.
A good ADAR target
AIRNA is not the only company targeting AATD using ADAR-based technology. Wave Life Sciences is collaborating with GSK on a similar therapy, which is currently at phase 1. Korro Bio and ADARx are also working on ADAR-based therapies for the same target but, like AIRNA, are still at the preclinical stage.
AATD impacts between 1 in 3000 and 1 in 5000 individuals and is caused by inherited mutations in the SERPINA1 gene. There are several mutations responsible for the condition, so severity varies between individuals. For example, some people are affected in childhood, but others don’t experience symptoms until adulthood.
Although there are many genetic variants causing AATD, the most common mutation causing severe disease is a single base-pair substitution resulting in a glutamic acid to lysine mutation, which makes is a good target for RNA base editors such as those being developed by AIRNA.
AATD primarily affects the lungs and the liver with those affected at high risk for conditions such as chronic obstructive pulmonary disease and liver failure or cirrhosis. Current treatments focus on symptoms, but don’t address the underlying cause of the disease. For this reason, an ADAR-based RNA editing treatment such as the one being developed by AIRNA could help address an important unmet need.