Dive Brief:Airna, a biotechnology startup developing RNA editing treatments, said Tuesday it raised $155 million in a Series B round that will help propel its lead program in alpha-1 antitrypsin deficiency into the clinic later this year.That medicine, codenamed AIR-001, repairs faulty RNA transcribed by the gene thats mutated in alpha-1 antitrypsin deficiency, or AATD. When the RNA is edited, cells are able to produce functional copies of AAT protein, lowering the risk of associated lung and liver disease.Airnas raise comes nearly six months after Wave Life Sciences unveiled promising Phase 1 data for an RNA editing drug also aimed at AATD. Similar to Wave, Airnas drug uses a sugar molecule to take its medicine into the liver.Dive Insight:No cure currently exists for AATD, which in some patients is managed with weekly injections of AAT protein. Airna estimates approximately 100,000 people in the U.S. have AATD.Co-founded by professors Thorsten Stafforst at the University of Tubingen and Jin Billy Li at Stanford University, Airna hopes to fill that niche with technology that can recruit an enzyme known as adenosine deaminase acting on RNA, or ADAR, to modify RNA.Kris Elverum, Airnas CEO, said the appeal of a drug like AIR-001 is its resemblance to biologic drugs, rather than experimental gene therapies that permanently alter DNA and can be costly to manufacture. AIR-001 is administered via a subcutaneous injection and its developers are experimenting with how to maintain its potency at lower dosages.Patients and physicians want to be able to have options that can give them a functional cure while maintaining flexibility and control over their healthcare decisions, Elverum said.The company has not disclosed specific conditions its targeting outside of AATD, but co-founder Stafforst has published research on the applicability of RNA editing in cardiometabolic and neurodegenerative diseases.RNA editing is not going to be the solution for every disease and every target, but what our data suggests is that the physiological effects of healthy variants that we identify can be reproduced through a single RNA edit, Elverum said.The Series B round was co-led by Venrock and Forbion, and included investors such as RTW Investments, Arch Venture Partners and Nextech Invest. Airna previously raised $90 million after emerging from stealth in 2023.Startups such as Shape Therapeutics, Ascidian Therapeutics and ADARx Pharmaceuticals, as well as established biotechs such as Wave and Korro Bio, have turned to RNA editing for tough-to-treat diseases. While the field has drawn hundreds of millions of venture capital dollars and the attention of pharma partners such as Roche and Novo Nordisk, its unclear whether any drugs resulting from that investment will succeed in finding a treatment niche.Airnas innovative approach to RNA editing has the distinctive potential to improve health across large populations by introducing healthy genetic variants for many conditions, Derk Kersten, a managing partner at Forbion, said in a statement. '