AIRNA has raised $155m in Series B financing to advance its RNA editing pipeline, and kick-start a clinical trial for its lead candidate, AIR-001.

Venrock Healthcare Capital Partners and Forbion Growth co-led the new round, bringing AIRNA’s total raised capital to $245m. The US and Germany-based biotech plans to file a clinical trial application (CTA) for its lead candidate, AIR-001, for alpha-1 antitrypsin deficiency (AATD) by H2 2025.

The company is developing AIR-001 as an investigational RNA editor – a therapy designed to modify RNA sequences to correct disease-causing mutations. This approach is different to DNA editing approaches such as clustered regularly interspaced short palindromic repeats (CRISPR), which make permanent changes to the genome. RNA editing is a reversible process that allows for targeted corrections without altering the underlying genetic code.

The Series B funds will support the launch of a Phase I/II clinical trial for AIR-001 and the further development of other RNA-editing candidates, primarily targeting cardiometabolic diseases.

AATD is a rare genetic disorder caused by mutations in the SERPINA1 gene, which encodes the AAT protein. Under normal circumstances, AAT is produced in the liver and transported to the lungs, where it regulates enzyme activity to prevent tissue damage. In patients with AATD, mutations can prevent AAT from exiting the liver, leading to toxic protein accumulation that damages the liver while also depriving the lungs of necessary protection. This can result in progressive lung disease, liver dysfunction, and symptoms such as shortness of breath, fatigue, and jaundice.

The AATD treatment landscape is becoming increasingly competitive as multiple biotechs advance RNA-editing candidates. Korro Bio is investigating its candidate KRRO-110 in the Phase I/IIa REWRITE clinical trial (NCT06677307), with interim data expected in H2 2025. The company announced last month that the dosing of the first two cohorts had been completed, and the trial is expected to conclude next year. Wave Life Sciences is developing WVE-006, which demonstrated targeted RNA editing in the first two patients treated in the Phase Ib/IIa RestorAATion-2 clinical trial (NCT06405633).

The growing interest in RNA editing has also drawn investment from major pharmaceutical companies. In November 2023, Roche expanded its partnership to develop a one-time RNA editing therapy using ShapeTX’s AI-powered platform for an undisclosed disease. In September 2024, Novo Nordisk and Korro Bio announced a collaboration leveraging Korro’s OPERA platform to enable oligonucleotide-directed RNA edits for two undisclosed targets, initially focused on cardiometabolic diseases. The deal included up to $530m in upfront, development, and commercial milestone payments, along with tiered royalties and R&D funding.

Not all genetic medicine approaches for AATD have progressed as planned. In January 2025, Intellia Therapeutics discontinued the development of its CRISPR-based gene therapy NTLA-3001, which was intended to correct the SERPINA1 mutation at the DNA level. Preparations for the Phase I/II trial were halted, along with other early-stage programmes, signalling a shift in the company’s pipeline priorities.

With fresh funding and a CTA planned for later this year, AIRNA is positioning itself within the growing RNA editing field.

Forbion managing partner Dirk Kersten said: “AIRNA’s innovative approach to RNA editing has the distinctive potential to improve health across large populations by introducing healthy genetic variants for many conditions. We are excited to support the expansion of AIRNA’s pipeline of life-changing medicines and the advancement of AIR-001 into the clinic.”