Leyden Labs buys RIGImmune, unveils Phase 1 nasal antiviral data
What's the deal? Dutch biotech Leyden Labs has acquired US-based RIGImmuneDealroom has a profile for this one. Try Dealroom →, the developer of intranasal drug RIG-101, and disclosed positive Phase 1 results for the candidate. Financial terms were undisclosed, though the share purchase agreement is dated March 20, 2026.
What's the endgame? The acquisition pushes Leyden Labs beyond the broadly protective nasal antibodies at the core of its pipeline. RIGImmune's approach switches on the airway's own antiviral defenses — a second route to mucosal protection.
How it works: RIG-101 belongs to a class of oligonucleotides called stem-loop RNA therapeutics, designed to activate RIG-I, an intracellular sensor of viral RNA that triggers innate antiviral responses. The drug is delivered to the respiratory mucosa via NEED, RIGImmune's non-lipid nanoparticle platform.
The data: Leyden Labs said RIG-101 was safe and well tolerated across all tested doses in healthy volunteers and asthma patients, including after daily dosing for up to seven days. In asthma patients, treatment induced type I and type III interferons, consistent with its mechanism. The company withheld participant numbers, adverse-event rates, and quantitative biomarker results.
The next test is more meaningful: the trial's Part B will expose adults with asthma to rhinovirus RV-A16 to see whether the drug protects them. The Phase 1/2 program targets 82 participants at two UK sites.
The key hire: Susan Sobolov, former president and chief operating officer of RIGImmune, is now chief technology officer at Leyden Labs — a sign the acquired technology could take a larger role in the company's development strategy.
Following the money: Alembic PharmaceuticalsDealroom has a profile for this one. Try Dealroom →, an early RIGImmune investor, said in its annual report that it received 994,615 preferred shares and 1,032,592 common shares in Leyden Labs, valued at $6.68 million, plus milestone-linked payments. That figure is not the full price but points to a stock-based deal rather than cash. Alembic had backed RIGImmune since 2021, when its initial investment gave it a 19.97% post-money stake.
Backstory: RIGImmune was founded in 2020 by Yale professors Anna Marie Pyle and Akiko Iwasaki. In 2022, it acquired UK drug-delivery company SubIntroDealroom has a profile for this one. Try Dealroom → to build its NEED platform, later securing a Yale license and backing from the Gates FoundationDealroom has a profile for this one. Try Dealroom →.
Why now? The deal landed during heavy fundraising for Leyden Labs, which added €40 million in June from investors including the EIC Fund, Invest-NLDealroom has a profile for this one. Try Dealroom →, and the Gates Foundation.
The signal: Leyden Labs is betting that pairing broad nasal antibodies with innate immune activation can widen its shot at stopping respiratory viruses at the point of entry. The stock-based structure and the CTO appointment suggest RIGImmune's platform is now central, not peripheral, to that plan.
Read more: european-biotechnology.com
Image credit: Generated with Gemini
