GSK plc is plunking down $1 billion cash to take over Aiolos Bio Inc., with the promise of as much as $400 million in regulatory milestone payments along with tiered royalties. The deal gives London-based GSK asthma candidate AIO-001, a phase II-ready, long-acting antibody that binds to the human thymic stromal lymphopoietin (TSLP) ligand to inhibit TSLP signaling and relieve inflammation. GSK said AIO-001 could redefine the standard of care in asthma via the prospect of dosing every six months.

With one of the higher series A rounds for 2023, the newly launched Aiolos Bio Inc. pulled in $245 million to advance its lead product, AIO-001, an anti-thymic stromal lymphopoietin monoclonal antibody set to enter a phase II trial for moderate to severe asthma.