IL-33 inhibitor struggles (2019-2026)
Multiple companies pursued IL-33 inhibitors for respiratory disease with limited success, leading investors and researchers to question whether the target was viable. Roche's astegolimab remains in Phase III.
Several programs stalled or failed to meet endpoints.
IL-33 became seen as a risky target for respiratory biologics.
Tozorakimab's Phase III success suggests its dual-pathway mechanism may overcome the limitations of earlier IL-33 drugs.
