ACELYRIN
The business, the turning points, and the decisions behind them.
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Sections to complete：02 · 05
01 / WHAT IT BUILT
What the company did
A biopharmaceutical business acquiring and developing therapeutic programs for commercialization.
02 / FAILURE REASONS
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03 / EVENT HISTORY
Events in the structured record
- Launched
ACELYRIN is launched as a venture-backed immunology biopharma company, built on the model of in-licensing promising immunology assets and advancing them toward commercialization.
- $621M IPO; izokibep setback
ACELYRIN completes a $621 million IPO, the biotech sector's biggest of 2023. Its lead asset izokibep, an IL-17A blocker, suffers a Phase IIb/III disappointment in September 2023.
- izokibep abandoned
After izokibep fails a Phase IIb/III study in uveitis in December 2024, Acelyrin discontinues the drug and returns it to former partner Affibody; the company lays off a third of its workforce and shifts focus to its anti-IGF-1R antibody lonigutamab for thyroid eye disease.
- Merger with Alumis
ACELYRIN rejects an unsolicited buyout offer from Concentra Biosciences and completes its all-stock merger with Alumis on May 21, 2025; the combined company operates under the Alumis name with about $737 million in cash and a combined pipeline led by ESK-001 and lonigutamab.
04 / CONTEMPORARY REBUILD ASSESSMENT
Difficulty of rebuilding this project today
Material for this section is being gathered and checked. It will appear here once ready.
Overall assessment: Not completed
05 / CAUSAL CHAIN / AFTERMATH
Material for this section is being gathered and checked. It will appear here once ready.