aid: acelyrin
name: ACELYRIN, Inc.
description: 'ACELYRIN, Inc. (Nasdaq: SLRN) was a late-stage clinical biopharmaceutical
  company headquartered in Agoura Hills, California, focused on accelerating the development
  and commercialization of medicines in immunology. Its lead candidates were izokibep,
  an anti-IL-17A small protein therapeutic, and lonigutamab, a humanized IgG1 monoclonal
  antibody against IGF-1R. It completed a $540M IPO in May 2023, and on May 21, 2025
  it merged with a subsidiary of Alumis, Inc. and survives as a wholly owned Alumis
  subsidiary. Its corporate domain acelyrin.com now 301-redirects to alumis.com. The
  company is a drug developer, not a software vendor: it published no developer program,
  public API, SDK, webhook surface, or machine-readable specification, and no GitHub
  organization exists under the ACELYRIN name.'
url: https://raw.githubusercontent.com/api-evangelist/acelyrin/refs/heads/main/apis.yml
x-type: company
x-source: harvest:secondary-market
x-tier: stub
x-tier-reason: harvest
x-parent-company: alumis
x-secondary-market-listing: https://forgeglobal.com/acelyrin_stock/
specificationVersion: '0.20'
created: '2026-09-06'
modified: '2026-09-06'
tags:
- Company
- Biopharmaceutical
- Biotechnology
- Pharmaceuticals
- Immunology
- Clinical Trials
- Healthcare
- Acquired
apis: []
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: DomainSecurity
  url: security/acelyrin-domain-security.yml
- type: Website
  url: https://acelyrin.com/
x-enrichment:
  date: '2026-09-06'
  status: minimal
  artifacts_added: 2
  pass: local-v3
x-coverage:
  state: none
  reason: defunct
  detail: >-
    ACELYRIN was absorbed into Alumis, Inc. on 2025-05-21 as a wholly owned subsidiary
    and its corporate domain acelyrin.com now 301-redirects to www.alumis.com, so the
    only surviving surface belongs to the acquirer; the company was a clinical-stage
    drug developer that never published a developer portal, API, or GitHub organization.
  evidence:
  - url: https://acelyrin.com/
    status: 301
  - url: https://www.alumis.com/
    status: 200
  - url: https://acelyrin.com/.well-known/api-catalog
    status: 404
  - url: https://acelyrin.com/openapi.json
    status: 404
  - url: https://api.github.com/orgs/acelyrin
    status: 404
  checked: '2026-09-06'