Capstan Therapeutics

Capstan Therapeutics was a clinical-stage biotechnology company based in San Diego, California, developing in vivo cell engineering medicines built on a proprietary targeted lipid nanoparticle (tLNP) platform that delivers mRNA and other RNA payloads to specific cell types inside the body. Its lead candidate CPTX2309 is an anti-CD19 in vivo CAR-T therapy in Phase 1 for B cell-mediated autoimmune disease, intended to achieve deep B cell depletion without lymphodepleting chemotherapy. AbbVie completed its acquisition of Capstan on 19 August 2025 for up to $2.1 billion. The company's own domain now redirects to AbbVie and its DNS is served by AbbVie nameservers; it operates no developer program, public API, SDK, or machine-readable specification.

Capstan Therapeutics is profiled on the APIs.io network. Tagged areas include Company, Biotechnology, Pharmaceuticals, Cell Therapy, and Immunology.

🌐 Visit website 📡 Source on GitHub
3.9/100 minimal ▬ flat Agent 0/100 human only Full breakdown ↓
scored 2026-08-17 · rubric v0.11.0
0 APIs
CompanyBiotechnologyPharmaceuticalsCell TherapyImmunologyLife SciencesAcquired

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-08-17 · rubric v0.11.0
Composite quality — 3.9/100 · minimal
Contract Quality 0.0 / 21
Developer Ergonomics 0.0 / 17
Commercial Clarity 0.0 / 17
Operational Transparency 0.0 / 11
Governance 0.0 / 10
Discoverability 3.9 / 9
Regulatory Posture 0.0 / 15
Agent readiness — 0/100 · human only
Machine-Readable Contract 0 / 18
Agentic Access Contract 0 / 10
MCP Server 0 / 12
Machine-Readable Auth 0 / 10
Idempotency 0 / 9
Stable Error Semantics 0 / 8
Request/Response Examples 0 / 7
Rate-Limit Signaling 0 / 7
Typed Event Surface 0 / 6
Agent Skills 0 / 5
Well-Known Catalog 0 / 4
Consent & Bot Identity 0 / 3
A2A Agent Card 0 / 8
Dry-Run / Simulate Mode 0 / 4
Regulatory Posture applies to this provider. Its tags matched the Health regime, so Regulatory Posture carries 15 points of the composite. If this regime is wrong for your business, say so on your provider repo — the applicability map is public and we will correct it.
The six quality facets above are damped to 85 points between them, because the conditional facet above carries the other 15. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 85% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.
Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. This rating is computed from github.com/api-evangelist/capstan-therapeutics: open an issue to ask a question, or submit a pull request to add artifacts. Want it done for you? Prioritized profiling — $2,500 →

Resources

Company 1

The organization behind the API

Website
Website

Source (apis.yml)

apis.yml Raw ↑ 
aid: capstan-therapeutics
name: Capstan Therapeutics
description: Capstan Therapeutics was a clinical-stage biotechnology company based in San Diego, California, developing in
  vivo cell engineering medicines built on a proprietary targeted lipid nanoparticle (tLNP) platform that delivers mRNA and
  other RNA payloads to specific cell types inside the body. Its lead candidate CPTX2309 is an anti-CD19 in vivo CAR-T therapy
  in Phase 1 for B cell-mediated autoimmune disease, intended to achieve deep B cell depletion without lymphodepleting chemotherapy.
  AbbVie completed its acquisition of Capstan on 19 August 2025 for up to $2.1 billion. The company's own domain now redirects
  to AbbVie and its DNS is served by AbbVie nameservers; it operates no developer program, public API, SDK, or machine-readable
  specification.
url: https://raw.githubusercontent.com/api-evangelist/capstan-therapeutics/refs/heads/main/apis.yml
x-type: company
x-source: harvest:secondary-market
x-source-url: https://forgeglobal.com/capstan-therapeutics_stock/
x-tier: stub
x-tier-reason: harvest
specificationVersion: '0.20'
created: '2026-08-09'
modified: '2026-08-09'
tags:
- Company
- Biotechnology
- Pharmaceuticals
- Cell Therapy
- Immunology
- Life Sciences
- Acquired
apis: []
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: Website
  url: https://capstantx.com/
x-enrichment:
  date: '2026-08-09'
  status: nochange
  artifacts_added: 0
  pass: local-v1
x-coverage:
  state: none
  reason: defunct
  detail: 'Capstan''s own site is gone: capstantx.com 301s to www.abbvie.com/capstan-therapeutics.html and its nameservers
    are now ns1-4.abbviedns.com, following AbbVie''s completed acquisition on 19 August 2025 — the company was a clinical-stage
    biotech that never operated a developer program, GitHub org, or public API.'
  evidence:
  - url: https://capstantx.com/
    status: 301
  - url: https://www.capstantx.com/
    status: 301
  - url: https://capstantx.com/.well-known/agent-card.json
    status: 403
  - url: https://capstantx.com/openapi.json
    status: 403
  - url: https://api.github.com/orgs/capstantx
    status: 404
  checked: '2026-08-09'