Diagonal Therapeutics

Diagonal Therapeutics is a Watertown, Massachusetts clinical-stage biotechnology company founded in 2022 by CEO Alex Lugovskoy in partnership with Atlas Venture, developing "clustering" agonist antibodies that switch broken signaling pathways back on rather than inhibiting them. Its DIAGONAL product engine pairs computational epitope filtering with experimental screening — generating roughly 200,000 candidate antibody sequences per target, clustering them by predicted shape, binning by receptor complementarity and assembling multispecific antibodies from those bins — to make agonist antibody discovery tractable. The lead program, DIAG723, is a first-in-class ALK1:BMPRII clustering agonist antibody that restores ALK1 signaling; it holds US FDA and EMA orphan drug designation for hereditary hemorrhagic telangiectasia (HHT) and entered the Phase 1/2 DIAMOND trial (NCT07623525), with a first patient dosed in July 2026, alongside preclinical work in pulmonary arterial hypertension. The pipeline extends into hematology, hepatology, nephrology and cardiovascular disease. The company has raised roughly USD 255 million across a USD 128 million Series A (April 2024, co-led by BVF Partners and Atlas Venture) and an oversubscribed USD 125 million Series B (January 2026, co-led by Sanofi Ventures and Janus Henderson Investors). Diagonal is a therapeutics developer rather than a software vendor: it operates a Next.js marketing site backed by a Sanity CMS, and publishes no developer portal, no API documentation and no machine-readable API contract of any kind.

Diagonal Therapeutics is profiled on the APIs.io network. Tagged areas include Company, Biotechnology, Therapeutics, Antibodies, and Drug Discovery.

Diagonal Therapeutics’ developer surface includes engineering blog, support, and 12 more developer resources.

🌐 Visit website 📡 Source on GitHub

13.1/100 emerging ▬ flat Agent 0/100 human only Full breakdown ↓
scored 2026-08-17 · rubric v0.11.0

0 APIs

CompanyBiotechnologyTherapeuticsAntibodiesDrug DiscoveryRare DiseaseClinical TrialsLife SciencesPharmaceuticalsUnited States

Kin Score

Kin Score How this is scored →
scored 2026-08-17 · rubric v0.11.0

Composite quality — 13.1/100 · emerging

Contract Quality 0.0 / 21

Developer Ergonomics 1.1 / 17

Commercial Clarity 3.6 / 17

Operational Transparency 0.0 / 11

Governance 0.0 / 10

Discoverability 4.9 / 9

Regulatory Posture 3.6 / 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/diagonal-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 →

Agent Surfaces 2

MCP servers, agent skills, and machine-readable catalogs

WellKnown

WellKnown

LLMsTxt

LLMsTxt

Design & Contract 1

Pagination, idempotency, versioning, errors, and events

Conformance

Conformance

Build 1

SDKs, sample code, and the tooling you integrate with

Packages

Packages

Access & Security 1

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Operate 1

Status, limits, changes, and where to get help

Support

Support

Commercial 2

Pricing, plans, and the legal terms of use

PrivacyPolicy

PrivacyPolicy

TermsOfService

TermsOfService

Company 5

The organization behind the API

Website

Website

Blog

Blog

LinkedIn

Careers

Careers

Crunchbase

Crunchbase

Other 1

Properties that don't map to a standard resource type

SecondaryMarket

SecondaryMarket

Source (apis.yml)

aid: diagonal-therapeutics
name: Diagonal Therapeutics
description: 'Diagonal Therapeutics is a Watertown, Massachusetts clinical-stage biotechnology company founded in 2022 by
  CEO Alex Lugovskoy in partnership with Atlas Venture, developing "clustering" agonist antibodies that switch broken signaling
  pathways back on rather than inhibiting them. Its DIAGONAL product engine pairs computational epitope filtering with experimental
  screening — generating roughly 200,000 candidate antibody sequences per target, clustering them by predicted shape, binning
  by receptor complementarity and assembling multispecific antibodies from those bins — to make agonist antibody discovery
  tractable. The lead program, DIAG723, is a first-in-class ALK1:BMPRII clustering agonist antibody that restores ALK1 signaling;
  it holds US FDA and EMA orphan drug designation for hereditary hemorrhagic telangiectasia (HHT) and entered the Phase 1/2
  DIAMOND trial (NCT07623525), with a first patient dosed in July 2026, alongside preclinical work in pulmonary arterial hypertension.
  The pipeline extends into hematology, hepatology, nephrology and cardiovascular disease. The company has raised roughly
  USD 255 million across a USD 128 million Series A (April 2024, co-led by BVF Partners and Atlas Venture) and an oversubscribed
  USD 125 million Series B (January 2026, co-led by Sanofi Ventures and Janus Henderson Investors). Diagonal is a therapeutics
  developer rather than a software vendor: it operates a Next.js marketing site backed by a Sanity CMS, and publishes no developer
  portal, no API documentation and no machine-readable API contract of any kind.'
image: https://diagonaltx.com/images/diamond-white-logo.webp
url: https://raw.githubusercontent.com/api-evangelist/diagonal-therapeutics/refs/heads/main/apis.yml
x-type: company
x-source: harvest:secondary-market
x-tier: stub
x-tier-reason: harvest
x-enrichment:
  date: '2026-08-04'
  status: minimal
  artifacts_added: 5
  pass: local-v1
specificationVersion: '0.20'
created: '2026-08-04'
modified: '2026-08-04'
tags:
- Company
- Biotechnology
- Therapeutics
- Antibodies
- Drug Discovery
- Rare Disease
- Clinical Trials
- Life Sciences
- Pharmaceuticals
- United States
apis: []
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: Website
  url: https://diagonaltx.com/
- type: Blog
  url: https://diagonaltx.com/#latest-news
- type: Support
  url: mailto:info@diagonaltx.com
- type: PrivacyPolicy
  url: https://diagonaltx.com/legal-documents/privacy-policy
- type: TermsOfService
  url: https://diagonaltx.com/legal-documents/terms-of-service
- type: LinkedIn
  url: https://www.linkedin.com/company/diagonal-therapeutics/
- type: Careers
  url: https://www.linkedin.com/company/diagonal-therapeutics/jobs/
- type: Crunchbase
  url: https://www.crunchbase.com/organization/diagonal-therapeutics
- type: SecondaryMarket
  url: https://forgeglobal.com/diagonal-therapeutics_stock/
- type: DomainSecurity
  url: security/diagonal-therapeutics-domain-security.yml
- type: WellKnown
  url: well-known/diagonal-therapeutics-well-known.yml
- type: Packages
  url: packages/diagonal-therapeutics-packages.yml
- type: Conformance
  url: conformance/diagonal-therapeutics-conformance.yml
- type: LLMsTxt
  url: llms/diagonal-therapeutics-llms.txt