# 858 Therapeutics

**Canonical:** https://apis.io/providers/858-therapeutics/  
**Website:** https://8five8tx.com/  
**APIs profiled:** 0

858 Therapeutics is a clinical-stage biotechnology company based in San Diego, California, developing first-in-class and best-in-class small-molecule therapies that target tumor dependencies in DNA damage response (DDR) pathways. Its lead program, ETX-19477, is an oral, potent, and selective PARG (poly(ADP-ribose) glycohydrolase) inhibitor being evaluated in a Phase 1/2 study for patients with advanced solid tumors, exploiting cancer-cell vulnerabilities tied to replication stress and defects in replication-fork protection. The company was surfaced as a portfolio company of Insight Partners and added to the API Evangelist network. As a clinical-stage therapeutics company it publishes a corporate and scientific web presence but no public developer, API, or documentation surface, so API artifacts are not applicable.

## Kin Score — 4.7 / 100 (minimal)

Scored 2026-08-20 under rubric 0.12.0. Trend: flat (+0.0 from 4.7).

| Facet | Score |
|---|---|
| Discoverability | 50.0 |
| Contract Quality | 0.0 |
| Governance | 0.0 |
| Contract Governance | 0.0 |
| Operational Transparency | 0.0 |
| Developer Ergonomics | 7.1 |
| Commercial Clarity | 0.0 |
| Access Clarity | 0.0 |

Regulatory layer — **Health**: 7.5 (matched via tags).

## Agent readiness — 0.0 (human-only)

| Dimension | Value |
|---|---|
| Spec Presence | no |
| Agentic Access | no |
| Reversibility Documented | no |
| MCP Server | no |
| Auth Clarity | no |
| Idempotency | no |
| Error Semantics | no |
| OpenAPI Examples | no |
| Rate Limit Signal | no |
| Event Surface Described | no |
| Agent Skills | no |
| Well Known Catalog | no |
| Consent Identity | no |
| Agent Card | no |
| Dry Run Mode | no |

## Access

Unknown — onboarding: unknown, pricing: unknown, trial: no (confidence: low).

## Security (1)

- **858 Therapeutics Domain Security** — TLSv1.3 · DMARC

## Tags

Company, Biotech, Therapeutics, Oncology, Precision Medicine, Drug Discovery, DNA Damage Response, Clinical Stage, Pharmaceuticals

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Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/providers/858-therapeutics/). Scores are computed from the provider's own public artifacts under a published rubric.