# Plexium

Source: https://onco.cc/companies/plexium/  
OnCo record `plexium` (Company). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Plexium makes single-piece pills that make cancer cells destroy specific proteins. Its lead drug removes a protein called SMARCA2 in tumours that have lost its partner SMARCA4, and is in an early human trial.

## Summary

Plexium is a San Diego clinical-stage targeted protein degradation company that rationally designs monovalent direct degraders and molecular glues using its DELTA Discovery platform. PLX-61639 is an oral SMARCA2-selective direct degrader using a tissue-restricted E3 ligase, in a phase 1 trial in SMARCA4-mutant advanced solid tumours, exploiting SMARCA2/SMARCA4 synthetic lethality. PLX-4545 is an oral cereblon-based IKZF2 molecular glue degrader intended to convert regulatory T cells into effector-like cells and improve checkpoint inhibitor responses; it has completed a healthy-volunteer study. PLX-66140 is a preclinical CDK2 glue degrader for ER-positive/HER2-negative breast cancer and CCNE1-amplified tumours. Investors shown on the company site include The Column Group, TCG X, SoftBank, DCVC Bio, BVF Partners and Lux Capital; a Form D filed in August 2025 reports 60.1 million US dollars sold.

## Fields

- Kind: Company
- Last checked: 2026-09-10
- HQ: San Diego, CA
- Type: biotech
- Website: https://plexium.com/

## Notes

- Founding year not sourced.

## Sources

- Official website: https://plexium.com/
- Pipeline: https://plexium.com/pipeline/
- Clinical trials: https://plexium.com/clinical-trials/
- Form D (August 2025): https://www.sec.gov/Archives/edgar/data/2082715/000208271525000001/primary_doc.xml

## Connected records

- cancers: [HR-positive / HER2-negative breast cancer](https://onco.cc/cancers/breast-hr-positive/)
- fronts: [Targeted Therapy](https://onco.cc/fronts/targeted-therapy/)
- technologies: [PROTACs & molecular glues (targeted protein degradation)](https://onco.cc/technologies/protac-degrader/), [Synthetic lethality approaches](https://onco.cc/technologies/synthetic-lethality-approaches/)

---
JSON: https://onco.cc/api/v1/entities/plexium.json