# PLX-61639

Source: https://onco.cc/drugs/plx-61639/  
OnCo record `plx-61639` (Treatment). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

PLX-61639 is an experimental oral monovalent direct protein degrader from Plexium, in phase 1 trials for SMARCA4-mutant locally advanced or metastatic solid tumours, non-small cell lung cancer and oesophageal and gastric cancers.

## Summary

PLX-61639 is an oral monovalent direct protein degrader from Plexium. An oral SMARCA2-selective degrader that uses a tissue-restricted E3 ligase; tumours that have lost SMARCA4 depend on SMARCA2, so removing it is synthetically lethal for them. Its furthest stage is phase 1, for SMARCA4-mutant locally advanced or metastatic solid tumours, non-small cell lung cancer and oesophageal and gastric cancers. ClinicalTrials.gov registers it in one study linked below. First-in-human phase 1 recruiting (NCT07284186). Whether it works in people has not been established unless a trial below reports it.

## Fields

- Kind: Treatment
- Status: phase-1
- Last checked: 2026-11-03
- Tags: pipeline; ctgov-ingest
- Code: PLX-61639
- Modality: Oral monovalent direct protein degrader
- Mechanism: An oral SMARCA2-selective degrader that uses a tissue-restricted E3 ligase; tumours that have lost SMARCA4 depend on SMARCA2, so removing it is synthetically lethal for them.

## Sources

- Plexium: plexium.com: https://plexium.com/pipeline/
- Plexium: plexium.com: https://plexium.com/clinical-trials/
- Plexium: clinicaltrials.gov: https://clinicaltrials.gov/study/NCT07284186
- ClinicalTrials.gov: trials of PLX-61639: https://clinicaltrials.gov/search?intr=PLX-61639

## Connected records

- cancers: [Gastric & gastro-oesophageal junction cancer](https://onco.cc/cancers/gastric/), [Metastatic cancer (cancer that has spread)](https://onco.cc/cancers/metastatic-cancer/), [Non-small-cell lung cancer](https://onco.cc/cancers/nsclc/)
- targets: [SMARCA2](https://onco.cc/targets/smarca2/)
- companies: [Plexium](https://onco.cc/companies/plexium/)
- trials: [First-in-Human Study of PLX-61639 in Locally Advanced or Metastatic Solid Tumors](https://onco.cc/trials/nct07284186/)

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