# PTT-4256

Source: https://onco.cc/drugs/ptt-4256/  
OnCo record `ptt-4256` (Treatment). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

PTT-4256 is an experimental oral small molecule from Pathios Therapeutics, in phase 1 trials for advanced solid tumours.

## Summary

PTT-4256 is an oral small molecule from Pathios Therapeutics. An orally bioavailable, selective inhibitor of GPR65, an acid-sensing receptor on immune cells; the company's case is that the acidic tumour environment acts through GPR65 to switch immune cells into a suppressed, pro-tumour state. Its furthest stage is phase 1, for advanced solid tumours. ClinicalTrials.gov registers it in one study linked below. Phase 1/2 RAISIC-1 NCT06634849 recruiting (Australia). 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: PTT-4256
- Modality: Oral small molecule
- Mechanism: An orally bioavailable, selective inhibitor of GPR65, an acid-sensing receptor on immune cells; the company's case is that the acidic tumour environment acts through GPR65 to switch immune cells into a suppressed, pro-tumour state.

## Sources

- Pathios Therapeutics: pathios.com: https://pathios.com/
- Pathios Therapeutics: pathios.com: https://pathios.com/
- Pathios Therapeutics: clinicaltrials.gov: https://clinicaltrials.gov/api/v2/studies/NCT06634849
- ClinicalTrials.gov: trials of PTT-4256: https://clinicaltrials.gov/search?intr=PTT-4256

## Connected records

- cancers: [Metastatic cancer (cancer that has spread)](https://onco.cc/cancers/metastatic-cancer/)
- targets: [GPR65](https://onco.cc/targets/gpr65/)
- companies: [Pathios Therapeutics](https://onco.cc/companies/pathios-therapeutics/)
- trials: [An Open Label Dose Finding Study of PTT-4256 in Patients With Solid Tumours (RAISIC-1).](https://onco.cc/trials/nct06634849/)

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JSON: https://onco.cc/api/v1/entities/ptt-4256.json