# Napabucasin

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

## TL;DR

Napabucasin, an oral drug marketed as a cancer stemness inhibitor, was tested in 1,134 people with untreated metastatic pancreatic cancer on top of nab-paclitaxel and gemcitabine; survival was identical and the trial was stopped for futility.

## Summary

Napabucasin is bioactivated by NQO1 to generate reactive oxygen species and was developed as an inhibitor of STAT3-driven stemness. CanStem111P randomised 1,134 patients across 165 sites in 20 countries to napabucasin with nab-paclitaxel and gemcitabine or chemotherapy alone; median overall survival was 11.4 against 11.7 months (hazard ratio 1.07, 95 percent confidence interval 0.93 to 1.23), with no difference in the 382 patients whose tumours were positive for phosphorylated STAT3, and the trial was terminated for futility. Grade 3 or worse diarrhoea (11.6 against 4.9 percent) and abdominal pain (10.0 against 4.8 percent) were commoner with napabucasin. The trial remains the largest randomised dataset of nab-paclitaxel and gemcitabine and a reference control arm for first-line metastatic disease.

## Fields

- Kind: Treatment
- Status: negative
- Last checked: 2026-09-24
- Also known as: BBI-608; BBI608
- Code: BBI-608
- Modality: Oral small-molecule NQO1-bioactivated reactive oxygen species generator (STAT3 pathway inhibitor)
- Mechanism: NQO1-dependent redox cycling producing reactive oxygen species; reduces STAT3 phosphorylation and stemness gene expression in preclinical models.

## Sources

- Bekaii-Saab et al., CanStem111P (eClinicalMedicine 2023): https://doi.org/10.1016/j.eclinm.2023.101897
- ClinicalTrials.gov NCT02993731: https://clinicaltrials.gov/study/NCT02993731

## Connected records

- cancers: [Colorectal cancer](https://onco.cc/cancers/colorectal/), [Metastatic pancreatic ductal adenocarcinoma](https://onco.cc/cancers/metastatic-pdac/), [Pancreatic ductal adenocarcinoma](https://onco.cc/cancers/pancreatic/)
- targets: [STAT3](https://onco.cc/targets/stat3/)
- companies: [Sumitomo Pharma (Myovant)](https://onco.cc/companies/sumitomo-pharma/)
- terms: [Pancreatic cancer: the failed and stopped programmes and why](https://onco.cc/terms/pancreatic-failed-programmes/)
- trials: [CanStem111P](https://onco.cc/trials/canstem111p/)

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