Napabucasin Provides No Added Benefit in Metastatic Pancreatic Cancer

X-ray of pancreas
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The phase 3 CanStem111P study was terminated early due to futility.

The following article features coverage from the European Society of Medical Oncology (ESMO) Congress 2021. Click here to read more of MPR‘s conference coverage.

Adding napabucasin to frontline treatment with nab-paclitaxel and gemcitabine does not improve response or survival outcomes in patients with metastatic pancreatic adenocarcinoma, according to results of a phase 3 trial presented in a poster at the European Society for Medical Oncology (ESMO) Congress 2021.

The CanStem111P study ( Identifier: NCT02993731) included 1134 adults with treatment-naive, metastatic pancreatic adenocarcinoma who were randomly assigned to receive nab-paclitaxel and gemcitabine (569 patients) or napabucasin plus nab-paclitaxel and gemcitabine (565 patients).

Baseline characteristics were generally well balanced between the treatment arms, according to the researchers. In both arms, patients received a median of 6 treatment cycles. The trial was terminated early due to futility, based on results of the interim analysis. At the time of database lock, 74.5% of patients in the napabucasin arm and 71.0% of those in the control arm had died.    

Efficacy outcomes were similar between the treatment arms. The overall response rate was 43.2% in the napabucasin arm and 42.9% in the control arm. The complete response rates were 0.7% and 1.1%, respectively.

The median progression-free survival was 6.7 months in the napabucasin arm and 6.1 months in the control arm (hazard ratio [HR], 1.04; 95% CI, 0.91-1.19; P =.71). The median overall survival was 11.4 months and 11.7 months, respectively (HR, 1.07; 95% CI, 0.93-1.23; P =.84).

Nearly all patients in both treatment arms experienced an adverse event (AE). The most common of these (in the napabucasin and control arms, respectively) were diarrhea (73.1% vs 38.9%), nausea (58.6% vs 46.1%), and anemia (54.5% vs 58.1%). Grade 3 or higher treatment-related AEs occurred in 85.4% of patients in the napabucasin arm and 83.9% of those in the control arm. Serious AEs were reported in 58.8% and 49.9%, respectively.

The researchers noted that nearly twice as many patients in the napabucasin arm as in the control arm experienced an AE resulting in death (11.1% vs 6.2%). However, a safety review suggested the imbalance was “not due to a safety signal.”

The researchers concluded that, although there were no response or survival improvements with napabucasin, these results “reinforce nab-paclitaxel plus gemcitabine as a backbone for novel therapeutic approaches” in this patient population.

Disclosures: This research was supported by Sumitomo Dainippon Pharma Oncology, Inc. Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.


Bekaii-Saab T, Okusaka T, Goldstein D, et al. Napabucasin + nab-paclitaxel with gemcitabine in patients (pts) with metastatic pancreatic adenocarcinoma (mPDAC): Results from the phase III CanStem111P study. Presented at: European Society of Medical Oncology (ESMO) Congress 2021; September 16-21, 2021. Abstract 1466P.

This article originally appeared on Cancer Therapy Advisor