Napabucasin Provides No Added Benefit in Metastatic Pancreatic Cancer

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 (ClinicalTrials.gov 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.

Reference

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