NAPA is a first-in-class cancer stemness inhibitor that targets STAT3, with promising activity in early trials.
Pts with ACRC who had failed all available standard therapy were randomized 1:1 to NAPA 480mg po q12h or PBO. Primary endpoint was overall survival (OS). Pre-specified biomarker analyses included pSTAT3 positivity by IHC in archival tissue based on nuclear staining of cancer cells >5% and stroma ≥2+. The study, designed to enrol 650 pts, was stopped after a futility analysis on disease control rate (DCR) in the first 96 pts. Analyses included Intent-to-treat (ITT) and exploratory Pre-defined Minimum Effective Treatment (pts who received ≥50% total daily dose for ≥6.4 weeks).
282 pts were randomized (138 NAPA, 144 PBO) from 04/2013 - 05/2014 when the trial was unblinded, accrual closed, and protocol treatment stopped after the futility analysis. Pts were median age = 64 (32 to 85); male = 65%; ECOG 0:1 (%) =28:72; >4 prior regimens = 98%; prior anti-VEGF = 89%; KRAS WT = 52%. No significant difference was observed in OS, progression free survival (PFS) or DCR between NAPA and PBO in the ITT analysis. AE more frequent with NAPA included: any grade diarrhea (88 vs 32%), nausea (63 vs 47%), and anorexia (56 vs 46%), all p
In this trial, NAPA monotherapy did not improve OS or PFS in unselected ACRC. While pSTAT3 positivity was a poor prognostic factor in untreated pts, NAPA treatment in pts with positive pSTAT3 significantly improved OS.
Clinical trial identification
Legal entity responsible for the study
Canadian Cancer Trials Group (CCTG) at Queens University in Kingston, ON, Canada
Canadian Cancer Society Research Institute (CCSRI) with funding support from Boston Biomedical Inc.
D.J. Jonker: Co-investigator on trials sponsored by Boston Biomedical Incorporated. No direct or indirect financial or other gain. No personal conflict. L. Nott: No conflict of interest pertaining to this research. Member on advisory committees for Roche and MSD. T. Yoshino: No conflict of interest relevant to this research. Has received research funding from GlaxoSmithKline K.K., and Boehringer Ingelheim GmbH. J. Zalcberg: No relevant conflicts for this research. Research and Travel Support Bayer (Stivarga) M.M. Vickers: No relevant conflicts for this research. Advisory Boards for Ipsen, Celgene, Amgen. Y. Gao: Employee, Boston Biomedical Incorporated T. Esaki: Research Funding; Sumitomo Dainippon Pharma. M. Hitron, C. Li: Employee, Boston Biomedical Incorporated. All other authors have declared no conflicts of interest.