The study is a prospective, double arm, non-randomized, open label pilot trial, designed to study the safety, feasibility and preliminary efficacy of a medical device, the NovoTTF-100L concomitant with gemcitabine or concomitant with gemcitabine plus nab-paclitaxel, for front-line therapy of pancreatic adenocarcinoma. The device is an experimental, portable, battery operated device for chronic administration of alternating electric fields (termed TTFields or TTF) to the region of the malignant tumor, by means of surface, insulated electrode arrays.