A prospective, multinational, multi-center, phase 2, randomized, controlled, open-label study evaluating the efficacy, safety, tolerability and pharmacokinetics of sig12d-loder in the treatment of patients with unresectable locally advanced pancreatic cancer when used in conjunction with standard chemotherapy (gemcitabine+nab-paclitaxel) versus chemotherapy (gemcitabine+nab-paclitaxel) alone