A Trial of Cobicistat and Gemcitabine and Nab-Paclitaxel in Patients with Advanced Stage or Metastatic Pancreatic Ductal Adenocarcinoma

To explore the possibility to overcome CYP3A-mediated resistance to anticancer drugs in pancreatic cancer, we will investigate the pharmacokinetics, safety, tolerability, and efficacy of nanoparticle albumin-bound paclitaxel (nab-paclitaxel) in combination with gemcitabine and the CYP3A inhibitor cobicistat in a phase I proof-of-concept trial to determine the safety profile, the recommended dose of nab-paclitaxel in combination with gemcitabine and cobicistat, and to determine whether there is an early efficacy signal warranting a larger scale trial. The present trial is an open-label trial consisting of a dose-escalation part and an expansion part. The dose escalation part is designed to determine the safety, tolerability, and pharmacokinetics of nab-paclitaxel in combination with gemcitabine and cobicistat and will guide the dosing in the expansion part of the trial. The trial enrolls patients with unresectable locally advanced or metastatic pancreatic adenocarcinoma and adequate performance score (ECOG PS 0-2) who would usually receive gemcitabine and nab-paclitaxel according to standard of care. Primary endpoint for the phase I trial is the safety of the combination. Overall survival (OS), disease control rate (DCR), overall response rate (ORR), duration of response (DoR) and progression free survival (PFS) are secondary efficacy endpoints. Further secondary endpoints are tolerability, pharmacokinetics, pharmacodynamics, and pharmacogenomics.