We will be conducting a Phase II study investigating PEGPH20 in combination with gemcitabine and nab-paclitaxel in patients with borderline resectable pancreatic ductal adenocarcinoma (PDAC) at the Helen Diller Family Comprehensive Cancer Center at University of California, San Francisco (UCSF). There are multiple definitions of borderline resectable PDAC including the MD Anderson definition and the criteria developed during the Consensus Conference sponsored by the American Hepato-Pancreato-Biliary Association, Society of Surgical Oncology, and Society for Surgery of the Alimentary Tract. Borderline resectable PDAC cases will be identified per the definition developed in the currently running inter-group pilot trial for borderline resectable pancreatic cancer (NCT01821612). Per this trial, borderline resectable PDAC is defined as "presence of any one or more of the following on CT:
* An interface between the primary tumor and the superior mesenteric vein or portal vein (SMV-PV) measuring ≥ 180° of the circumference of the vessel wall
* Short-segment occlusion of the SMV-PV with normal vein above and below the level of obstruction that is amenable to resection and venous reconstruction
* Short segment interface (of any degree) between tumor and hepatic artery with normal artery proximal and distal to the interface that is amenable to resection and reconstruction.
* An interface between the tumor, and Superior mesenteric artery (SMA) measuring \< 180º of the circumference of the vessel wall.
This trial will be conducted in two parts. In Part I, pre-treatment endoscopic ultrasound (EUS)-guided core biopsies of the pancreatic tumor, CA 19-9 levels and functional MRIs including Dynamic contrast-enhanced (DCE)-MRI and Diffusion-weighted magnetic resonance imaging (DWI-MRI) will be obtained for the first fifteen patients enrolled. After a 1-week run-in period with PEGPH20 on days 1 and 4, patients will have repeat EUS-guided core biopsies, functional MRI, CA 19-9 level and baseline CT chest, abdomen and pelvis. Subsequently, patients will be started on treatment with PEGPH20, gemcitabine and nab-paclitaxel given weekly for 3 weeks, every 28 days. To evaluate the disease response to treatment, CA 19-9 levels will be checked monthly and restaging CT chest, abdomen and pelvis will be obtained every 8 weeks. If there is disease progression at any point in the study, patients will be taken off of study and alternative treatments will be offered. At the completion of 4 cycles of therapy, restaging CT scans will be obtained to determine resectability. If the patients are found to have resectable disease, an additional functional MRI will be obtained to evaluate the PDAC stroma. If the patients are able to have successful surgeries, tissue analyses will be performed on the resected pancreatic tumor. These patients will then proceed to get 2 cycles of adjuvant chemotherapy with gemcitabine and nab-paclitaxel. If the patients are deemed to be surgical candidates but are found to have unresectable disease in the operating room, an intraoperative core biopsy of the pancreatic tumor will be obtained for tissue analyses. At the time of initiation of therapy with PEGPH20, patients will be started on prophylactic dose of enoxaparin 1 mg/kg subcutaneous daily. This will be continued throughout the study participation.
In Part II, an additional 21 patients will be enrolled, and will begin neoadjuvant therapy with PEGPH20, gemcitabine and nab-paclitaxel without the 1 week run-in of PEGPH20-only or the pre- and post-run-in EUS-guided biopsies.