MabVax Therapeutics Holdings, Inc. announced positive interim results from the company's ongoing Phase 1 trial evaluating MVT-5873 in combination with standard of care chemotherapy in patients newly diagnosed with pancreatic and other CA19-9 positive malignancies. At the dose tested, all six patients in the cohort had meaningful reductions in tumor volume by RECIST. In the Phase 1 study, MabVaxs MVT-5873, a fully human antibody, was given in combination with nab-paclitaxel and gemcitabine to patients newly diagnosed with CA19-9 positive pancreatic cancer. MVT-5873 at a dose of 0.125 mg/kg when added to first-line chemotherapy was generally well tolerated by all subjects. The Company reported that all six patients had measurable tumor reductions, with four patients meeting the criteria for partial response (PR) and two patients meeting the criteria for stable disease (SD). These results help confirm results reported from a group of patients treated earlier. Patient CA19-9 levels, which are a prognostic indicator of the disease state, were markedly reduced in all subjects with this combination therapy. The company plans to enroll additional patients at this dose to further explore safety and potential response. This Phase 1 clinical trial is an open-label, multi-center nonrandomized study evaluating the safety and recommended Phase 2 dose of MVT-5873 in combination with a standard of care chemotherapy in subjects with pancreatic and other CA19-9 positive malignancies. Secondary objectives include evaluating tumor response rate by RECIST 1.1, duration of response, and to determine pharmacokinetics. This study utilizes a conventional 3+3 design to identify the recommended Phase 2 dose. Dr. Eileen O'Reilly, Associate Director of the David M. Rubenstein Center for Pancreatic Cancer Research, attending physician, member at Memorial Sloan Kettering Cancer Center and Professor of Medicine at Weill Cornell Medical College is the lead investigator in the MVT-5873 Phase 1 clinical trial.