Ensituximab

NEO-102 is a novel chimeric IgG1 monoclonal antibody which recognizes a variant form of MUC5AC expressed specifically by human pancreatic and colorectal tumors. Preclinical models have demonstrated encouraging signs of anti-tumor activity through antibody-dependent cell-mediated cytotoxicity.

This is a phase 1, dose-escalation trial of NEO-102 (Ensituximab) for patients with refractory pancreatic and colorectal cancer. The primary objective was to determine safety and tolerability of escalating doses of NEO-102. Secondary objectives were to assess pharmacokinetics, anti-tumor activity and biologic correlates. Patients whose tumors express NPC-1 antigen were eligible. Dose-escalation was performed in a 3 + 3 design at doses of 1.5, 2, 3 and 4 mg/kg.

A total of 19 patients (4 pancreatic and 15 colon cancer) were enrolled at participating institutions in the treatment phase. Most common treatment-related adverse events included anemia, fatigue, fevers, chills and flushing. There was no detectable hemolysis. Of twelve patients evaluable for disease response, the response rate at week 8 included 5 patients with stable disease and 8 patients with progressive disease (PD). Treatment-related grade 3/4 hyperbilirubinemia and anemia were observed at 4 mg/m2. Reversible hypoxia at 3 mg/kg was a dose-limiting toxicity. The maximum tolerated dose was established at 3 mg/kg. Of 74 patients who underwent tissue screening, positive NPC-1 expression was 47 % in colon and 59 % in pancreatic cancer.

Treatment with the NEO-102, in this first-in-human study, is well tolerated with a manageable safety profile. A maximum tolerated dose of 3 mg/kg has been established. Toxicity profile is typical for this therapeutic class and allows for combination with conventional cytotoxic therapies.

Metastatic pancreatic cancer continues to be a difficult disease to treat because of its aggressive nature, advanced stage at presentation and lack of treatment options. There is a need for the development of new agents directed against novel targets to improve outcomes for these patients. At the 2014 American Society of Clinical Oncology (ASCO) Gastrointestinal Cancers Symposium phase I/II trials provided information on three novel strategies for treating metastatic pancreatic cancer. Immunotherapy in the form of a vaccine (GVAX) followed with an immune stimulator (CRS-207) showed extended survival (Abstract #177). A monoclonal antibody (NEO-102) targeting MUC5AC also showed activity and was well tolerated (Abstract #243). A heat shock protein 90 (HSP90) inhibitor (ganetespib) showed modest effects but was well tolerated making it available for use with conventional chemotherapy (Abstract #297). The details of these presentations will be discussed.