REDWOOD CITY, Calif.—OncoMed Pharmaceuticals Inc., a clinical-stage company developing novel therapeutics that target cancer stem cells (CSCs), or tumor-initiating cells, has announced that the U.S. Food and Drug Administration’s Office of Orphan Products Development (OOPD) has granted Orphan Drug designation to tarextumab (anti-Notch 2/3, OMP-59R5) for the treatment of both pancreatic cancer and small cell lung cancer.
“We are excited to receive two separate orphan drug designations for tarextumab for the treatment of pancreatic and small cell lung cancer,” said Paul J. Hastings, OncoMed’s chairman and CEO. “OncoMed is enrolling patients in two randomized Phase 2 clinical trials of tarextumab in pancreatic and small cell lung cancer, and we recently reported promising safety and early efficacy data from our Phase 1b studies in these indications.”
Tarextumab is a fully human monoclonal antibody that targets the Notch2 and Notch3 receptors. Preclinical studies have suggested that tarextumab exhibits two mechanisms of action: (1) by downregulating Notch pathway signaling, tarextumab has anticancer stem cell activity and (2) tarextumab affects pericytes, impacting the stromal and tumor microenvironment. Tarextumab is currently being studied in two randomized Phase 2 clinical trials. The ALPINE study is assessing tarextumab with Abraxane (albumin bound) plus gemcitabine in first-line advanced pancreatic cancer patients. The PINNACLE study is testing tarextumab in combination with etoposide and cisplatin and etoposide and carboplatin in first-line extensive-stage small cell lung cancer patients.
“Tumor Notch3 gene expression is estimated to be elevated in approximately 70 percent of pancreatic cancer patients, and it is thought to be an indicator of poor prognosis and chemotherapy resistance,” noted Dr. Jakob Dupont, OncoMed’s chief medical officer. “The data suggesting that the biomarker-positive patients may have improved response rates and survival with tarextumab treatment are supportive of the Phase 2 design of the ALPINE study, where tarextumab’s impact on efficacy of all patients enrolled as well as the biomarker positive patients will be assessed. The Notch3 predictive biomarker may enable us to identify those patients that would gain the greatest benefit from tarextumab treatment.”
“Pancreatic cancer remains among the most challenging cancers in spite of recent treatment advances. The Phase 1b tarextumab data confirm safety and early signals of efficacy observed in earlier-stage studies,” said Dr. Eileen O’Reilly, associate director of clinical research for Memorial Sloan Kettering Cancer Center and a principal investigator of ALPINE. “Further exploration of tarextumab’s potential as a new treatment option for pancreatic cancer patients is warranted and ongoing in the randomized Phase 2 portion of the study. The trial will evaluate the addition of tarextumab in a frontline untreated pancreas cancer population and in specific biomarker-selected subsets.”
According to the American Cancer Society, there are approximately 46,000 new cases of pancreatic cancer each year in the United States. The majority of patients with pancreatic cancer are diagnosed after their cancer has spread locally and/or metastasized to distant organs. Rates of pancreatic cancer have been increasing over the past 10 years, and it is now the fourth-leading cause of cancer-related deaths. The average life expectancy after the diagnosis of metastatic pancreatic cancer is less than one year.
Small cell lung cancer was estimated to make up about 10 to 15 percent of the 224,210 newly diagnosed lung cancer cases and the 159,260 deaths estimated to occur in the United States in 2014. It tends to grow and spread quickly and is typically not discovered until it has metastasized to other parts of the body. In spite of a high sensitivity to chemotherapy and remission rates of up to 80 percent following initial treatment, the median overall survival is less than one year for patients with extensive stage disease.
Tarextumab is part of OncoMed’s collaboration with GlaxoSmithKline, which has an option to obtain an exclusive license to tarextumab through completion of the proof-of-concept Phase 2 trials.