Polaris Group's ADI-PEG 20 Shows Robust Clinical Activity in Malignant Plural Mesothelioma and NSCLC When Combined with Standard First Line Chemotherapy Regimen

Nov 11, 2015, 13:30 ET from Polaris Group

SAN DIEGO, Nov. 11, 2015 /PRNewswire/ -- Polaris Group announced today the preliminary results from an ongoing phase 1 study that tests combining its lead therapeutic ADI-PEG 20 (pegylated arginine deiminase) with the standard first-line chemotherapy (cisplatin + pemetrexed doublet) in malignant plural mesothelioma (MPM) and non-squamous non-small cell lung carcinoma (NSCLC).  The results were presented at the Molecular Targets and Cancer Therapeutics Conference in Boston on Saturday, November 7.  MPM and NSCLC patients with tumor cells deficient in the enzyme argininosuccinate synthetase (ASS1) enrolled in the study received standard dose cisplatin + pemetrexed, and increasing doses of ADI-PEG 20 treatment.  ASS1 plays an important role in the synthesis of the amino acid arginine, which is required for cell growth and function. Polaris Group believes that ASS1 deficiency in certain cancer cells requires these cells to obtain arginine from the circulation in order to survive.  ADI-PEG 20 is designed to deplete arginine in the circulation and cause cancer cells to die while leaving patients' normal cells unharmed.

Nine patients, five MPM and 4 NSCLC, were enrolled in the dose escalating cohorts.  No dose limiting toxicity has been observed.  Seven patients (77.8%) had a partial response (PR) and two patients had stable disease (SD) as best response (100% disease control rate). Two of the five MPM patients have sarcomatoid MPM, a histological subtype that has the worst prognosis among all MPM patients.  One of the two sarcomatoid MPM patients had a PR while the other had SD.  Currently the study is on-going in expansion cohorts.   

"We are excited by the robust clinical activity seen in the dose escalating cohorts in both cancers," said John Bomalaski, M.D., Executive Vice President, Medical Affairs, of Polaris Pharmaceuticals, Inc. "We look forward to confirming the promising results in the expansion cohorts."

About ADI-PEG 20

ADI-PEG 20 is a biologic being developed by Polaris Group to treat cancers, especially those carrying a major metabolic defect that renders such cancer cells, unlike normal cells, unable to internally synthesize arginine. Because arginine is one of the 20 amino acids that are essential for protein synthesis and survival of cells, it is believed these cancer cells become dependent upon the external supply of arginine to survive and grow. ADI-PEG 20 is designed to deplete the external supply of arginine, which causes arginine-dependent cancer cells to die while leaving the patient's normal cells unharmed.  Multiple cancers have been reported to have a high degree of arginine-dependency.

About Polaris Group

Polaris Group is a privately held biopharmaceutical company that specializes in the research and development of protein drugs to treat cancer and other debilitating diseases. The company's lead therapeutic, ADI-PEG 20, is currently being evaluated in a pivotal Phase 3 trial for hepatocellular carcinoma. Polaris Group is also investigating ADI-PEG 20 as a treatment for other cancers, such as leukemia, lymphoma, melanoma, mesothelioma, non-small cell lung carcinoma, sarcoma, breast, ovarian, and pancreatic cancer. In addition to the ADI-PEG 20 program, Polaris Group is researching and developing other biotherapeutic agents and is advancing a small molecule drug program that utilizes a rational structure-based approach to design novel compounds that inhibit the biological function of cancer-related protein targets.

For additional information please visit www.polarispharma.com

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SOURCE Polaris Group