ADI‑PEG 20 plus FOLFOX Shows Robust Anti-tumor Activity in Advanced Hepatocellular Carcinoma

SAN DIEGO, January 19, 2017 – Polaris Group announced today results from an ongoing phase 1b study conducted at Memorial Sloan Kettering Cancer Center that tests combining ADI‑PEG 20 with folinic acid (leucovorin), fluorouracil and oxaliplatin (FOLFOX) in patients with advanced hepatocellular carcinoma (HCC) and other gastrointestinal malignancies. The results will be presented at the 2017 Gastrointestinal Cancers Symposium in San Francisco.

Thirteen HCC patients, all with Child-Pugh A and progressed on sorafenib, were enrolled in the single-arm, open label study to assess the safety and preliminary activity of ADI+FOLFOX. The treatment was well tolerated, with no dose-limiting toxicities observed. The treatment brought rapid and sustained serum arginine depletion. Three HCC patients (23%) had a partial response, and 6 patients (46%) had stable disease for a disease control rate of 69%.

“We are excited to see that ADI+FOLFOX demonstrated encouraging anti-tumor activity in the 2nd-line or later setting for advanced HCC patients,” said John Bomalaski, M.D., Executive Vice President, Medical Affairs at Polaris Pharmaceuticals, Inc. “We are planning for further clinical investigations in order to bring a safe and effective treatment to these patients.”

About ADI‑PEG 20

ADI‑PEG 20 is a biologic being developed by Polaris Group to treat cancers carrying a major metabolic defect that renders them unable to internally synthesize arginine. Because arginine is essential for protein synthesis and survival of cells, 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, causing 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 and can potentially be treated with ADI‑PEG 20.

About Polaris Group

Polaris Group specializes in the research and development of protein drugs to treat cancer and other debilitating diseases. In addition to the ADI‑PEG 20 program, Polaris Group is developing other biotherapeutic agents including 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.