Polaris Group Announces Treatment of First Patient in Phase 1 Study of ADI‑PEG 20 Plus Pembrolizumab in Advanced Solid Tumors

SAN DIEGO, July 14, 2017 – Polaris Group announced today that the first patient has been dosed in its phase 1 trial of ADI‑PEG 20 in combination with pembrolizumab for the treatment of advanced solid tumors. In addition to a global phase 2/3 trial in malignant plural mesothelioma featuring ADI‑PEG 20 in combination with pemetrexed and cisplatin (PemCis), Polaris Group is currently conducting multiple phase 1 clinical trials, including ADI‑PEG 20 in combination with PemCis in non-small cell lung carcinoma, glioblastoma, and uveal melanoma, in combination with low-dose cytarabine in older patients with acute myeloid leukemia and in combination with FOLFOX in hepatocellular carcinoma, gastric cancer, and colorectal cancer.

“In addition to its enzymatic activity to breakdown arginine, ADI‑PEG 20 has also shown immune regulating activities in pre-clinical studies. We hope the combination will further enhance pembrolizumab’s efficacy while conferring additional anti-tumor activity from ADI‑PEG 20”, said John Bomalaski, M.D., Executive Vice President, Medical Affairs at Polaris Pharmaceuticals, Inc.

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.