Topline Safety and Clinical Activity Phase 1 Data Expected in 4Q 2018

AUSTIN, TX, USA I April 02, 2018 I Aeglea BioTherapeutics, Inc. (NASDAQ:AGLE), a clinical-stage biotechnology company that designs and develops innovative human enzyme therapeutics for patients with rare genetic diseases and cancer, today announced treatment of the first patients with pegzilarginase in two small cell lung cancer (SCLC) trials, the single-agent Phase 1 cohort expansion and the Phase 1/2 combination trial with KEYTRUDA®, an anti-PD-1 therapy marketed by Merck (known as MSD outside the United States and Canada). Aeglea expects to report topline safety and clinical activity data from both trials in the fourth quarter of 2018.

The SCLC cohort expansion is one of three arms in a Phase 1 trial exploring pegzilarginase monotherapy in arginine dependent cancers. The combination therapy is part of the Company’s clinical collaboration to evaluate the use of pegzilarginase with KEYTRUDA, for the treatment of patients with SCLC. The multicenter Phase 1/2 study will evaluate overall response rate in patients with extensive disease SCLC who have relapsed or progressed after receiving platinum-based chemotherapy.

“Given Aeglea’s encouraging preclinical data in small cell lung cancer, we believe there is a strong rationale for arginine depletion in this cancer indication,” said Anthony Quinn, M.B Ch.B, Ph.D., interim chief executive officer of Aeglea. “We are excited to be studying arginine depletion with pegzilarginase in both a monotherapy and combination setting, as the data from both trials will provide a broad understanding of the impact of arginine depletion in small cell lung cancer.”

“Treating the initial patients with small cell lung cancer in both of these clinical trials is an important milestone for Aeglea as we develop innovative approaches for the management of arginine dependent cancers,” said James Wooldridge, M.D., chief medical officer of Aeglea. “Small cell lung cancer is a challenging disease, and since the five-year survival rate is only about 6%, there is significant unmet need. Our intent is to confirm the safety profile and the Phase 2 dose as we look for signals of meaningful clinical activity.”

In addition to the two clinical trials in cancer, the Company is conducting an open-label Phase 1/2 trial and a long-term extension trial in patients with Arginase 1 Deficiency, a rare genetic disease.

About Pegzilarginase (AEB1102) in Cancer
Pegzilarginase is an enhanced human arginase that enzymatically degrades the amino acid arginine. In some cancers, tumor cells stop producing specific amino acids and must acquire them from the blood, making the tumor cells susceptible to starvation through depletion of those amino acids. Aeglea is developing pegzilarginase to exploit vulnerabilities in some cancers that lead to an increased dependency on extracellular arginine. Pegzilarginase targets these arginine dependent cancers by depleting blood arginine levels to below the normal range. Preclinical data demonstrated that the resulting arginine starvation inhibits proliferation, induces cell death, increases turnover of cell components and promotes anti-tumor immune responses. The Company’s Phase 1 data in advanced solid tumors demonstrated that pegzilarginase was well tolerated at doses that produced marked and sustained reductions in blood arginine levels below the normal range.

About Aeglea BioTherapeutics
Aeglea is a clinical-stage biotechnology company that designs and develops innovative human enzyme therapeutics for patients with rare genetic diseases and cancer. The Company is developing pegzilarginase, its lead investigational therapy, for the treatment of Arginase 1 Deficiency, as monotherapy in arginine-dependent cancers and in combination with an immune checkpoint inhibitor for small cell lung cancer. In addition, Aeglea has an active research pipeline of other human enzyme-based approaches in both therapeutic areas. For more information, please visit http://aegleabio.com.

SOURCE: Aeglea BioTherapeutics