AUSTIN, Texas, Nov. 21, 2016 (GLOBE NEWSWIRE) -- Aeglea BioTherapeutics, Inc. (NASDAQ:AGLE), a biotechnology company committed to developing enzyme-based therapeutics in the field of amino acid metabolism to treat genetic rare diseases and cancer, today announced results of preclinical studies demonstrating that its product candidate AEB3103 suppressed the growth of tumors in models of prostate and breast cancer and extended survival in a model of chronic lymphocytic leukemia (CLL). The article entitled "Systemic depletion of serum L-Cyst(e)ine with an engineered human enzyme induces production of reactive oxygen species and suppresses tumor growth in mice" was published online today in Nature Medicine. In these preclinical models, AEB3103 deprived tumors of a key ingredient for cysteine-dependent anti-oxidant pathways, such as in the production of glutathione, which are involved in protecting tumors from oxidative stress due to reactive oxygen species (ROS). AEB3103 systemically degraded serum L-cysteine and its oxidized form L-cystine resulting in increased oxidative stress and cancer cell death. "These preclinical results suggest that the use of AEB3103 to deplete the amino acid L-cysteine has the potential to be a well-tolerated approach for treating tumors with high levels of ROS. The idea of targeting cancer with an enzyme that degrades L-cysteine was first proposed in 1961. Since then, the evidence that this is an important and unexploited vulnerability of cancer has been widely described but not effectively applied for therapeutic benefit," said David G. Lowe, Ph.D., president and chief executive officer of Aeglea. "Our results with AEB3103 also provide support for our broader cancer strategy of using well established amino acid biology to target tumor metabolism." "Preclinical findings showed that AEB3103 had a potent anti-tumor effect in multiple solid tumor models, including prostate and breast cancer, and was well tolerated for more than five months. This suggests AEB3103 could be a safe and effective alternative to experimental drugs targeting oxidative stress that are currently under clinical evaluation," said study co-author George Georgiou, Ph.D., co-founder of Aeglea and Laura Jennings Turner Chair in Engineering at the University of Texas at Austin. "As many other chemotherapeutic agents are also known to oxidatively stress cancer cells, we are looking forward to exploring AEB3103 in combination with ROS-inducing drugs as a potential cancer treatment."