Aeglea BioTherapeutics Holdings LLC is developing enzymes to starve tumors that depend on outside sources of specific amino acids. Aeglea's engineered human enzymes may offer lower immunogenicity and greater activity than natural versions further along in development.

Since the 1990s, clinicians have used asparaginase enzymes to treat acute lymphoblastic leukemia (ALL). For reasons not yet understood, ALL cells tend to lose their ability to make asparagine.