Research and License Agreements	6 Months Ended
Jun. 30, 2016
Licensing Agreements [Abstract]
Research and License Agreements	10. Research and License Agreements University Research Agreement In December 2013, the Company entered into a research agreement with the University of Texas at Austin (the “University”). Under the terms of this research agreement, the Company engaged the University to perform certain nonclinical research activities related to the systemic depletion of amino acids for cancer therapy and rare disease therapy. Under the research agreement, the Company was required to pay the University an annual amount not to exceed $386,000 during the one year term of the agreement from the effective date. The term and maximum expenditure limitation were subsequently extended and increased through four subsequent amendments through August 31, 2016 for a combined $1.0 million under the agreement, including an amendment in January 2016 increasing the maximum expenditure limitation by $82,000 for equipment purchased by the University on behalf of the Company. The Company made no payments to the University under the research agreement in the three months ended June 30, 2016 and 2015 and made payments of $457,000 and $188,000 in the six months ended June 30, 2016 and 2015, respectively. License Agreements In December 2013, the Company entered into two license agreements with the University. Under the terms of each license agreement, the University granted the Company an exclusive worldwide license to develop, manufacture, and commercialize therapeutics related to the University’s engineered cysteine/cystine degrading enzymes and engineered methionine degrading enzymes for use in the treatment of human diseases. Under each license agreement, the Company paid the University an up-front fee of $10,000 in 2013 and will pay annual license fees increasing from $5,000 in 2016 to $25,000 in 2018 and thereafter. The Company may be required to make future payments of up to $6.4 million contingent upon attainment of various development and regulatory approval milestones for the licensed product in any country. The milestone payments are payable in various amounts upon the start of different phases of clinical trials, application for, and receipt of regulatory approval, with $5.0 million payable upon the receipt of regulatory approval and a $500,000 payment payable on final regulatory approval of a second indication. Additionally, upon commercial sales of the product, the Company will be required to pay to the University a single-digit royalty on net sales of the licensed products in any country or region, if such product sales are ever achieved.

10. Research and License Agreements

University Research Agreement

In December 2013, the Company entered into a research agreement with the University of Texas at Austin (the “University”). Under the terms of this research agreement, the Company engaged the University to perform certain nonclinical research activities related to the systemic depletion of amino acids for cancer therapy and rare disease therapy.

Under the research agreement, the Company was required to pay the University an annual amount not to exceed $386,000 during the one year term of the agreement from the effective date. The term and maximum expenditure limitation were subsequently extended and increased through four subsequent amendments through August 31, 2016 for a combined $1.0 million under the agreement, including an amendment in January 2016 increasing the maximum expenditure limitation by $82,000 for equipment purchased by the University on behalf of the Company. The Company made no payments to the University under the research agreement in the three months ended June 30, 2016 and 2015 and made payments of $457,000 and $188,000 in the six months ended June 30, 2016 and 2015, respectively.

License Agreements

In December 2013, the Company entered into two license agreements with the University. Under the terms of each license agreement, the University granted the Company an exclusive worldwide license to develop, manufacture, and commercialize therapeutics related to the University’s engineered cysteine/cystine degrading enzymes and engineered methionine degrading enzymes for use in the treatment of human diseases.

Under each license agreement, the Company paid the University an up-front fee of $10,000 in 2013 and will pay annual license fees increasing from $5,000 in 2016 to $25,000 in 2018 and thereafter. The Company may be required to make future payments of up to $6.4 million contingent upon attainment of various development and regulatory approval milestones for the licensed product in any country. The milestone payments are payable in various amounts upon the start of different phases of clinical trials, application for, and receipt of regulatory approval, with $5.0 million payable upon the receipt of regulatory approval and a $500,000 payment payable on final regulatory approval of a second indication. Additionally, upon commercial sales of the product, the Company will be required to pay to the University a single-digit royalty on net sales of the licensed products in any country or region, if such product sales are ever achieved.