Licensing Agreements	12 Months Ended
Dec. 31, 2015
Licensing Agreements [Abstract]
Licensing Agreements	10. Licensing Agreements Symbioscience License Agreement In December 2014, the Company entered into an exclusive license agreement with Mars, Inc., by and through its Mars Symbioscience division, or Symbioscience, under which the Company has been granted the exclusive, worldwide license rights to develop and commercialize Symbioscience’s portfolio of arginase inhibitors for use in human healthcare (Symbioscience License Agreement). Under the terms of the Symbioscience License Agreement, the Company paid Symbioscience an upfront license fee of $0.3 million, which was recorded as research and development expense in 2014. For the years ended December 31, 2015 and 2014, the Company recognized expense related to its licensing arrangement with Symbioscience of $0.2 million and $0.3 million, respectively, which was recorded in research and development expense in the statement of operations. The Company may make future payments of up to $24.2 million contingent upon attainment of various development and regulatory milestones and $95.0 million contingent upon attainment of various sales milestones. Additionally, the Company will pay royalties on sales of the licensed product, if such product sales are ever achieved. If the Company develops additional licensed products, after achieving regulatory approval of the first licensed product, the Company would owe additional regulatory milestone payments and additional royalty payments based on sales of such additional licensed products. TransTech License Agreement In March 2015, the Company entered into a License and Research agreement with High Point Pharmaceuticals, LLC and TransTech Pharma LLC, or collectively TransTech, under which the Company obtained an exclusive, worldwide license to develop and commercialize TransTech’s hexokinase II inhibitors (TransTech License Agreement). Under the terms of the TransTech License Agreement, the Company paid TransTech an initial license fee of $0.6 million, which was recorded in research and development expense in 2015. For the year ended December 31, 2015, the Company recognized expense related to its licensing arrangement with TransTech of $0.6 million in research and development expense in the statement of operations. The Company may pay potential development and regulatory milestone payments totaling up to $30.5 million for the first licensed product. TransTech is eligible for an additional $77.0 million in potential sales-based milestones, as well as royalty payments, at mid-single digit royalty rates, based on tiered sales of the first commercialized licensed product. If the Company develops additional licensed products, after achieving regulatory approval of the first licensed product, the Company would owe additional regulatory milestone payments and additional royalty payments based on sales of such additional licensed products. The Company will be responsible for the worldwide development and commercialization of the licensed products, at its cost.

10. Licensing Agreements

Symbioscience License Agreement

In December 2014, the Company entered into an exclusive license agreement with Mars, Inc., by and through its Mars Symbioscience division, or Symbioscience, under which the Company has been granted the exclusive, worldwide license rights to develop and commercialize Symbioscience’s portfolio of arginase inhibitors for use in human healthcare (Symbioscience License Agreement). Under the terms of the Symbioscience License Agreement, the Company paid Symbioscience an upfront license fee of $0.3 million, which was recorded as research and development expense in 2014. For the years ended December 31, 2015 and 2014, the Company recognized expense related to its licensing arrangement with Symbioscience of $0.2 million and $0.3 million, respectively, which was recorded in research and development expense in the statement of operations.

The Company may make future payments of up to $24.2 million contingent upon attainment of various development and regulatory milestones and $95.0 million contingent upon attainment of various sales milestones. Additionally, the Company will pay royalties on sales of the licensed product, if such product sales are ever achieved. If the Company develops additional licensed products, after achieving regulatory approval of the first licensed product, the Company would owe additional regulatory milestone payments and additional royalty payments based on sales of such additional licensed products.

TransTech License Agreement

In March 2015, the Company entered into a License and Research agreement with High Point Pharmaceuticals, LLC and TransTech Pharma LLC, or collectively TransTech, under which the Company obtained an exclusive, worldwide license to develop and commercialize TransTech’s hexokinase II inhibitors (TransTech License Agreement). Under the terms of the TransTech License Agreement, the Company paid TransTech an initial license fee of $0.6 million, which was recorded in research and development expense in 2015. For the year ended December 31, 2015, the Company recognized expense related to its licensing arrangement with TransTech of $0.6 million in research and development expense in the statement of operations.

The Company may pay potential development and regulatory milestone payments totaling up to $30.5 million for the first licensed product. TransTech is eligible for an additional $77.0 million in potential sales-based milestones, as well as royalty payments, at mid-single digit royalty rates, based on tiered sales of the first commercialized licensed product. If the Company develops additional licensed products, after achieving regulatory approval of the first licensed product, the Company would owe additional regulatory milestone payments and additional royalty payments based on sales of such additional licensed products. The Company will be responsible for the worldwide development and commercialization of the licensed products, at its cost.