Grant Revenues	3 Months Ended
Mar. 31, 2018
Grant Revenues [Abstract]
Grant Revenues	5. Grant Revenues In June 2015, the Company entered into a Cancer Research Grant Contract (“Grant Contract”) with CPRIT, under which CPRIT awarded a grant not to exceed $19.8 million for use in developing cancer treatments by exploiting the metabolism of cancer cells. The Grant Contract covers a four-year period from June 1, 2014 through May 31, 2018. Upon commercialization of the product, the terms of the Grant Contract require the Company to pay tiered royalties in the low to mid-single digit percentages. Such royalties reduce to less than one percent after a mid-single-digit multiple of the grant funds have been paid to CPRIT as royalties. The Company recognized grant revenue of $1.5 million and $1.0 million in the three months ended March 31, 2018 and 2017, respectively, for qualified expenditures under the grant. As of March 31, 2018 and December 31, 2017, the Company had outstanding grant receivables of $3.4 million and $3.1 million, respectively, for the grant expenditures that were paid but had not been reimbursed and deferred revenue of $0 and $20,000, respectively, for proceeds received but for which the costs had not been incurred or the conditions of the award had not been met.

5. Grant Revenues

In June 2015, the Company entered into a Cancer Research Grant Contract (“Grant Contract”) with CPRIT, under which CPRIT awarded a grant not to exceed $19.8 million for use in developing cancer treatments by exploiting the metabolism of cancer cells. The Grant Contract covers a four-year period from June 1, 2014 through May 31, 2018.

Upon commercialization of the product, the terms of the Grant Contract require the Company to pay tiered royalties in the low to mid-single digit percentages. Such royalties reduce to less than one percent after a mid-single-digit multiple of the grant funds have been paid to CPRIT as royalties.

The Company recognized grant revenue of $1.5 million and $1.0 million in the three months ended March 31, 2018 and 2017, respectively, for qualified expenditures under the grant. As of March 31, 2018 and December 31, 2017, the Company had outstanding grant receivables of $3.4 million and $3.1 million, respectively, for the grant expenditures that were paid but had not been reimbursed and deferred revenue of $0 and $20,000, respectively, for proceeds received but for which the costs had not been incurred or the conditions of the award had not been met.