Funding Arrangements	12 Months Ended
Dec. 31, 2019
Funding Arrangements
Funding Arrangements	8. Funding Arrangements CARB-X In March 2017 and October 2017, the Company entered into funding arrangements with the Trustees of Boston University to utilize funds from the U.S. government through the Combating Antibiotic Resistant Bacteria Biopharmaceutical Accelerator, or CARB‑X, program, in support of our ETX0282 and NBP programs. In September 2019 the funding arrangements were amended to increase the amount of specified research and development expenditures of the Company that could be covered from $16.4 million to $16.8 million from April 2017 through September 2021. The Company recognized grant income in connection with the CARB-X agreements of $2.3 million and $4.8 million for the years ended December 31, 2019 and 2018, respectively. The Company received $2.6 million and $3.8 million of payments under the grants during the years ended December 31, 2019 and 2018, respectively. The Company recorded a receivable to reflect unreimbursed, eligible costs incurred under the CARB-X agreements in the amount of $1.2 million and $1.5 million as of December 31, 2019 and December 31, 2018, respectively. USAMRAA In December 2016, the Company entered into a funding arrangement with the U.S. Army Medical Research Acquisition Activity, or the USAMRAA grant, that covers up to $1.1 million of specified research expenditures of the Company incurred from December 2016 through June 2019, or the performance period. The Company has until September 2022 to obtain the reimbursements from USAMRAA for the specified research expenditures incurred and paid by the Company during the performance period. The Company recognized grant income of $37,000 and $0.5 million for the years ended December 31, 2019 and 2018, respectively. The Company received $0.2 million and $0.9 million of payments under the grant for the years ended December 31, 2019 and 2018, respectively. The Company recorded a receivable to reflect unreimbursed, eligible costs incurred under the grant in the amount of $0.2 million as of December 31, 2018. The Company received the final reimbursement payment under this grant in May 2019, therefore no receivable for unreimbursed costs was recorded as of December 31, 2019.

8. Funding Arrangements

CARB-X

In March 2017 and October 2017, the Company entered into funding arrangements with the Trustees of Boston University to utilize funds from the U.S. government through the Combating Antibiotic Resistant Bacteria Biopharmaceutical Accelerator, or CARB‑X, program, in support of our ETX0282 and NBP programs. In September 2019 the funding arrangements were amended to increase the amount of specified research and development expenditures of the Company that could be covered from $16.4 million to $16.8 million from April 2017 through September 2021.

The Company recognized grant income in connection with the CARB-X agreements of $2.3 million and $4.8 million for the years ended December 31, 2019 and 2018, respectively. The Company received $2.6 million and $3.8 million of payments under the grants during the years ended December 31, 2019 and 2018, respectively. The Company recorded a receivable to reflect unreimbursed, eligible costs incurred under the CARB-X agreements in the amount of $1.2 million and $1.5 million as of December 31, 2019 and December 31, 2018, respectively.

USAMRAA

In December 2016, the Company entered into a funding arrangement with the U.S. Army Medical Research Acquisition Activity, or the USAMRAA grant, that covers up to $1.1 million of specified research expenditures of the Company incurred from December 2016 through June 2019, or the performance period. The Company has until September 2022 to obtain the reimbursements from USAMRAA for the specified research expenditures incurred and paid by the Company during the performance period.

The Company recognized grant income of $37,000 and $0.5 million for the years ended December 31, 2019 and 2018, respectively. The Company received $0.2 million and $0.9 million of payments under the grant for the years ended December 31, 2019 and 2018, respectively. The Company recorded a receivable to reflect unreimbursed, eligible costs incurred under the grant in the amount of $0.2 million as of December 31, 2018. The Company received the final reimbursement payment under this grant in May 2019, therefore no receivable for unreimbursed costs was recorded as of December 31, 2019.