Australia Research and Development Tax Incentive	9 Months Ended
Sep. 30, 2019
Research And Development [Abstract]
Australia Research and Development Tax Incentive	9. Australia Research and Development Tax Incentive The Company’s wholly owned subsidiary, Zafgen Australia Pty Limited, which conducts core research and development activities on behalf of the Company, is eligible to receive a 43.5% refundable tax incentive for qualified research and development activities through December 31, 2018 and 41% beginning January 1, 2019. For the three months ended September 30, 2019 and 2018, less than $0.1 million and $0.3 million, respectively, were recorded as a reduction to research and development expenses in the condensed consolidated statements of operations. For the nine months ended September 30, 2019 and 2018, $0.2 million and $1.3 million, respectively, were recorded as a reduction to research and development expenses in the condensed consolidated statements of operations. These amounts represented 41% and 43.5%, respectively, of the Company’s qualified research and development spending in Australia. The refund is denominated in Australian dollars and, therefore, the related receivable is re-measured into U.S. dollars as of each reporting date. For the three months ended September 30, 2019 and 2018, the Company recorded in its condensed consolidated statements of operations unrealized foreign currency exchange losses of less than $0.1 million related to this tax incentive receivable. For the nine months ended September 30, 2019 and 2018, the Company recorded in its condensed consolidated statements of operations unrealized foreign currency exchange losses of less than $0.1 million and $0.1 million, respectively, related to this tax incentive receivable. As of September 30, 2019 and December 31, 2018, the Company’s tax incentive receivable from the Australian government was $0.2 million and $1.5 million, respectively.

Australia Research and Development Tax Incentive

9 Months Ended

Sep. 30, 2019

Australia Research and Development Tax Incentive

9. Australia Research and Development Tax Incentive

The Company’s wholly owned subsidiary, Zafgen Australia Pty Limited, which conducts core research and development activities on behalf of the Company, is eligible to receive a 43.5% refundable tax incentive for qualified research and development activities through December 31, 2018 and 41% beginning January 1, 2019. For the three months ended September 30, 2019 and 2018, less than $0.1 million and $0.3 million, respectively, were recorded as a reduction to research and development expenses in the condensed consolidated statements of operations. For the nine months ended September 30, 2019 and 2018, $0.2 million and $1.3 million, respectively, were recorded as a reduction to research and development expenses in the condensed consolidated statements of operations. These amounts represented 41% and 43.5%, respectively, of the Company’s qualified research and development spending in Australia. The refund is denominated in Australian dollars and, therefore, the related receivable is re-measured into U.S. dollars as of each reporting date. For the three months ended September 30, 2019 and 2018, the Company recorded in its condensed consolidated statements of operations unrealized foreign currency exchange losses of less than $0.1 million related to this tax incentive receivable. For the nine months ended September 30, 2019 and 2018, the Company recorded in its condensed consolidated statements of operations unrealized foreign currency exchange losses of less than $0.1 million and $0.1 million, respectively, related to this tax incentive receivable. As of September 30, 2019 and December 31, 2018, the Company’s tax incentive receivable from the Australian government was $0.2 million and $1.5 million, respectively.