ACHN 2017 Annual Report

Achillion Pharmaceuticals, Inc. Notes to Financial Statements—(Continued) (in thousands, except per share amounts) The following table summarizes the contractual maturities of the Company’s investments: December 31, 2017 December 31, 2016 Mature in less than one year . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $256,578 $286,558 Mature in one to five years . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30,511 27,657 Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $287,089 $314,215 7. Prepaid Expenses and Other Current Assets A summary of prepaid expenses and other current assets is as follows: As of December 31, 2017 2016 Prepaid research and development costs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $1,599 $1,228 Tax credit receivable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275 410 Software and maintenance agreements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 465 416 Interest receivable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,260 1,010 Other prepaid expenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205 396 Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $3,804 $3,460 8. Fixed Assets, net A summary of property and equipment is as follows: As of December 31, 2017 2016 Laboratory equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $ 4,277 $ 4,252 Office equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,885 1,729 Leasehold improvements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4,706 4,598 Construction in process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 33 10,876 10,612 Less—accumulated depreciation and amortization . . . . . . . . . . . . . . . . . . . . . . . (8,060) (7,133) Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $ 2,816 $ 3,479 Depreciation expense was $1,126, $955 and $693 for the years ended December 31, 2017, 2016 and 2015, respectively. F-19