96 Comparison of the Years Ended December 31, 2017 and 2016 The following table summarizes our results of operations for the periods indicated: Year Ended December 31, Change 2017 2016 Dollar Percent (in thousands) Operating expenses: Research and development......................................................... $ 22,022 $ 14,053 $ 7,969 57% General and administrative......................................................... 3,499 3,098 401 13% Loss from operations.................................................................. (25,521) (17,151) (8,370) 49% Interest expense (includes $914 attributable to related parties for the year ended December 31, 2017) ...................... (1,185) (6) (1,179) * Other income (expense), net (includes $1,008 attributable to related parties for the year ended December 31, 2017 ) ..... (1,230) 25 (1,255) * Net loss....................................................................................... $ (27,936) $ (17,132) $ (10,804) 63% * Percentage is not meaningful Research and Development Expenses Research and development expenses increased $8.0 million, or 57%, from the year ended December 31, 2016 to the year ended December 31, 2017. The following table summarizes our research and development expenses: Year Ended December 31, 2017 2016 Change (in thousands) ABC Platform external expenses (1) .......................................................... $ 931 $ 7,582 $ (6,651) KSI-301 program external expenses (2)..................................................... 14,021 — 14,021 Payroll and personnel expenses (3) ............................................................ 3,288 3,375 (87) Other research and development expenses (4) ........................................... 3,782 3,096 686 Total research and development expenses........................................... $ 22,022 $ 14,053 $ 7,969 (1) ABC Platform external expenses primarily relates to manufacturing of biopolymer intermediate drug substance which can be used with multiple product candidates. These expenses are primarily for services provided by CMOs and CROs. (2) KSI-301 program external expenses relates to development of KSI-301, including manufacturing costs. These expenses are primarily for services provided by CMOs and CROs. (3) Payroll and personnel expenses includes salaries, benefits and stock-based compensation for our personnel involved in research and development activities. These expenses are separately classified and not allocated to specific programs because these expenses relate to multiple programs. (4) Other research and development expenses includes direct costs related to research and development activities other than those listed above. ABC Platform external expenses decreased $6.7 million during the year ended December 31, 2017 as compared to 2016. The decrease was primarily attributable to the increased focus on the development of KSI-301 in fiscal 2017. KSI-301 program external expenses were $14.0 million for the year ended December 31, 2017. Payroll and personnel expenses did not significantly change during the year ended December 31, 2017 as compared to 2016. Other research and development expenses increased $0.7 million during the year ended December 31, 2017 as compared to 2016. The increase is attributable to the increase of $0.7 million in CMO and external contractor expenses, increase of $0.5 million in overhead and depreciation expenses, which was offset by a decrease in lab expenses of $0.5 million.