99 Summary Statement of Cash Flows The following table sets forth the primary sources and uses of cash and cash equivalents for each of the periods presented below: Year Ended December 31, 2018 2017 2016 (in thousands) Net cash (used in) provided by: Operating activities........................................................................................ $ (29,031) $ (17,655) $ (16,047) Investing activities......................................................................................... $ (581) $ (209) $ (771) Financing activities........................................................................................ $ 116,471 $ 9,637 $ (120) Net increase (decrease) in cash, cash equivalents and restricted cash .......... $ 86,859 $ (8,227) $ (16,938) Cash Flows from Operating Activities Net cash used in operating activities was $29.0 million for year ended December 31, 2018. Cash used in operating activities was primarily due to the use of funds in our operations to continue to develop KSI-301 and in connection with our IPO, resulting in a net loss of $41.4 million, adjusted by non-cash charges of $18.8 million offset by a change in operating assets and liabilities of $6.4 million. The non-cash charges consisted of $5.5 million in loss on extinguishment of debt, $2.7 million in loss due to change in fair value of redeemable convertible preferred stock warrant liability, $2.0 million in loss due to change in fair value of derivative instrument related to the convertible notes issued in February 2018, $5.5 million in non- cash interest expense and amortization of debt discount and issuance costs, $0.5 million of depreciation expense, and $2.6 million of stock-based compensation. The change in net operating assets and liabilities was primarily due to a decrease in accrued liabilities of $2.1 million mainly related to a decrease in accrued research and development expenses offset by an increase in accrued compensation expenses, a decrease in accounts payable of $2.3 million due to the timing of vendor payments and an increase in prepaid and other assets of $2.0 million mainly due to an increase in advance payments. Net cash used in operating activities was $17.7 million for the year ended December 31, 2017. Cash used in operating activities was primarily due to the use of funds in our operations to develop KSI-301, resulting in a net loss of $27.9 million, adjusted by non-cash charges of $3.2 million offset by a change in operating assets and liabilities of $7.0 million. The non- cash charges primarily consisted of $1.3 million in expense due to change in fair value of redeemable convertible preferred stock warrant liability, $1.2 million in non-cash interest expense and amortization of debt discount and issuance costs, $0.5 million of depreciation and amortization, and $0.3 million of stock-based compensation. The change in net operating assets and liabilities was primarily due to an increase in accrued liabilities of $4.3 million mainly related to an increase in accrued research and development and accrued compensation expenses, an increase in accounts payable of $2.2 million due to the timing of vendor payments and a decrease in prepaid and other assets of $0.4 million mainly due to amortization of prepaid expenses. Net cash used in operating activities was $16.0 million for the year ended December 31, 2016. Cash used in operating activities was due to the use of funds in our operations to develop our ABC Platform, resulting in a net loss of $17.1 million, offset by non-cash charges of $0.3 million of depreciation expense and $0.3 million of stock-based compensation expense, a decrease in prepaid expense and other current assets of $0.3 million, and an increase in accrued liabilities and other current assets of $0.2 million. Cash Flows from Investing Activities Net cash used in investing activities was $0.6 million for the year ended December 31, 2018 and primarily related to the purchase of property and equipment including advance deposits. Net cash used in investing activities was $0.2 million for the year ended December 31, 2017 and primarily related to purchase of property and equipment. Net cash used in investing activities was $0.8 million for the year ended December 31, 2016, which was related to $0.8 million used in the purchase of property and equipment.