in addition , in connection with the maruishi agreement , maruishi purchased 842,105 shares of our common stock for an aggregate purchase price of $ 8.0 million . in april 2012 , we entered into a license agreement , or the ckdp agreement with chong kun dang pharmaceutical corporation , or ckdp , in south korea , under which we granted ckdp an exclusive license to develop , manufacture and commercialize drug products containing cr845/difelikefalin in south korea . we and ckdp are each required to use commercially reasonable efforts , at our respective expense , to develop , obtain regulatory approval for and commercialize cr845/difelikefalin in the united states and south korea , respectively . under the terms of the ckdp agreement , we received a non-refundable and non-creditable upfront license fee of $ 0.6 million and are eligible to receive up to an aggregate of $ 2.3 million in clinical development milestones and $ 1.5 million in regulatory milestones . in addition , ckdp purchased , 69,444 shares of our common stock in consideration for $ 0.4 million . during the year ended december 31 , 2012 , we received $ 0.6 million , net of foreign taxes , from ckdp upon the completion of a phase 2 trial of cr845/difelikefalin in pain in the united states and a phase 1a trial of oral cr845/difelikefalin for uremic pruritus in the united states . during the year ended december 31 , 2015 , we met the milestone criteria , as set forth in the ckdp agreement , for completion of a phase 1b trial of oral cr845/difelikefalin for uremic pruritus in the united states and for completion of a phase 2 trial of cr845/difelikefalin in uremic pruritus patients in the united states for which we received milestone payments totaling $ 0.6 million ( net of south korean withholding tax ) from ckdp . we are also eligible to receive tiered royalties with percentages ranging from the high single digits to the high teens , based on net sales of products containing cr845/difelikefalin in south korea , if any , and share in any sub-license fees . components of operating results revenue to date , we have not generated any revenue from product sales and do not expect to generate any revenue from the sale of products in the foreseeable future . substantially all of our revenue recognized to date has consisted of upfront payments under license agreements with vfmcrp , maruishi and ckdp , and milestone and sub-license payments under license agreements with ckdp and maruishi for cr845/difelikefalin , some or all of which was deferred upon receipt , as well as license agreements for cr665 , our first-generation drug program for which development efforts have ceased and clinical compound sales from certain license agreements . to date , we have earned a total of $ 5.2 million in clinical development or regulatory milestone payments , sub-license fees under our maruishi and ckdp collaborations , net of contractual foreign currency adjustments and south korean withholding taxes , and clinical compound sales from certain license agreements . we have not yet received any milestone payments under the vfmcrp agreement or royalties under any of our collaborations . 79 research and development ( r & d ) our r & d expenses relate primarily to the development of cr845/difelikefalin . r & d expenses consist of expenses incurred in performing r & d activities , including compensation and benefits for full-time r & d employees , clinical trial and related clinical manufacturing expenses , third-party formulation expenses , fees paid to contract research organizations , or cros , and other consultants , stock-based compensation for r & d employees and consultants and other outside expenses . our r & d expenses also included expenses related to preclinical activities for our earlier stage programs in prior periods and may include such expenses in the future . r & d costs are expensed as incurred . non-refundable advance payments for goods or services to be received in the future for use in r & d activities are deferred and capitalized . the capitalized amounts are expensed as the related goods are delivered or the services are performed . most of our r & d costs have been external costs , which we track on a program-by program basis . our internal r & d costs are primarily compensation expenses for our full-time r & d employees . we do not track internal r & d costs on a program-by-program basis . r & d activities are central to our business model . product candidates in later stages of clinical development generally have higher development costs than those in earlier stages of clinical development , primarily due to the increased size and duration of later-stage clinical trials . based on our current development plans , we presently expect that our r & d expenses for 2019 will increase over those for 2018. however , it is difficult to determine with certainty the duration and completion costs of our current or future nonclinical programs and clinical trials of our product candidates , or if , when or to what extent we will generate revenues from the commercialization and sale of any of our product candidates that obtain regulatory approval . we may never succeed in achieving regulatory approval for any of our product candidates . story_separator_special_tag we are also eligible to receive tiered double-digit royalty payments based on annual net sales , as defined in the vfmcrp agreement , of cr845/difelikefalin injection in the licensed territories . under the maruishi agreement , we are also potentially eligible to earn up to an aggregate of $ 6.0 million in clinical development milestones and $ 4.5 million in regulatory milestones , before any foreign exchange adjustment , as well as tiered royalties , with percentages ranging from the low double digits to the low twenties , based on net sales of products containing cr845/difelikefalin in japan , if any , and share in any sub-license fees . as of december 31 , 2018 , we have received milestone payments of $ 2.5 million before contractual foreign currency exchange adjustments . during the first quarter of 2017 , maruishi entered into a sub-license agreement with another japanese pharmaceutical company for the development and sales/marketing of cr845/difelikefalin in patients with uremic pruritus in japan , as a result of which we received a payment of $ 843 thousand . under the ckdp agreement , we are potentially eligible to earn up to an aggregate of $ 2.3 million in clinical development milestones and $ 1.5 million in regulatory milestones , before south korean withholding tax , as well as tiered royalties with percentages ranging from the high single digits to the high teens , based on net sales of products containing cr845/difelikefalin in south korea , if any , and share in any sub-license fees . as of december 31 , 2018 , we have received milestone payments of $ 1.5 million before south korean withholding tax . 85 the next potential milestone that could result in us receiving payment under the ckdp agreement will be for a clinical development milestone for the completion by us in the united states of a phase 3 trial of cr845/difelikefalin in uremic pruritus . if achieved , this milestone will result in a payment of $ 750 thousand , before south korean withholding tax , being due to us . our ability to earn these payments and their timing is dependent upon the outcome of i.v . and oral cr845/difelikefalin development activities and , potentially , commercialization . however , our receipt of any further such amounts is uncertain at this time and we may never receive any more of these amounts . funding requirements our primary uses of capital have been , and we expect will continue to be , compensation and related expenses , third-party clinical r & d services and clinical costs . in the past , we have also previously used capital for laboratory and related supplies . since inception , we have incurred significant operating and net losses . our net losses were $ 74.0 million , $ 58.1 million and $ 57.3 million for the years ended december 31 , 2018 , 2017 and 2016 , respectively . as of december 31 , 2018 , we had an accumulated deficit of $ 294.4 million . we expect to continue to incur significant expenses and operating and net losses in the near future . our net losses may fluctuate significantly from quarter to quarter and year to year , depending on the timing of our clinical trials , the receipt of additional milestone payments , if any , under our licensing and collaborations with vfmcrp , maruishi and ckdp , the receipt of payments under any future collaborations and or licensing agreements we may enter into , and our expenditures on other r & d activities . we anticipate that our expenses will increase as we : continue the development of korsuva ( cr845/difelikefalin ) injection for ckd-ap in dialysis patients ; continue the development of oral korsuva ( cr845/difelikefalin ) for ckd-ap and other diseases associated with pruritus , such as cld-ap ; explore the potential to further develop i.v . cr845/difelikefalin in the post-operative setting ; conduct r & d of any potential future product candidates ; seek regulatory approvals for i.v . cr845/difelikefalin and any product candidates that successfully complete clinical trials ; establish a sales , marketing and distribution infrastructure and scale up external manufacturing capabilities to commercialize any products for which we may obtain regulatory approval ; maintain , expand and protect our global intellectual property portfolio ; hire additional clinical , quality control and scientific personnel ; and add operational , financial and management information systems and personnel , including personnel to support our drug development and potential future commercialization efforts . the successful development of any of our product candidates is highly uncertain . as such , at this time , we can not reasonably estimate or know the nature , timing and costs of the efforts that will be necessary to complete the development of i.v . cr845/difelikefalin , oral cr845/difelikefalin or our other current and future programs . we are also unable to predict when , if ever , we will generate any further material net cash inflows from cr845/difelikefalin . this is due to the numerous risks and uncertainties associated with developing medicines , including the uncertainty of : successful enrollment in , and completion of clinical trials ; receipt of marketing approvals from applicable regulatory authorities ; 86 establishing commercial manufacturing capabilities or making arrangements with third-party manufacturers ; obtaining and maintaining patent and trade secret protection and regulatory exclusivity for our product candidates ; launching commercial sales of the products , if and when approved , whether alone or in collaboration with others ; achieving meaningful penetration in the markets which we seek to serve ; and obtaining adequate coverage or reimbursement by third parties , such as commercial payers and government healthcare programs , including medicare and medicaid . a change in the outcome of any of these variables with respect to the development of i.v . cr845/difelikefalin , oral cr845/difelikefalin or any of our future product candidates would significantly change the costs and timing

net cash used in operating activities net cash used in operating activities for the year ended december 31 , 2018 consisted primarily of a net loss of $ 74.0 million , partially offset by a $ 50.5 million cash inflow from net non-cash charges and a $ 1.2 million inflow from net changes in operating assets and liabilities . net non-cash charges primarily consisted of an increase in deferred revenue of $ 42.0 million related to the vfmcrp agreement and stock-based compensation expense of $ 10.1 million ( which includes $ 1.7 million related to the vesting of restricted stock units ) , partially offset by $ 1.8 million related to amortization/accretion of available-for-sale securities . the net change in operating assets and liabilities primarily consisted of a cash inflow of $ 5.1 million from an increase in accounts payable and accrued expenses , partially offset by cash outflows of $ 3.2 million from an increase in prepaid expense , primarily related to an increase in prepaid clinical costs , and cash outflows of $ 0.8 million related to an increase in other receivables . net cash used in operating activities for the year ended december 31 , 2017 consisted primarily of a net loss of $ 58.1 million , a $ 3.0 million outflow from net changes in operating assets and liabilities and a $ 6.3 million cash inflow from net non-cash charges . the net change in operating assets and liabilities primarily consisted of cash outflows of $ 3.0 million from a decrease in accounts payable and accrued expenses . net non-cash charges primarily consisted of stock-based compensation expense of $ 6.3 million and depreciation and amortization expense of $ 0.5 million , partially offset by accretion/amortization on available-for-sale securities of $ 0.6 million .


 Write a concise suspicious activity report of the following text delimited by triple backquotes. Return your response as a formal report which covers the key points highlighting the location,dates,entity names and account holder information in chronological order of the text.
     ```net cash used in operating activities net cash used in operating activities for the year ended december 31 , 2018 consisted primarily of a net loss of $ 74.0 million , partially offset by a $ 50.5 million cash inflow from net non-cash charges and a $ 1.2 million inflow from net changes in operating assets and liabilities . net non-cash charges primarily consisted of an increase in deferred revenue of $ 42.0 million related to the vfmcrp agreement and stock-based compensation expense of $ 10.1 million ( which includes $ 1.7 million related to the vesting of restricted stock units ) , partially offset by $ 1.8 million related to amortization/accretion of available-for-sale securities . the net change in operating assets and liabilities primarily consisted of a cash inflow of $ 5.1 million from an increase in accounts payable and accrued expenses , partially offset by cash outflows of $ 3.2 million from an increase in prepaid expense , primarily related to an increase in prepaid clinical costs , and cash outflows of $ 0.8 million related to an increase in other receivables . net cash used in operating activities for the year ended december 31 , 2017 consisted primarily of a net loss of $ 58.1 million , a $ 3.0 million outflow from net changes in operating assets and liabilities and a $ 6.3 million cash inflow from net non-cash charges . the net change in operating assets and liabilities primarily consisted of cash outflows of $ 3.0 million from a decrease in accounts payable and accrued expenses . net non-cash charges primarily consisted of stock-based compensation expense of $ 6.3 million and depreciation and amortization expense of $ 0.5 million , partially offset by accretion/amortization on available-for-sale securities of $ 0.6 million .
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 Suspicious Activity Report : in addition , in connection with the maruishi agreement , maruishi purchased 842,105 shares of our common stock for an aggregate purchase price of $ 8.0 million . in april 2012 , we entered into a license agreement , or the ckdp agreement with chong kun dang pharmaceutical corporation , or ckdp , in south korea , under which we granted ckdp an exclusive license to develop , manufacture and commercialize drug products containing cr845/difelikefalin in south korea . we and ckdp are each required to use commercially reasonable efforts , at our respective expense , to develop , obtain regulatory approval for and commercialize cr845/difelikefalin in the united states and south korea , respectively . under the terms of the ckdp agreement , we received a non-refundable and non-creditable upfront license fee of $ 0.6 million and are eligible to receive up to an aggregate of $ 2.3 million in clinical development milestones and $ 1.5 million in regulatory milestones . in addition , ckdp purchased , 69,444 shares of our common stock in consideration for $ 0.4 million . during the year ended december 31 , 2012 , we received $ 0.6 million , net of foreign taxes , from ckdp upon the completion of a phase 2 trial of cr845/difelikefalin in pain in the united states and a phase 1a trial of oral cr845/difelikefalin for uremic pruritus in the united states . during the year ended december 31 , 2015 , we met the milestone criteria , as set forth in the ckdp agreement , for completion of a phase 1b trial of oral cr845/difelikefalin for uremic pruritus in the united states and for completion of a phase 2 trial of cr845/difelikefalin in uremic pruritus patients in the united states for which we received milestone payments totaling $ 0.6 million ( net of south korean withholding tax ) from ckdp . we are also eligible to receive tiered royalties with percentages ranging from the high single digits to the high teens , based on net sales of products containing cr845/difelikefalin in south korea , if any , and share in any sub-license fees . components of operating results revenue to date , we have not generated any revenue from product sales and do not expect to generate any revenue from the sale of products in the foreseeable future . substantially all of our revenue recognized to date has consisted of upfront payments under license agreements with vfmcrp , maruishi and ckdp , and milestone and sub-license payments under license agreements with ckdp and maruishi for cr845/difelikefalin , some or all of which was deferred upon receipt , as well as license agreements for cr665 , our first-generation drug program for which development efforts have ceased and clinical compound sales from certain license agreements . to date , we have earned a total of $ 5.2 million in clinical development or regulatory milestone payments , sub-license fees under our maruishi and ckdp collaborations , net of contractual foreign currency adjustments and south korean withholding taxes , and clinical compound sales from certain license agreements . we have not yet received any milestone payments under the vfmcrp agreement or royalties under any of our collaborations . 79 research and development ( r & d ) our r & d expenses relate primarily to the development of cr845/difelikefalin . r & d expenses consist of expenses incurred in performing r & d activities , including compensation and benefits for full-time r & d employees , clinical trial and related clinical manufacturing expenses , third-party formulation expenses , fees paid to contract research organizations , or cros , and other consultants , stock-based compensation for r & d employees and consultants and other outside expenses . our r & d expenses also included expenses related to preclinical activities for our earlier stage programs in prior periods and may include such expenses in the future . r & d costs are expensed as incurred . non-refundable advance payments for goods or services to be received in the future for use in r & d activities are deferred and capitalized . the capitalized amounts are expensed as the related goods are delivered or the services are performed . most of our r & d costs have been external costs , which we track on a program-by program basis . our internal r & d costs are primarily compensation expenses for our full-time r & d employees . we do not track internal r & d costs on a program-by-program basis . r & d activities are central to our business model . product candidates in later stages of clinical development generally have higher development costs than those in earlier stages of clinical development , primarily due to the increased size and duration of later-stage clinical trials . based on our current development plans , we presently expect that our r & d expenses for 2019 will increase over those for 2018. however , it is difficult to determine with certainty the duration and completion costs of our current or future nonclinical programs and clinical trials of our product candidates , or if , when or to what extent we will generate revenues from the commercialization and sale of any of our product candidates that obtain regulatory approval . we may never succeed in achieving regulatory approval for any of our product candidates . story_separator_special_tag we are also eligible to receive tiered double-digit royalty payments based on annual net sales , as defined in the vfmcrp agreement , of cr845/difelikefalin injection in the licensed territories . under the maruishi agreement , we are also potentially eligible to earn up to an aggregate of $ 6.0 million in clinical development milestones and $ 4.5 million in regulatory milestones , before any foreign exchange adjustment , as well as tiered royalties , with percentages ranging from the low double digits to the low twenties , based on net sales of products containing cr845/difelikefalin in japan , if any , and share in any sub-license fees . as of december 31 , 2018 , we have received milestone payments of $ 2.5 million before contractual foreign currency exchange adjustments . during the first quarter of 2017 , maruishi entered into a sub-license agreement with another japanese pharmaceutical company for the development and sales/marketing of cr845/difelikefalin in patients with uremic pruritus in japan , as a result of which we received a payment of $ 843 thousand . under the ckdp agreement , we are potentially eligible to earn up to an aggregate of $ 2.3 million in clinical development milestones and $ 1.5 million in regulatory milestones , before south korean withholding tax , as well as tiered royalties with percentages ranging from the high single digits to the high teens , based on net sales of products containing cr845/difelikefalin in south korea , if any , and share in any sub-license fees . as of december 31 , 2018 , we have received milestone payments of $ 1.5 million before south korean withholding tax . 85 the next potential milestone that could result in us receiving payment under the ckdp agreement will be for a clinical development milestone for the completion by us in the united states of a phase 3 trial of cr845/difelikefalin in uremic pruritus . if achieved , this milestone will result in a payment of $ 750 thousand , before south korean withholding tax , being due to us . our ability to earn these payments and their timing is dependent upon the outcome of i.v . and oral cr845/difelikefalin development activities and , potentially , commercialization . however , our receipt of any further such amounts is uncertain at this time and we may never receive any more of these amounts . funding requirements our primary uses of capital have been , and we expect will continue to be , compensation and related expenses , third-party clinical r & d services and clinical costs . in the past , we have also previously used capital for laboratory and related supplies . since inception , we have incurred significant operating and net losses . our net losses were $ 74.0 million , $ 58.1 million and $ 57.3 million for the years ended december 31 , 2018 , 2017 and 2016 , respectively . as of december 31 , 2018 , we had an accumulated deficit of $ 294.4 million . we expect to continue to incur significant expenses and operating and net losses in the near future . our net losses may fluctuate significantly from quarter to quarter and year to year , depending on the timing of our clinical trials , the receipt of additional milestone payments , if any , under our licensing and collaborations with vfmcrp , maruishi and ckdp , the receipt of payments under any future collaborations and or licensing agreements we may enter into , and our expenditures on other r & d activities . we anticipate that our expenses will increase as we : continue the development of korsuva ( cr845/difelikefalin ) injection for ckd-ap in dialysis patients ; continue the development of oral korsuva ( cr845/difelikefalin ) for ckd-ap and other diseases associated with pruritus , such as cld-ap ; explore the potential to further develop i.v . cr845/difelikefalin in the post-operative setting ; conduct r & d of any potential future product candidates ; seek regulatory approvals for i.v . cr845/difelikefalin and any product candidates that successfully complete clinical trials ; establish a sales , marketing and distribution infrastructure and scale up external manufacturing capabilities to commercialize any products for which we may obtain regulatory approval ; maintain , expand and protect our global intellectual property portfolio ; hire additional clinical , quality control and scientific personnel ; and add operational , financial and management information systems and personnel , including personnel to support our drug development and potential future commercialization efforts . the successful development of any of our product candidates is highly uncertain . as such , at this time , we can not reasonably estimate or know the nature , timing and costs of the efforts that will be necessary to complete the development of i.v . cr845/difelikefalin , oral cr845/difelikefalin or our other current and future programs . we are also unable to predict when , if ever , we will generate any further material net cash inflows from cr845/difelikefalin . this is due to the numerous risks and uncertainties associated with developing medicines , including the uncertainty of : successful enrollment in , and completion of clinical trials ; receipt of marketing approvals from applicable regulatory authorities ; 86 establishing commercial manufacturing capabilities or making arrangements with third-party manufacturers ; obtaining and maintaining patent and trade secret protection and regulatory exclusivity for our product candidates ; launching commercial sales of the products , if and when approved , whether alone or in collaboration with others ; achieving meaningful penetration in the markets which we seek to serve ; and obtaining adequate coverage or reimbursement by third parties , such as commercial payers and government healthcare programs , including medicare and medicaid . a change in the outcome of any of these variables with respect to the development of i.v . cr845/difelikefalin , oral cr845/difelikefalin or any of our future product candidates would significantly change the costs and timing

