these types of restrictions may deter or prevent cancer patients from traveling to see their doctors and result in a decline in revenue for nerlynx , our only commercial product . additionally , our commercial team and sales force have limited travel and personal interactions with physicians and customers , including visits to healthcare provider offices due to limitations that have been imposed at certain hospitals and medical facilities , and are currently conducting a large percentage of promotional activities virtually . these types of restrictions have adversely impacted our ability to engage with our customers and have adversely impacted sales of nerlynx , our only commercial product , and they may continue to do so . the respective commercial teams of certain of the companies to which we sub-license the commercial rights to nerlynx , and on which we rely for our international sales , have chosen or have been forced to take similar action , and other sub-licensees of nerlynx may choose or be forced to take similar action . furthermore , the covid-19 pandemic has resulted in dramatic increases in unemployment rates , which may result in a substantial number of people becoming uninsured or underinsured . any of these developments may have an adverse effect on our revenue . we have observed disruptions in patient enrollments in the united states and in our summit basket trial . if the covid-19 pandemic continues to spread in the geographies in which we are conducting clinical trials , we may experience additional disruptions in those clinical trials , which could have a material adverse impact on our clinical trial plans and timelines . 63 our ability to continue to operate without any significant negative impacts will in part depend on the length and severity of the covid-19 pandemic and our ability to protect our employees and our supply chain . we continue to follow and monitor recommended actions of government and health authorities to protect our employees worldwide . for the year ended december 31 , 2020 , we and our key third-party suppliers and manufacturers were able to broadly maintain operations . we rely exclusively on third-party manufacturers to manufacture nerlynx . we intend to satisfy our near-term liquidity requirements through a combination of our existing cash and cash equivalents and marketable securities as of december 31 , 2020 and proceeds that will become available to us through product sales , royalties and sub-license milestone payments . however , this intention is based on assumptions that may prove to be wrong . changes may occur that would consume our available capital faster than anticipated , including the length and severity of the covid-19 pandemic and measures taken to control the spread of covid-19 , as well as changes in and progress of our development activities , the impact of commercialization efforts , acquisitions of additional drug candidates and changes in regulation . some of these developments have had and may continue to have an adverse effect on our revenue and thus could have an adverse effect on our ability to satisfy the minimum revenue covenants in our loan and security agreement . summary of income and expenses product revenue , net product revenue , net consists of revenue from sales of nerlynx . we sell nerlynx to a limited number of specialty pharmacies and specialty distributors in the united states . we record revenue at the net sales price , which includes an estimate for variable consideration for which reserves are established . variable consideration consists of trade discounts and allowances , product returns , provider chargebacks and discounts , government rebates and other incentives . license revenue license revenue consists of consideration earned for performance obligations satisfied pursuant to our sub-license agreements . royalty revenue royalty revenue consists of consideration earned related to product sales made by our sub-licensees in their respective territories pursuant to our license agreements . cost of sales cost of sales consists of third-party manufacturing costs , freight , and indirect overhead costs associated with sales of nerlynx . cost of product sales also includes period costs related to royalty charges payable to pfizer , the amortization of milestone payments under our license agreement with pfizer , certain inventory manufacturing services , inventory adjustment charges , unabsorbed manufacturing and overhead costs , and manufacturing variances . selling , general and administrative expenses selling , general and administrative , or sg & a , expenses , consist primarily of salaries and payroll-related costs , stock-based compensation expense , professional fees , business insurance , rent , general legal activities , credit loss expense and other corporate expenses . we expense sg & a expenses as they are incurred . research and development expenses research and development , or r & d , expenses include costs associated with services provided by consultants who conduct clinical services on our behalf , contract organizations for manufacturing of clinical materials and clinical trials . during the years ended december 31 , 2020 , 2019 and 2018 , our r & d expenses consisted primarily of clinical research organization , or cro , fees ; fees paid to consultants ; salaries and related personnel costs ; and stock-based compensation . we expense our r & d expenses as they are incurred . internal r & d expenses primarily consist of payroll-related costs and also include equipment costs , travel expenses and supplies . story_separator_special_tag in addition , we have based our estimate of capital needs on assumptions that may prove to be wrong . changes may occur that would consume our available capital faster than anticipated , including changes in and progress of our development activities , the impact of commercialization efforts , acquisitions of additional drug candidates and changes in regulation . potential sources of financing include strategic relationships , public or private sales of equity or debt and other sources of funds . we may seek to access the public or private equity markets when conditions are favorable due to our long-term capital requirements . if we raise funds by selling additional shares of common stock or other securities convertible into common stock , the ownership interests of our existing stockholders will be diluted . if we are not able to obtain financing when needed , we may be unable to carry out our business plan . as a result , we may have to significantly limit our operations , and our business , financial condition and results of operations would be materially harmed . in such an event , we will be required to undertake a thorough review of our programs , and the opportunities presented by such programs , and allocate our resources in the manner most prudent . off-balance sheet arrangements we do not have any “ off-balance sheet arrangements , ” as defined by the sec regulations . contractual obligations contractual obligations represent future cash commitments and liabilities under agreements with third parties and exclude contingent liabilities for which we can not reasonably predict future payment . our contractual obligations result from leases for office space and office equipment and the principal and interest owed under our credit facility . we also have unrecognized tax benefits that , if recognized , would affect the effective tax rate at december 31 , 2020. we do not have tax positions for which it is reasonably possible that the total amounts of unrecognized tax benefit will significantly increase or decrease within 12 months of the reporting date . additionally , the expected timing of payment of the obligations presented below is estimated based on current information . the following table represents our contractual obligations as of december 31 , 2020 , aggregated by type ( in thousands ) : replace_table_token_12_th 71 although we do have obligations for cro services , the table above excludes potential payments we may be required to make under our agreements with cros because timing of payments and actual amounts paid under those agreements may be different depending on the timing of receipt of goods or services or changes to agreed-upon terms or amounts for some obligations , and those agreements are cancelable upon written notice by us and therefore , not long-term liabilities . the contracts also contain variable costs and milestones that are hard to predict as they are based on such things as patients enrolled and clinical trial sites , which can vary and therefore , are also not included in the table above . the contracts held by us as of december 31 , 20 20 , are summarized as follows ( in thousands ) : replace_table_token_13_th in regard to our contractual obligations in relation to the pfizer in-license agreement , as consideration for the license , we are required to make substantial payments upon the achievement of certain milestones totaling approximately $ 187.5 million if all such milestones are achieved . the remaining milestone amounts were not included in the table above as the timing of when or if these payments will be made is uncertain . in connection with the fda approval of nerlynx in july of 2017 , we triggered a one-time milestone payment pursuant to the agreement . in june 2020 , we entered into a letter agreement with pfizer relating to the method of payment associated with a milestone payment under our license agreement with pfizer ( see note 14-commitments and contingencies in the accompanying notes to the financial statements ) . should we commercialize any more of the compounds licensed from pfizer or any products containing any of these compounds , we will be obligated to pay to pfizer annual royalties at a fixed rate in the low to mid-teens of net sales of all such products , subject to certain reductions and offsets in some circumstances . our royalty obligation continues , on a product-by-product and country-by-country basis , until the later of ( i ) the last to expire licensed patent covering the applicable licensed product in such country , or ( ii ) the earlier of generic competition for such licensed product reaching a certain level in such country or expiration of a certain time period after first commercial sale of such licensed product in such country . in the event that we sublicense the rights granted to us under the license agreement with pfizer to a third party , the same milestone and royalty payments are required . we can terminate the license agreement at will , or for safety concerns , in each case upon specified advance notice . see note 13—income taxes and note 14—commitments and contingencies in the accompanying notes to the financial statements for a summary of our uncertain tax positions and contracts held by us as of december 31 , 2020. as of december 31 , 2020 , the amount of unrecognized tax benefit was $ 3.3 million , and is also not included in the table above as the timing of when or if these payments will be made is uncertain . critical accounting policies the discussion and analysis of our consolidated financial condition and results of operations are based upon our consolidated financial statements , which have been prepared in conformity with gaap . the preparation of these consolidated financial statements requires us to make estimates and assumptions that affect the reported amounts of assets , liabilities , and expenses , and related disclosure of contingent

net cash provided by operating activities for the year ended december 31 , 20 20 included a net loss of $ 6 0.0 million , adjusted for non-cash items of approximately $ 36.6 million for stock-based compensation expense , approximately $ 10.0 million for depreciation and amortization , and $ 1.0 million for a provision for credit loss expense . further changes in cash flows from operations included an increase in accrued expenses of approximately $ 19 . 3 million , a de crease in accounts receivable , net of approximately $ 2.4 million , and a decrease in prepaid expenses and other of approximately $ 2.3 million . these changes were offset by a decrease in accounts payable of approximately $ 7.1 million , a n in crease in other current assets of approximately $ 3.1 million , and an increase in inventory , net of approximately $ 0.3 million , and other immaterial fluctuations . net cash used in operating activities for the year ended december 31 , 2019 , included a net loss of $ 75.6 million adjusted for non-cash items of approximately $ 57.3 million for stock-based compensation expense and approximately $ 8.1 million for depreciation and amortization , approximately $ 8.0 million for debt extinguishment fees and a loss of approximately $ 1.2 million for the impairment of an operating lease asset . further changes in cash flows from operations included an increase in accrued expenses of approximately $ 22.6 million , an increase in post-marketing commitment liability of approximately $ 9.0 million , a decrease in other current assets of approximately $ 1.5 million and a decrease in prepaid expenses and other of approximately $ 0.6 million . these changes were offset by an increase in accounts receivable , net of approximately $ 8.1 million , a decrease in accounts payable of approximately $ 1.5 million , an increase in inventory , net of approximately $ 0.5 million , and an increase in deferred rent of approximately $ 0.2 million . investing activities during the year ended december 31 , 2020 , cash provided by investing activities was approximately $ 23.4 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 provided by operating activities for the year ended december 31 , 20 20 included a net loss of $ 6 0.0 million , adjusted for non-cash items of approximately $ 36.6 million for stock-based compensation expense , approximately $ 10.0 million for depreciation and amortization , and $ 1.0 million for a provision for credit loss expense . further changes in cash flows from operations included an increase in accrued expenses of approximately $ 19 . 3 million , a de crease in accounts receivable , net of approximately $ 2.4 million , and a decrease in prepaid expenses and other of approximately $ 2.3 million . these changes were offset by a decrease in accounts payable of approximately $ 7.1 million , a n in crease in other current assets of approximately $ 3.1 million , and an increase in inventory , net of approximately $ 0.3 million , and other immaterial fluctuations . net cash used in operating activities for the year ended december 31 , 2019 , included a net loss of $ 75.6 million adjusted for non-cash items of approximately $ 57.3 million for stock-based compensation expense and approximately $ 8.1 million for depreciation and amortization , approximately $ 8.0 million for debt extinguishment fees and a loss of approximately $ 1.2 million for the impairment of an operating lease asset . further changes in cash flows from operations included an increase in accrued expenses of approximately $ 22.6 million , an increase in post-marketing commitment liability of approximately $ 9.0 million , a decrease in other current assets of approximately $ 1.5 million and a decrease in prepaid expenses and other of approximately $ 0.6 million . these changes were offset by an increase in accounts receivable , net of approximately $ 8.1 million , a decrease in accounts payable of approximately $ 1.5 million , an increase in inventory , net of approximately $ 0.5 million , and an increase in deferred rent of approximately $ 0.2 million . investing activities during the year ended december 31 , 2020 , cash provided by investing activities was approximately $ 23.4 million .
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 Suspicious Activity Report : these types of restrictions may deter or prevent cancer patients from traveling to see their doctors and result in a decline in revenue for nerlynx , our only commercial product . additionally , our commercial team and sales force have limited travel and personal interactions with physicians and customers , including visits to healthcare provider offices due to limitations that have been imposed at certain hospitals and medical facilities , and are currently conducting a large percentage of promotional activities virtually . these types of restrictions have adversely impacted our ability to engage with our customers and have adversely impacted sales of nerlynx , our only commercial product , and they may continue to do so . the respective commercial teams of certain of the companies to which we sub-license the commercial rights to nerlynx , and on which we rely for our international sales , have chosen or have been forced to take similar action , and other sub-licensees of nerlynx may choose or be forced to take similar action . furthermore , the covid-19 pandemic has resulted in dramatic increases in unemployment rates , which may result in a substantial number of people becoming uninsured or underinsured . any of these developments may have an adverse effect on our revenue . we have observed disruptions in patient enrollments in the united states and in our summit basket trial . if the covid-19 pandemic continues to spread in the geographies in which we are conducting clinical trials , we may experience additional disruptions in those clinical trials , which could have a material adverse impact on our clinical trial plans and timelines . 63 our ability to continue to operate without any significant negative impacts will in part depend on the length and severity of the covid-19 pandemic and our ability to protect our employees and our supply chain . we continue to follow and monitor recommended actions of government and health authorities to protect our employees worldwide . for the year ended december 31 , 2020 , we and our key third-party suppliers and manufacturers were able to broadly maintain operations . we rely exclusively on third-party manufacturers to manufacture nerlynx . we intend to satisfy our near-term liquidity requirements through a combination of our existing cash and cash equivalents and marketable securities as of december 31 , 2020 and proceeds that will become available to us through product sales , royalties and sub-license milestone payments . however , this intention is based on assumptions that may prove to be wrong . changes may occur that would consume our available capital faster than anticipated , including the length and severity of the covid-19 pandemic and measures taken to control the spread of covid-19 , as well as changes in and progress of our development activities , the impact of commercialization efforts , acquisitions of additional drug candidates and changes in regulation . some of these developments have had and may continue to have an adverse effect on our revenue and thus could have an adverse effect on our ability to satisfy the minimum revenue covenants in our loan and security agreement . summary of income and expenses product revenue , net product revenue , net consists of revenue from sales of nerlynx . we sell nerlynx to a limited number of specialty pharmacies and specialty distributors in the united states . we record revenue at the net sales price , which includes an estimate for variable consideration for which reserves are established . variable consideration consists of trade discounts and allowances , product returns , provider chargebacks and discounts , government rebates and other incentives . license revenue license revenue consists of consideration earned for performance obligations satisfied pursuant to our sub-license agreements . royalty revenue royalty revenue consists of consideration earned related to product sales made by our sub-licensees in their respective territories pursuant to our license agreements . cost of sales cost of sales consists of third-party manufacturing costs , freight , and indirect overhead costs associated with sales of nerlynx . cost of product sales also includes period costs related to royalty charges payable to pfizer , the amortization of milestone payments under our license agreement with pfizer , certain inventory manufacturing services , inventory adjustment charges , unabsorbed manufacturing and overhead costs , and manufacturing variances . selling , general and administrative expenses selling , general and administrative , or sg & a , expenses , consist primarily of salaries and payroll-related costs , stock-based compensation expense , professional fees , business insurance , rent , general legal activities , credit loss expense and other corporate expenses . we expense sg & a expenses as they are incurred . research and development expenses research and development , or r & d , expenses include costs associated with services provided by consultants who conduct clinical services on our behalf , contract organizations for manufacturing of clinical materials and clinical trials . during the years ended december 31 , 2020 , 2019 and 2018 , our r & d expenses consisted primarily of clinical research organization , or cro , fees ; fees paid to consultants ; salaries and related personnel costs ; and stock-based compensation . we expense our r & d expenses as they are incurred . internal r & d expenses primarily consist of payroll-related costs and also include equipment costs , travel expenses and supplies . story_separator_special_tag in addition , we have based our estimate of capital needs on assumptions that may prove to be wrong . changes may occur that would consume our available capital faster than anticipated , including changes in and progress of our development activities , the impact of commercialization efforts , acquisitions of additional drug candidates and changes in regulation . potential sources of financing include strategic relationships , public or private sales of equity or debt and other sources of funds . we may seek to access the public or private equity markets when conditions are favorable due to our long-term capital requirements . if we raise funds by selling additional shares of common stock or other securities convertible into common stock , the ownership interests of our existing stockholders will be diluted . if we are not able to obtain financing when needed , we may be unable to carry out our business plan . as a result , we may have to significantly limit our operations , and our business , financial condition and results of operations would be materially harmed . in such an event , we will be required to undertake a thorough review of our programs , and the opportunities presented by such programs , and allocate our resources in the manner most prudent . off-balance sheet arrangements we do not have any “ off-balance sheet arrangements , ” as defined by the sec regulations . contractual obligations contractual obligations represent future cash commitments and liabilities under agreements with third parties and exclude contingent liabilities for which we can not reasonably predict future payment . our contractual obligations result from leases for office space and office equipment and the principal and interest owed under our credit facility . we also have unrecognized tax benefits that , if recognized , would affect the effective tax rate at december 31 , 2020. we do not have tax positions for which it is reasonably possible that the total amounts of unrecognized tax benefit will significantly increase or decrease within 12 months of the reporting date . additionally , the expected timing of payment of the obligations presented below is estimated based on current information . the following table represents our contractual obligations as of december 31 , 2020 , aggregated by type ( in thousands ) : replace_table_token_12_th 71 although we do have obligations for cro services , the table above excludes potential payments we may be required to make under our agreements with cros because timing of payments and actual amounts paid under those agreements may be different depending on the timing of receipt of goods or services or changes to agreed-upon terms or amounts for some obligations , and those agreements are cancelable upon written notice by us and therefore , not long-term liabilities . the contracts also contain variable costs and milestones that are hard to predict as they are based on such things as patients enrolled and clinical trial sites , which can vary and therefore , are also not included in the table above . the contracts held by us as of december 31 , 20 20 , are summarized as follows ( in thousands ) : replace_table_token_13_th in regard to our contractual obligations in relation to the pfizer in-license agreement , as consideration for the license , we are required to make substantial payments upon the achievement of certain milestones totaling approximately $ 187.5 million if all such milestones are achieved . the remaining milestone amounts were not included in the table above as the timing of when or if these payments will be made is uncertain . in connection with the fda approval of nerlynx in july of 2017 , we triggered a one-time milestone payment pursuant to the agreement . in june 2020 , we entered into a letter agreement with pfizer relating to the method of payment associated with a milestone payment under our license agreement with pfizer ( see note 14-commitments and contingencies in the accompanying notes to the financial statements ) . should we commercialize any more of the compounds licensed from pfizer or any products containing any of these compounds , we will be obligated to pay to pfizer annual royalties at a fixed rate in the low to mid-teens of net sales of all such products , subject to certain reductions and offsets in some circumstances . our royalty obligation continues , on a product-by-product and country-by-country basis , until the later of ( i ) the last to expire licensed patent covering the applicable licensed product in such country , or ( ii ) the earlier of generic competition for such licensed product reaching a certain level in such country or expiration of a certain time period after first commercial sale of such licensed product in such country . in the event that we sublicense the rights granted to us under the license agreement with pfizer to a third party , the same milestone and royalty payments are required . we can terminate the license agreement at will , or for safety concerns , in each case upon specified advance notice . see note 13—income taxes and note 14—commitments and contingencies in the accompanying notes to the financial statements for a summary of our uncertain tax positions and contracts held by us as of december 31 , 2020. as of december 31 , 2020 , the amount of unrecognized tax benefit was $ 3.3 million , and is also not included in the table above as the timing of when or if these payments will be made is uncertain . critical accounting policies the discussion and analysis of our consolidated financial condition and results of operations are based upon our consolidated financial statements , which have been prepared in conformity with gaap . the preparation of these consolidated financial statements requires us to make estimates and assumptions that affect the reported amounts of assets , liabilities , and expenses , and related disclosure of contingent

