alln-346 has demonstrated a robust reduction in both plasma and urine uric acid levels in an established urate oxidase knock-out mouse model , a severe animal model of hyperuricemia with advanced ckd and kidney damage due to urate crystal deposition . we presented preclinical data for alln-346 in october at the 2018 american college of rheumatology ( acr/arhp ) annual meeting . we are advancing our preclinical program for alln-346 and scaling our manufacturing processes for clinical studies . subject to the successful completion of these activities , we expect to file an ind for alln-346 with the fda in the second half of 2019 and to initiate our first clinical trial of alln-346 in patients with hyperuricemia in the first half of 2020. on november 6 , 2017 , we completed our ipo , in which we issued and sold 5,333,333 shares of our common stock at a public offering price of $ 14.00 per share , for aggregate gross proceeds of $ 74.7 million . the underwriters partially exercised their over-allotment option on december 1 , 2017 , and purchased 16,969 shares of our common stock , for aggregate gross 90 proceeds of $ 0.2 million . as a result of the ipo , we received approximately $ 67.0 million in net proceeds after deducting $ 7.9 million of underwriting discounts and commissions and offering costs . our operations to date have been limited to organizing and staffing our company , business planning , raising capital , developing our technology , identifying potential product candidates , producing drug substance and drug product material for use in preclinical studies and clinical trials , conducting preclinical studies of our product candidates and clinical trials for our lead product candidate , reloxaliase . we do not have any products approved for sale and have not generated any revenue to date . as of december 31 , 2018 , we had cash and cash equivalents totaling $ 61.6 million . we have incurred significant net operating losses in every year since our inception and expect to continue to incur significant expenses and increasing operating losses for the foreseeable future . our net losses may fluctuate significantly from quarter to quarter and year to year . our net losses were $ 35.6 million , $ 21.7 million and $ 24.5 million for the years ended december 31 , 2018 , 2017 and 2016 , respectively . as of december 31 , 2018 , we had an accumulated deficit of $ 117.6 million . we anticipate that our expenses will increase significantly as we : conduct future clinical trials of our lead product candidate , reloxaliase ; manufacture additional material for our pivotal phase 3 clinical program and potential future clinical studies we might conduct for our product candidates ; scale up our manufacturing process for reloxaliase to prepare for the filing of a potential biologics license application , or bla , and commercialization if our clinical development program is successful ; advance the development of alln-346 ; conduct research on the discovery and development of additional product candidates ; seek regulatory and marketing approvals for product candidates that successfully complete clinical trials , if any ; establish a sales , marketing and distribution infrastructure to commercialize any products for which we may obtain regulatory approval in geographies in which we plan to commercialize our products ourselves ; maintain , expand and protect our intellectual property portfolio ; hire additional staff , including clinical , scientific , technical , operational , and financial personnel , to execute our business plan ; and add clinical , scientific , operational , financial and management information systems to support our product development and potential future commercialization efforts , and to enable us to operate as a public company . we do not expect to generate revenue from product sales unless and until we successfully complete development and obtain regulatory approval for a product candidate . additionally , we currently use contract research organizations , or cros , and contract manufacturing organizations , or cmos , to carry out our preclinical and clinical development activities . we do not yet have a sales organization . if we obtain regulatory approval for our product candidates , we expect to incur significant commercialization expenses related to product sales , marketing , manufacturing and distribution . furthermore , we expect to incur additional costs associated with operating as a public company . accordingly , we may seek to fund our operations through public or private equity or debt financings or other sources , including strategic collaborations . we may , however , be unable to raise additional funds or enter into such other arrangements when needed on favorable terms or at all . our failure to raise capital or enter into such other arrangements as and when needed would have a negative impact on our financial condition and our ability to develop our current product candidates , or any additional product candidates , if developed . financial operations overview revenue to date , we have not generated any revenue from product sales or any other source and do not expect to generate any revenue from the sale of products for the foreseeable future . if our development efforts for reloxaliase or other product candidates that we may develop in the future are successful and result in marketing approval or collaboration or license 91 agreements with third parties , we may generate revenue in the future from a combination of product sales or payments from such collaboration or license agreements . story_separator_special_tag through december 31 , 2016 , the amount of stock-based compensation expense recognized in our consolidated financial statements was based on awards that were ultimately expected to vest . forfeitures were estimated at the time of grant and revised , if necessary , in subsequent periods if actual forfeitures differed from those estimates . the term “ forfeitures ” is distinct from “ cancellations ” or “ expirations ” and represents only the unvested portion of the surrendered option . the following table summarizes the classification of our stock-based compensation expense recognized in our statements of operations and comprehensive loss ( in thousands ) : replace_table_token_5_th as of december 31 , 2018 , we had $ 4.4 million of unrecognized compensation expense related to stock option awards , which is expected to be recognized over weighted-average remaining vesting periods of approximately 2.8 years . in future periods , we expect stock-based compensation expense to increase , due in part to our existing unrecognized stock-based compensation expense , potential increases in the value of our common stock and expected additional stock-based awards to continue to attract and retain our employees . determination of fair value of common stock as a private company with no active public market for our common stock prior to the completion of our ipo , our board of directors historically determined the fair value of our common stock on each date of grant , with input from management . our board of directors periodically determined the estimated per share fair value of our common stock at various dates using contemporaneous valuations performed in accordance with the guidance outlined in the american institute of certified public accountants practice aid , valuation of privately-held company equity securities issued as compensation , or the practice aid . once a public trading market for our common stock had been established in connection with the completion of our ipo , it is no longer be necessary for us to estimate the fair value of our common stock in connection with our accounting for stock options , as the fair value of our common stock will be its trading price on the nasdaq stock market . we performed contemporaneous valuations , with the assistance of a third-party specialist , as of november 6 , 2014 , february 15 , 2016 , december 31 , 2016 , april 30 , 2017 and august 31 , 2017 , which resulted in valuations of our common stock of $ 1.17 , $ 1.59 , $ 4.01 , $ 4.88 and $ 5.72 per share , respectively . in conducting the valuations , we considered all objective and subjective factors that we believed to be relevant for each valuation conducted , including our best estimate of our business condition , prospects and operating performance at each valuation date . within the valuations performed , a range of factors , assumptions and methodologies were used . the significant factors included : the lack of an active public market for our common stock and convertible preferred stock ; the prices at which we sold shares of our convertible preferred stock in arm 's length transactions and the superior rights , preferences and privileges of the convertible preferred stock relative to our common stock , including the liquidation preferences of our preferred stock ; our results of operations and financial condition , including cash on hand and borrowings under our credit facility ; the material risks related to our business ; our stage of development and business strategy ; 96 the composition of , and changes to , our management team and board of directors ; the market performance of publicly traded companies in the life sciences and biotechnology sectors , as well as recently completed initial public offerings , or ipos , of companies in the life sciences and biotechnology sectors ; and the likelihood of achieving a liquidity event such as an ipo given prevailing market conditions . historically , the dates of our contemporaneous valuations have not coincided with the dates of our stock-based compensation grants . in determining the exercise prices of the stock options granted , our board of directors considered , among other things , the most recent contemporaneous valuations of our common stock and our assessment of additional objective and subjective factors we believed were relevant as of the grant date . the additional factors considered when determining any changes in fair value of our common stock between the most recent contemporaneous valuation and the grant dates included the status of our stage of research and development , our operating and financial performance and current business conditions . there were significant judgments and estimates inherent in the determination of the fair value of our common stock . these judgments and estimates were management 's best estimates and included assumptions regarding our future operating performance , the time to completing an ipo or other liquidity event , the related company valuations associated with such events and the determinations of the appropriate valuation methods . if we had made different assumptions , our stock-based compensation expense , net loss and net loss per common share could have been different . warrant valuation we issued warrants to purchase shares of our series a and series c convertible preferred stock in conjunction with the advances made under our former credit facility with svb . these warrants were classified as liabilities as they either conditionally or unconditionally obligated us to transfer assets regardless of the timing of the redemption feature or price of the underlying convertible preferred stock . the warrants were initially recorded at their grant date fair value and were subject to revaluation at each balance sheet date . changes in the fair value of the warrants were recorded as a component of other income ( expense ) in the statements of operations and comprehensive loss , until the earlier of their exercise or expiration or the completion of a liquidation event , at which time

loss on extinguishment of debt on june 29 , 2018 , we terminated our loan agreement with svb . as a result we recorded a loss on extinguishment of debt of $ 0.6 million representing the unamortized debt discount and the final payment fee associated with the loan . comparison of the years ended december 31 , 2017 and 2016 the following table summarizes our results of operations for the years ended december 31 , 2016 and 2015 ( in thousands ) : replace_table_token_9_th research and development expense research and development expense decreased by $ 4.6 million from $ 20.1 million for the year ended december 31 , 2016 to $ 15.5 million for the year ended december 31 , 2017. the following table summarizes our research and development expenses for the years ended december 31 , 2017 and 2016 ( in thousands ) : replace_table_token_10_th the decrease in research and development expense was primarily attributable to the following : our clinical development external costs decreased by $ 3.2 million from $ 7.3 million for the year ended december 31 , 2016 to $ 4.1 million for the year ended december 31 , 2017. study 649 expense decreased by $ 2.0 million from $ 2.2 million for the year ended december 31 , 2016 to $ 0.2 million for the year ended december 31 , 2017. we enrolled our first subject into the trial in september 2015 , and completed enrollment in june 2016. the majority of enrollment and cro expenses were incurred during the year ended december 31 , 2016 ; 100 study 713 expense decreased by $ 1.3 million from $ 3.0 million for the year ended december 31 , 2016 to $ 1.7 million for the year ended december 31 , 2017. we enrolled our first subject into this


 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.
     ```loss on extinguishment of debt on june 29 , 2018 , we terminated our loan agreement with svb . as a result we recorded a loss on extinguishment of debt of $ 0.6 million representing the unamortized debt discount and the final payment fee associated with the loan . comparison of the years ended december 31 , 2017 and 2016 the following table summarizes our results of operations for the years ended december 31 , 2016 and 2015 ( in thousands ) : replace_table_token_9_th research and development expense research and development expense decreased by $ 4.6 million from $ 20.1 million for the year ended december 31 , 2016 to $ 15.5 million for the year ended december 31 , 2017. the following table summarizes our research and development expenses for the years ended december 31 , 2017 and 2016 ( in thousands ) : replace_table_token_10_th the decrease in research and development expense was primarily attributable to the following : our clinical development external costs decreased by $ 3.2 million from $ 7.3 million for the year ended december 31 , 2016 to $ 4.1 million for the year ended december 31 , 2017. study 649 expense decreased by $ 2.0 million from $ 2.2 million for the year ended december 31 , 2016 to $ 0.2 million for the year ended december 31 , 2017. we enrolled our first subject into the trial in september 2015 , and completed enrollment in june 2016. the majority of enrollment and cro expenses were incurred during the year ended december 31 , 2016 ; 100 study 713 expense decreased by $ 1.3 million from $ 3.0 million for the year ended december 31 , 2016 to $ 1.7 million for the year ended december 31 , 2017. we enrolled our first subject into this
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 Suspicious Activity Report : alln-346 has demonstrated a robust reduction in both plasma and urine uric acid levels in an established urate oxidase knock-out mouse model , a severe animal model of hyperuricemia with advanced ckd and kidney damage due to urate crystal deposition . we presented preclinical data for alln-346 in october at the 2018 american college of rheumatology ( acr/arhp ) annual meeting . we are advancing our preclinical program for alln-346 and scaling our manufacturing processes for clinical studies . subject to the successful completion of these activities , we expect to file an ind for alln-346 with the fda in the second half of 2019 and to initiate our first clinical trial of alln-346 in patients with hyperuricemia in the first half of 2020. on november 6 , 2017 , we completed our ipo , in which we issued and sold 5,333,333 shares of our common stock at a public offering price of $ 14.00 per share , for aggregate gross proceeds of $ 74.7 million . the underwriters partially exercised their over-allotment option on december 1 , 2017 , and purchased 16,969 shares of our common stock , for aggregate gross 90 proceeds of $ 0.2 million . as a result of the ipo , we received approximately $ 67.0 million in net proceeds after deducting $ 7.9 million of underwriting discounts and commissions and offering costs . our operations to date have been limited to organizing and staffing our company , business planning , raising capital , developing our technology , identifying potential product candidates , producing drug substance and drug product material for use in preclinical studies and clinical trials , conducting preclinical studies of our product candidates and clinical trials for our lead product candidate , reloxaliase . we do not have any products approved for sale and have not generated any revenue to date . as of december 31 , 2018 , we had cash and cash equivalents totaling $ 61.6 million . we have incurred significant net operating losses in every year since our inception and expect to continue to incur significant expenses and increasing operating losses for the foreseeable future . our net losses may fluctuate significantly from quarter to quarter and year to year . our net losses were $ 35.6 million , $ 21.7 million and $ 24.5 million for the years ended december 31 , 2018 , 2017 and 2016 , respectively . as of december 31 , 2018 , we had an accumulated deficit of $ 117.6 million . we anticipate that our expenses will increase significantly as we : conduct future clinical trials of our lead product candidate , reloxaliase ; manufacture additional material for our pivotal phase 3 clinical program and potential future clinical studies we might conduct for our product candidates ; scale up our manufacturing process for reloxaliase to prepare for the filing of a potential biologics license application , or bla , and commercialization if our clinical development program is successful ; advance the development of alln-346 ; conduct research on the discovery and development of additional product candidates ; seek regulatory and marketing approvals for product candidates that successfully complete clinical trials , if any ; establish a sales , marketing and distribution infrastructure to commercialize any products for which we may obtain regulatory approval in geographies in which we plan to commercialize our products ourselves ; maintain , expand and protect our intellectual property portfolio ; hire additional staff , including clinical , scientific , technical , operational , and financial personnel , to execute our business plan ; and add clinical , scientific , operational , financial and management information systems to support our product development and potential future commercialization efforts , and to enable us to operate as a public company . we do not expect to generate revenue from product sales unless and until we successfully complete development and obtain regulatory approval for a product candidate . additionally , we currently use contract research organizations , or cros , and contract manufacturing organizations , or cmos , to carry out our preclinical and clinical development activities . we do not yet have a sales organization . if we obtain regulatory approval for our product candidates , we expect to incur significant commercialization expenses related to product sales , marketing , manufacturing and distribution . furthermore , we expect to incur additional costs associated with operating as a public company . accordingly , we may seek to fund our operations through public or private equity or debt financings or other sources , including strategic collaborations . we may , however , be unable to raise additional funds or enter into such other arrangements when needed on favorable terms or at all . our failure to raise capital or enter into such other arrangements as and when needed would have a negative impact on our financial condition and our ability to develop our current product candidates , or any additional product candidates , if developed . financial operations overview revenue to date , we have not generated any revenue from product sales or any other source and do not expect to generate any revenue from the sale of products for the foreseeable future . if our development efforts for reloxaliase or other product candidates that we may develop in the future are successful and result in marketing approval or collaboration or license 91 agreements with third parties , we may generate revenue in the future from a combination of product sales or payments from such collaboration or license agreements . story_separator_special_tag through december 31 , 2016 , the amount of stock-based compensation expense recognized in our consolidated financial statements was based on awards that were ultimately expected to vest . forfeitures were estimated at the time of grant and revised , if necessary , in subsequent periods if actual forfeitures differed from those estimates . the term “ forfeitures ” is distinct from “ cancellations ” or “ expirations ” and represents only the unvested portion of the surrendered option . the following table summarizes the classification of our stock-based compensation expense recognized in our statements of operations and comprehensive loss ( in thousands ) : replace_table_token_5_th as of december 31 , 2018 , we had $ 4.4 million of unrecognized compensation expense related to stock option awards , which is expected to be recognized over weighted-average remaining vesting periods of approximately 2.8 years . in future periods , we expect stock-based compensation expense to increase , due in part to our existing unrecognized stock-based compensation expense , potential increases in the value of our common stock and expected additional stock-based awards to continue to attract and retain our employees . determination of fair value of common stock as a private company with no active public market for our common stock prior to the completion of our ipo , our board of directors historically determined the fair value of our common stock on each date of grant , with input from management . our board of directors periodically determined the estimated per share fair value of our common stock at various dates using contemporaneous valuations performed in accordance with the guidance outlined in the american institute of certified public accountants practice aid , valuation of privately-held company equity securities issued as compensation , or the practice aid . once a public trading market for our common stock had been established in connection with the completion of our ipo , it is no longer be necessary for us to estimate the fair value of our common stock in connection with our accounting for stock options , as the fair value of our common stock will be its trading price on the nasdaq stock market . we performed contemporaneous valuations , with the assistance of a third-party specialist , as of november 6 , 2014 , february 15 , 2016 , december 31 , 2016 , april 30 , 2017 and august 31 , 2017 , which resulted in valuations of our common stock of $ 1.17 , $ 1.59 , $ 4.01 , $ 4.88 and $ 5.72 per share , respectively . in conducting the valuations , we considered all objective and subjective factors that we believed to be relevant for each valuation conducted , including our best estimate of our business condition , prospects and operating performance at each valuation date . within the valuations performed , a range of factors , assumptions and methodologies were used . the significant factors included : the lack of an active public market for our common stock and convertible preferred stock ; the prices at which we sold shares of our convertible preferred stock in arm 's length transactions and the superior rights , preferences and privileges of the convertible preferred stock relative to our common stock , including the liquidation preferences of our preferred stock ; our results of operations and financial condition , including cash on hand and borrowings under our credit facility ; the material risks related to our business ; our stage of development and business strategy ; 96 the composition of , and changes to , our management team and board of directors ; the market performance of publicly traded companies in the life sciences and biotechnology sectors , as well as recently completed initial public offerings , or ipos , of companies in the life sciences and biotechnology sectors ; and the likelihood of achieving a liquidity event such as an ipo given prevailing market conditions . historically , the dates of our contemporaneous valuations have not coincided with the dates of our stock-based compensation grants . in determining the exercise prices of the stock options granted , our board of directors considered , among other things , the most recent contemporaneous valuations of our common stock and our assessment of additional objective and subjective factors we believed were relevant as of the grant date . the additional factors considered when determining any changes in fair value of our common stock between the most recent contemporaneous valuation and the grant dates included the status of our stage of research and development , our operating and financial performance and current business conditions . there were significant judgments and estimates inherent in the determination of the fair value of our common stock . these judgments and estimates were management 's best estimates and included assumptions regarding our future operating performance , the time to completing an ipo or other liquidity event , the related company valuations associated with such events and the determinations of the appropriate valuation methods . if we had made different assumptions , our stock-based compensation expense , net loss and net loss per common share could have been different . warrant valuation we issued warrants to purchase shares of our series a and series c convertible preferred stock in conjunction with the advances made under our former credit facility with svb . these warrants were classified as liabilities as they either conditionally or unconditionally obligated us to transfer assets regardless of the timing of the redemption feature or price of the underlying convertible preferred stock . the warrants were initially recorded at their grant date fair value and were subject to revaluation at each balance sheet date . changes in the fair value of the warrants were recorded as a component of other income ( expense ) in the statements of operations and comprehensive loss , until the earlier of their exercise or expiration or the completion of a liquidation event , at which time

