| Basis of Presentation and Summary of Significant Accounting Policies | Basis of Presentation and Summary of Significant Accounting Policies Business Ligand is a biopharmaceutical company with a business model based on developing or acquiring assets which generate royalty, milestone or other passive revenue for the Company using a lean corporate cost structure. We operate in one business segment: development and licensing of biopharmaceutical assets. Principles of Consolidation The accompanying consolidated financial statements include Ligand and its wholly-owned subsidiaries. All significant intercompany accounts and transactions have been eliminated in consolidation. Basis of Presentation Our consolidated financial statements have been prepared in accordance with U.S. GAAP and include the accounts of our parent company and its wholly-owned subsidiaries. All intercompany transactions and balances have been eliminated in consolidation. Reclassifications Certain reclassifications have been made to the previously issued statement of operations to conform with the current period presentation. See detail in Accounting Standards Recently Adopted subsection below for further information. Use of Estimates The preparation of consolidated financial statements in conformity with U.S. GAAP requires the use of estimates and assumptions that affect the amounts reported in the consolidated financial statements and the accompanying notes. Actual results may differ from those estimates. Concentrations of Business Risk Financial instruments that potentially subject to significant concentrations of credit risk consist primarily of cash equivalents and investments. We invest excess cash principally in United States government debt securities, investment grade corporate debt securities and certificates of deposit. We have established guidelines relative to diversification and maturities that maintain safety and liquidity. These guidelines are periodically reviewed and modified to take advantage of trends in yields and interest rates. A relatively small number of partners account for a significant percentage of our revenue. Revenue from significant partners, which is defined as 10% or more of our total revenue, was as follows: December 31, 2018 2017 2016 Partner A 40 % 46 % 41 % Partner B 13 % 19 % 14 % Partner C 20 % < 10% < 10% We obtain Captisol from two sites at a single supplier, Hovione. If this supplier were not able to supply the requested amounts of Captisol from each site, and if our safety stocks of material were depleted, we would be unable to continue to derive revenues from the sale of Captisol until we obtained material from an alternative source, which could take a considerable length of time. Cash Equivalents & Short Term Investments Cash equivalents consist of all investments with maturities of three months or less from the date of acquisition. Short-term investments primarily consist of investments in debt securities that have effective maturities greater than three months and less than twelve months from the date of acquisition. We classify our short-term investments as "available-for-sale". Such investments are carried at fair value, with unrealized gains and losses included in the statement of comprehensive income (loss). We determine the cost of investments based on the specific identification method. Accounts Receivable Trade accounts receivable are recorded at the net invoice value and are not interest bearing. We consider receivables past due based on the contractual payment terms which range from 30 to 90 days. We reserve specific receivables if collectability is no longer reasonably assured. We re-evaluate such reserves on a regular basis and adjust the reserves as needed. Once a receivable is deemed to be uncollectible, such balance is charged against the reserve. Inventory Inventory, which consists of finished goods, is stated at the lower of cost or market value. We determine cost using the first-in, first-out method. We analyze our inventory levels periodically and write down inventory to net realizable value if it has become obsolete, has a cost basis in excess of its expected net realizable value or is in excess of expected requirements. There were no write downs related to obsolete inventory recorded for the years ended December 31, 2018, 2017 and 2016. Property and Equipment Property and equipment are stated at cost, subject to review for impairment, and depreciated over the estimated useful lives of the assets, which generally range from three to ten years, using the straight-line method. Amortization of leasehold improvements is recorded over the shorter of the lease term or estimated useful life of the related asset. Maintenance and repairs are charged to operations as incurred. When assets are sold, or otherwise disposed of, the cost and related accumulated depreciation are removed from the accounts and any gain or loss is included in operating expense. Business Combinations The acquisition method of accounting for business combinations requires us to use significant estimates and assumptions, including fair value estimates, as of the business combination date and to refine those estimates as necessary during the measurement period (defined as the period, not to exceed one year, in which we may adjust the provisional amounts recognized for a business combination). Under the acquisition method of accounting, we recognize separately from goodwill the identifiable assets acquired, the liabilities assumed, including contingent consideration and all contractual contingencies, generally at the acquisition date fair value. Contingent purchase consideration to be settled in cash are remeasured to estimated fair value at each reporting period with the change in fair value recorded in other income (expense), net. Costs that we incur to complete the business combination such as investment banking, legal and other professional fees are not considered part of consideration and we charge them to general and administrative expense as they are incurred. We measure goodwill as of the acquisition date as the excess of consideration transferred, which we also measure at fair value, over the net of the acquisition date amounts of the identifiable assets acquired and liabilities assumed. In addition, IPR&D is capitalized and assessed for impairment annually. IPR&D is amortized upon product commercialization or upon out-licensing the underlying intellectual property where we have no active involvement in the licensee's development activities. IPR&D is amortized over the estimated life of the commercial product or licensing arrangement. Should the initial accounting for a business combination be incomplete by the end of a reporting period that falls within the measurement period, we report provisional amounts in our financial statements. During the measurement period, we adjust the provisional amounts recognized at the acquisition date to reflect new information obtained about facts and circumstances that existed as of the acquisition date that, if known, would have affected the measurement of the amounts recognized as of that date and we record those adjustments to our financial statements in the period of change, if any. Under the acquisition method of accounting for business combinations, if we identify changes to acquired deferred tax asset valuation allowances or liabilities related to uncertain tax positions during the measurement period and they relate to new information obtained about facts and circumstances that existed as of the acquisition date, those changes are considered a measurement period adjustment and we record the offset to goodwill. We record all other changes to deferred tax asset valuation allowances and liabilities related to uncertain tax positions in current period income tax expense. Contingent Liabilities In connection with the acquisition of Crystal in October 2017, we may be required to pay up to an additional $10.5 million in purchase consideration upon achievement of certain commercial and development milestones to the Crystal shareholders. In connection with the acquisition of CyDex in January 2011, we recorded a contingent liability for amounts potentially due to holders of the CyDex CVRs and former license holders. The liability is periodically assessed based on events and circumstances related to the underlying milestones, royalties and material sales. In connection with the acquisition of Metabasis in January 2010, we issued Metabasis stockholders four tradable CVRs for each Metabasis share. The fair values of the CVRs are remeasured at each reporting date through the term of the related agreement. Any change in fair value is recorded in our consolidated statement of operations. For additional information, see “ Note (4), Fair Value Measurement and Note (7), Balance Sheet Account Details .” Goodwill, Intangible Assets and Other Long-Lived Assets Goodwill, which has an indefinite useful life, represents the excess of cost over fair value of net assets acquired. Goodwill is reviewed for impairment at least annually during the fourth quarter, or more frequently if an event occurs indicating the potential for impairment. During the goodwill impairment review, we assess qualitative factors to determine whether it is more likely than not that the fair value of our reporting unit is less than the carrying amount, including goodwill. We operate in one reporting unit. The qualitative factors include, but are not limited to, macroeconomic conditions, industry and market considerations, and the overall financial performance. If, after assessing the totality of these qualitative factors, we determine that it is not more likely than not that the fair value of our reporting unit is less than the carrying amount, then no additional assessment is deemed necessary. Otherwise, we proceed to perform the two-step test for goodwill impairment. The first step involves comparing the estimated fair value of the reporting unit with the carrying value, including goodwill. If the carrying amount of the reporting unit exceeds the fair value, the second step of the goodwill impairment test is performed to determine the amount of loss, which involves comparing the implied fair value of the goodwill to the carrying value of the goodwill. We may also elect to bypass the qualitative assessment in a period and elect to proceed to perform the first step of the goodwill impairment test. We performed the annual assessment for goodwill impairment during the fourth quarter of 2018, noting no impairment. Our identifiable intangible assets are typically composed of acquired core technologies, licensed technologies, customer relationships and trade names. The cost of identifiable intangible assets with finite lives is generally amortized on a straight-line basis over the assets’ respective estimated useful lives. We regularly perform reviews to determine if any event has occurred that may indicate that intangible assets with finite useful lives and other long-lived assets are potentially impaired. If indicators of impairment exist, an impairment test is performed to assess the recoverability of the affected assets by determining whether the carrying amount of such assets exceeds the undiscounted expected future cash flows. If the affected assets are not recoverable, we estimate the fair value of the assets and record an impairment loss if the carrying value of the assets exceeds the fair value. Factors that may indicate potential impairment include a significant decline in our stock price and market capitalization compared to the net book value, significant changes in the ability of a particular asset to generate positive cash flows, and the pattern of utilization of a particular asset. Commercial license rights Commercial license rights consist of the following (in thousands): December 31, December 31, 2018 2017 Aziyo & CorMatrix $ 17,696 $ 17,696 Palvella 10,000 — Selexis 8,602 8,602 36,298 26,298 Less: accumulated amortization (4,838) (6,772) Total commercial license rights, net $ 31,460 $ 19,526 Commercial license rights represent a portfolio of future milestone and royalty payment rights acquired from Selexis in April 2013 and April 2015, CorMatrix in May 2016, and Pavella in December 2018. Individual commercial license rights acquired are accounted for as financial assets further discussed below. In December 2018, we entered into a development funding and royalties agreement with Palvella. Pursuant to the agreement, we will receive up to $8.0 million of milestone payments upon the achievement by Palvella of certain regulatory milestones for PTX-022, a product candidate being developed to treat pachyonychia congentia, and corporate and financing milestones. In addition to the milestone payments, Palvella will pay us tiered royalties from 5.0% to 9.8% based on aggregate annual worldwide net sales of any PTX-022 products, if approved, subject to Palvella’s right to reduce the royalty rates by making payments in certain circumstances. We paid Palvella an upfront payment of $10.0 million, which Palvella is required to use to fund the development of PTX-022. We will not incur any expenses to develop or commercialize PTX-022. Our director, Todd Davis, is also a director of Palvella, who beneficially owns 2% of Palvella's outstanding equity. Mr. Davis recused himself from all of the board's consideration of the purchase agreement between us and Palvella, including any financial analysis, the terms of the purchase agreement and the vote to approve the purchase agreement and the related transactions. In May 2017, we entered into a royalty agreement with Aziyo pursuant to which we will receive royalties from certain marketed products that Aziyo acquired from CorMatrix. Pursuant to the agreement, we received $10.0 million in 2017 from Aziyo to buydown the royalty rates on the products CorMatrix sold to Aziyo. The agreement closed on May 31, 2017, in connection with the closing of the asset sale from CorMatrix to Aziyo (the “CorMatrix Asset Sale”). Per the agreement, we will receive a 5% royalty on the products Aziyo acquired in the CorMatrix Asset Sale, reduced from the original 20% royalty from CorMatrix pursuant to the previously disclosed interest purchase agreement, dated May 3, 2016 (the “Original Interest Purchase Agreement”) between CorMatrix and us. In addition, Aziyo has agreed to pay us up to $10.0 million of additional milestones tied to cumulative net sales of the products Aziyo acquired in the CorMatrix Asset Sale and to extend the term on these royalties by one year. The royalty agreement will terminate on May 31, 2027. In addition, in May 2017, we entered into an amended and restated interest purchase agreement (the “Amended Interest Purchase Agreement”) with CorMatrix, which supersedes in its entirety the Original Interest Purchase Agreement. Other than removing the commercial products sold to Aziyo in the CorMatrix Sale, the terms of the Amended Interest Purchase Agreement remain unchanged with respect to the CorMatrix developmental pipeline products, including the royalty rate of 5% on such pipeline products. The Amended Interest Purchase Agreement will terminate 10 years from the date of the first commercial sale of such products. We account for the Aziyo commercial license right as a financial asset in accordance with ASC 310 and amortize the commercial license right using the effective interest method whereby we forecast expected cash flows over the term of the arrangement to arrive at an annualized effective interest. The annual effective interest associated with the forecasted cash flows from the royalty agreement with Aziyo as of December 31, 2018 is 26%. Revenue is calculated by multiplying the carrying value of the commercial license right by the effective interest. The payments received in 2018 were accordingly allocated between revenue and the amortization of the commercial license rights. We elected a prospective approach to account for changes in estimated cash flows and selected a method for determining when an impairment would be recognized and how to measure that impairment. In circumstances where our new estimate of expected cash flows is greater than previously expected, we will update our yield prospectively. While it has not occurred to date, in circumstances where our new estimate of expected cash flows is less than previously expected and below our original estimated yield we will record an impairment. Impairment will be recognized by reducing the financial asset to an amount that represents the present value of our most recent estimate of expected cash flows discounted by the original effective interest rate. In circumstances where our new estimate of expected cash flows is less than previously expected, but not below our original estimated yield, we will update our yield prospectively. We account for commercial license rights related to developmental pipeline products on a non-accrual basis. These developmental pipeline products are non-commercialized, non-approved products that require FDA or other regulatory approval, and thus have uncertain cash flows. The developmental pipeline products are on a non-accrual basis as we are not yet able to forecast future cash flows given their pre-commercial stages of development. We will prospectively update the yield model under the effective interest method once the underlying products are commercialized and we can reliably forecast expected cash flows. Income will be calculated by multiplying the carrying value of the commercial license right by the effective interest rate. Revenue Recognition Our revenue is generated primarily from royalties on sales of products commercialized by our partners, Captisol material sales, license fees and development, regulatory and sales based milestone payments. On January 1, 2018, we adopted ASC 606 which amends the guidance for recognition of revenue from contracts with customers by using the modified-retrospective method applied to those contracts that were not completed as of January 1, 2018. The results for reporting periods beginning January 1, 2018, are presented in accordance with the new standard, although comparative information has not been restated and continues to be reported under the accounting standards and policies in effect for those periods. Upon adoption, we recorded a net decrease of $25.6 million to accumulated deficit due to the cumulative impact of adopting the new standard, with the impact related primarily to the acceleration of royalty revenue, net of related deferred tax impact. See additional information in Disaggregation of Revenue subsection below. Our accounting policies under the new standard were applied prospectively and are noted below. Royalties, License Fees and Milestones We receive royalty revenue on sales by our partners of products covered by patents that we or our partners own under the contractual agreements. We do not have future performance obligations under these license arrangements. We generally satisfy our obligation to grant intellectual property rights on the effective date of the contract. However, we apply the royalty recognition constraint required under the guidance for sales-based royalties which requires a sales-based royalty to be recorded no sooner than the underlying sale. Therefore, royalties on sales of products commercialized by our partners are recognized in the quarter the product is sold. Our partners generally report sales information to us on a one quarter lag. Thus, we estimate the expected royalty proceeds based on an analysis of historical experience and interim data provided by our partners including their publicly announced sales. Differences between actual and estimated royalty revenues are adjusted for in the period in which they become known, typically the following quarter. Our contracts with customers often will include future contingent milestone based payments. We include contingent milestone based payments in the estimated transaction price when there is a basis to reasonably estimate the amount of the payment. These estimates are based on historical experience, anticipated results and our best judgment at the time. If the contingent milestone based payment is sales-based, we apply the royalty recognition constraint and record revenue when the underlying sale has taken place. Significant judgments must be made in determining the transaction price for our sales of intellectual property. Because of the risk that products in development with our partners will not reach development based milestones or receive regulatory approval, we generally recognize any contingent payments that would be due to us upon or after the development milestone or regulatory approval. Material Sales We recognize revenue when control of Captisol material or intellectual property license rights is transferred to our customers in an amount that reflects the consideration we expect to receive from our customers in exchange for those products. This process involves identifying the contract with a customer, determining the performance obligations in the contract, determining the contract price, allocating the contract price to the distinct performance obligations in the contract, and recognizing revenue when the performance obligations have been satisfied. A performance obligation is considered distinct from other obligations in a contract when it provides a benefit to the customer either on its own or together with other resources that are readily available to the customer and is separately identified in the contract. We consider a performance obligation satisfied once we have transferred control of the product, meaning the customer has the ability to use and obtain the benefit of the Captisol material or intellectual property license right. We recognize revenue for satisfied performance obligations only when we determine there are no uncertainties regarding payment terms or transfer of control. Sales tax and other taxes we collect concurrent with revenue-producing activities are excluded from revenue. We expense incremental costs of obtaining a contract when incurred if the expected amortization period of the asset that we would have recognized is one year or less or the amount is immaterial. We did not incur any incremental costs of obtaining a contract during the periods reported. Depending on the terms of the arrangement, we may also defer a portion of the consideration received because we have to satisfy a future obligation. We use an observable price to determine the stand-alone selling price for separate performance obligations or a cost plus margin approach when one is not available. We have elected to recognize the cost for freight and shipping when control over Captisol material has transferred to the customer as an expense in cost of material sales. The timing of revenue recognition, billings and cash collections results in billed accounts receivable, unbilled receivables (contract assets), and customer advances and deposits (contract liabilities) on the Consolidated Balance Sheet. Except for royalty revenue, we generally receive payment at the point we satisfy our obligation or soon after. Therefore, we do not generally carry a contract asset or deferred revenue balance. We have revenue sharing arrangements whereby certain revenue proceeds are shared with a third party. The revenue standard requires an entity to determine whether it is a principal or an agent in these transactions by evaluating the nature of its promise to the customer. We received a $4.6 million milestone payment from a license partner during 2018 of which $3.0 million was paid to a third-party in-licensor. We recorded net revenue of $1.6 million as we believe we are an agent in the transaction. We record amounts due to third-party in-licensors as general and administrative expenses when we are the principal in the transaction. Disaggregation of Revenue Under ASC 605, the legacy revenue standard, we would have reported total royalty revenue of $121.0 million during 2018, disaggregated as follows: Promacta $92.3 million, Kyprolis $20.9 million, Evomela $5.7 million, and Other $2.1 million. During 2017, royalty revenue continued to be reported in accordance with ASC 605 and was $88.7 million or disaggregated as follows: Promacta $62.9 million, Kyprolis $16.4 million, Evomela $7.2 million and Other $2.2 million. During 2016, royalty revenue continued to be reported in accordance with ASC 605 and was $59.4 million or disaggregated as follows: Promacta $43.0 million, Kyprolis $12.1 million, Evomela $1.4 million and Other $2.9 million. Under ASC 606, royalty revenue was $128.6 million during 2018 or disaggregated as follows: Promacta $99.3 million, Kyprolis $21.7 million, Evomela $5.7 million and Other $1.9 million. The following table represents disaggregation of Material Sales and License fees, milestone and other (in thousands), which are not affected by the adoption of ASC 606: Year ended December 31, 2018 2017 2016 Material Sales Captisol $ 29,123 $ 22,070 $ 22,502 License fees, milestones and other License fees 78,195 13,665 10,570 Milestones 6,577 11,093 16,091 Other 9,002 5,589 387 $ 93,774 $ 30,347 $ 27,048 Preclinical Study and Clinical Trial Accruals Substantial portions of our preclinical studies and all of our clinical trials have been performed by third-party laboratories, CROs. We account for a significant portion of the clinical study costs according to the terms of our contracts with CROs. The terms of the CRO contracts may result in payment flows that do not match the periods over which services are provided to us under such contracts. Our objective is to reflect the appropriate preclinical and clinical trial expenses in our financial statements in the same period as the services occur. As part of the process of preparing our financial statements, we rely on cost information provided by our CROs. We are also required to estimate certain of our expenses resulting from the obligations under the CRO contracts. Accordingly, our preclinical study and clinical trial accrual is dependent upon the timely and accurate reporting of CROs and other third-party vendors. We periodically evaluate our estimates to determine if adjustments are necessary or appropriate as more information becomes available concerning changing circumstances, and conditions or events that may affect such estimates. No material adjustments to preclinical study and clinical trial accrued expenses have been recognized to date. Research and Development Expenses Research and development expense consists of labor, material, equipment, and allocated facilities costs of our scientific staff who are working pursuant to our collaborative agreements and other research and development projects. Also included in research and development expenses are third-party costs incurred for our research programs including in-licensing costs, CRO costs and costs incurred by other research and development service vendors. We expense these costs as they are incurred. When we make payments for research and development services prior to the services being rendered, we record those amounts as prepaid assets on our consolidated balance sheet and we expense them as the services are provided. Share-Based Compensation We incur share-based compensation expense related to restricted stock, ESPP, and stock options. Restricted stock unit (RSU) and performance stock unit (PSU) are all considered restricted stock. The fair value of restricted stock is determined by the closing market price of our common stock on the date of grant. We recognize share-based compensation expense based on the fair value on a straight-line basis over the requisite service periods of the awards, taking into consideration of forfeitures. PSU represents a right to receive a certain number of shares of common stock based on the achievement of corporate performance goals and continued employment during the vesting period. At each reporting period, we reassess the probability of the achievement of such corporate performance goals and any expense change resulting from an adjustment in the estimated shares to be released are treated as a cumulative catch-up in the period of adjustment. We use the Black-Scholes-Merton option-pricing model to estimate the fair value of stock purchases under ESPP and stock options granted. The model assumptions include expected volatility, term, dividends, and the risk-free interest rate. We look to historical and implied volatilities of our stock to determine the expected volatility. The expected term of an award is based on historical forfeiture experience, exercise activity, and on the terms and conditions of the stock awards. The expected dividend yield is determined to be 0% given that except for 2007, during which we declared a cash dividend on our common stock of $2.50 per share, we have not paid any dividends on our common stock in the past and currently do not expect to pay cash dividends or make any other distributions on common stock in the future. The risk-free interest rate is based upon U.S. Treasury securities with remaining terms similar to the expected term of the share-based awards. We grant options, RSUs and PSUs to employees and non-employee directors. Non-employee directors are accounted for as employees. Options and RSUs granted to certain non-employee directors vest one year from the date of grant. Options granted to employees vest 1/8 on the six month anniversary of the date of grant, and 1/48 each month thereafter for forty-two months. RSUs and PSUs granted to employees vest over three years. All option awards generally expire ten years from the date of grant. Share-based compensation expense for awards to employees and non-employee directors is recognized on a straight-line basis over the vesting period until the last tranche vests. Derivatives In May 2018, we issued $750.0 million aggregate principal amount of 2023 Notes, bearing cash interest at a rate of 0.75% per year, payable semi-annually, as further described in “Footnote 6. Convertible Senior Notes.” Concurrently with the issuance of the notes, we entered into a series of convertible note hedge and warrant transactions which in combination are designed to reduce the potential dilution to our stockholders and/or offset the cash payments we are required to make in excess of the principal amount upon conversion of the notes. The conversion option associated with the 2023 Notes temporarily met the criteria for an embedded derivative liability which required bifurcation and separate accounting. In addition, the note hedge and warrants were also temporarily classified as a derivative asset and liability, respectively, on our consolidated balance sheet. As a result of shareholder approval to increase the number of authorized shares of our common stock on June 19, 2018, as discussed in “Footnote 6. Convertible Senior Notes,” the derivative asset and liabilities were reclassified to additional paid-in capital. Changes in the fair value of these derivatives prior to being classified in equity were reflected in other expense, net, in our consolidated statements of operations. The following table summarizes the inputs and assumptions used in the Black-Scholes model to calculate the fair value of the assets and the inputs and assumptions used in the Binomial model to calculate the fair value of the derivative liabilities associated with the 2023 Notes: As of May 22, 2018 As of June 19, 2018 Common stock price $187.09 $195.91 Exercise price, conversion premium and bond hedge $248.48 $248.48 Exercise price, warrant 315.38 315.38 Risk-free interest rate 2.9% 2.8% Volatility 30%-35% 30%-35% Dividend yield — — Annual coupon rate 0.75% 0.75% Remaining contractual term (in years) 5.05 4.98 In connection with our 2019 Notes, which we issued in August 2014 for $245.0 million aggregate principal amount, on May 22, 2018, we amended it making an irrevocable election to settle the entire note in cash. As a result, we reclassified from equity to derivative liability the fair value of the conversion premium as of May 22, 2018. Amounts paid in excess of the principal amount will be offset by an equal receipt of cash under the corresponding convertible bond hedge. As a result, we reclassified from equity to derivative asset the fair value of the bond hedge as of May 22, 2018. Changes in the fair value of these derivatives are reflected in other expense, net, in our condensed consolidated statements of operations. The following table summarizes the inputs and assumptions used in the Black-Scholes model to calculate the fair value of the derivative assets and the inputs and assumptio |
